Tū Whakaruruhau: The evaluation of treatment outcomes for methamphetamine dependence in Aotearoa New Zealand – study protocol for a prospective longitudinal cohort study and longitudinal qualitative study

Tū Whakaruruhau: The evaluation of treatment outcomes for methamphetamine dependence in Aotearoa New Zealand – study protocol for a prospective longitudinal cohort study and longitudinal qualitative study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Study protocol Tū Whakaruruhau: The evaluation of treatment outcomes for methamphetamine dependence in Aotearoa New Zealand – study protocol for a prospective longitudinal cohort study and longitudinal qualitative study David A.L Newcombe, Sophia de Fossard, Rebecca McKetin, Vili Nosa, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6256539/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background : Methamphetamine is the second most used illicit drug in Aotearoa New Zealand, after cannabis. Regular and heavy users of methamphetamine are likely to develop methamphetamine use disorder (MUD), and significant health and psychiatric harm. Effective treatments for MUD are limited, and relapses are common. Tū Whakaruruhau is a programme of research that aims to understand what treatment approaches are effective in managing MUD and related physical and psychological harms, in New Zealand. Methods : Tū Whakaruruhau comprises two studies. The first study is a 24-month longitudinal cohort study that will follow people receiving treatment and those not in treatment for MUD (outpatient counselling, residential treatment, and detoxification) in the Auckland, Northland, and Waikato regions of New Zealand. Data collection will occur on entry to treatment (baseline), then 3-, 12-, and 24-months later. The primary outcome is self-reported methamphetamine use (days used in the past month) at 12-months. Secondary outcomes include psychiatric comorbidity, polydrug use, change in diagnosis of MUD, criminal involvement, healthcare utilisation, and expectations and experiences of treatment. Three hundred and twenty participants (50% indigenous Māori, 240 in the Treatment Group, 80 in the Non treatment Group) will be sought for 90% power on the primary outcome. The second study is a longitudinal qualitative study involving interviews at baseline, 6-, and 12-months with 30 participants (50% Māori) from the Treatment Group, to explore their expectations of treatment and lived experiences of treatment for MUD over time. Discussion: This programme of work will provide the first evidence of treatment outcomes for MUD and the relative effectiveness of the current approaches to treating MUD, in the New Zealand context. It will provide information on what factors predict better and more equitable health outcomes. The incorporation of qualitative interviews will ensure that the participants’ treatment experiences are captured. This will inform perspectives about what treatment approaches work, and do not work, so that the most appropriate interventions are made available to support consumer needs. Findings will be incorporated into relevant reviews, informing practice and policy. Study registration Australian and New Zealand Clinical Trial Registry: ACTRN12623000438651p. Registered 1 st May 2023. Methamphetamine Use Disorder Treatment Longitudinal Cohort Longitudinal Qualitative Māori Figures Figure 1 Background The prevalence of amphetamine-type stimulant use (including methamphetamine and amphetamine use) in Aotearoa New Zealand, has remained relatively stable over the last decade. In the 2023/2024 National Health Survey 1.3% (95% Confidence Interval [CI]: 1.0–1.6) of people aged ≥ 15 years of age reported using amphetamine-type stimulants in the past 12-months (56,000 adults nationally) (1). Subgroup analysis by ethnicity (i.e., for Māori, European, and Pacific) indicates no significant difference between groups. However, because methamphetamine use is illegal and highly stigmatized, these survey prevalence estimates are likely to be an underestimate (2). Although the reported prevalence of methamphetamine use is relatively low it is associated with notable public health and social consequences. For example, a 2023 study evaluating and ranking drug harms within New Zealand concluded that methamphetamine was the second most harmful drug (after alcohol) in terms of impact to the overall population (3). In 2016, the total cost of the harms attributable to the use of amphetamine type stimulant in New Zealand, including social costs and the costs of intervention, was estimated at NZ$364.2 million (4). Methamphetamine is a potent stimulant that increases monoamine (i.e., dopamine, noradrenaline, serotonin) (5). Methamphetamine’s action on dopaminergic pathways in the central nervous system (CNS) is thought to mediate its rewarding properties (i.e., euphoria) which underpin the development of addiction (6). Acute (short-term) effects of methamphetamine intoxication include arousal, euphoria, decreased appetite, behavioural disinhibition, alertness and sympathetic arousal (pupil dilation, increased body temperature, heart rate, blood pressure, and respiratory rate)(5). The negative sequelae of regular/heavy methamphetamine use can include the development of methamphetamine use disorder (MUD), a range of adverse physical (7–10) and psychiatric effects (11–14), and negative social outcomes (e.g. relationship breakdown, legal problems and financial problems) (7, 15). A typical pattern of use includes frequent, or binge use, over several days followed by an acute ‘crash’ phase of one to three days, although daily use is commonly observed in people who experience MUD. In this context, the crash phase is followed by a more prolonged withdrawal phase characterized by fatigue, appetite and mood disturbances, paranoia and drug craving. These withdrawal symptoms can result in people taking another dose of methamphetamine to relieve the symptoms of withdrawal (5). Given the adverse health and social risks associated with MUD, for many users there will be a desire and/or need to access treatment. There are currently no approved pharmacotherapies for MUD (16, 17). Psychosocial interventions that utilize aspects of cognitive behavioural therapy (CBT), contingency management, and motivational interviewing have been shown to be effective in reducing methamphetamine use in randomised controlled trials when compared to providing no treatment (18, 19). A recent systematic review of clinical trials has revealed the greater effect of contingency management, compared to CBT alone, or contingency management plus CBT, in promoting abstinence and reducing methamphetamine use (19). However, relapse back to methamphetamine use following treatment is common, with data from studies showing that up to 61% of clients relapse within the first year out of treatment, and only 13–14% remain abstinent after five years (20, 21). Treatment outcome studies are useful for evaluating the effectiveness of treatment for drug dependence as they have greater external validity than clinical trials and can determine what factors are predictive of good outcomes in real-world settings. However, existing treatment outcome studies have mainly focused on people who have alcohol use or heroin use disorder (22–25), and so their results are not generalisable to people who use methamphetamine. The United States Methamphetamine Treatment project (26) evaluated the Matrix model of treatment (an intensive outpatient treatment programme), compared to treatment as usual (out-patient counselling). The latter improved retention and reduced drug use, but improvements were not sustained following discharge (26). However, these results are not directly relevant to understanding the effectiveness of drug treatment in New Zealand, as the trial only examined psychosocial treatment delivered in US outpatient settings, when much of the drug treatment delivered in New Zealand is via residential treatment (27). Further, this study did not include a non-treatment arm (i.e. control group), making it difficult to conclude that methamphetamine use would not have remitted regardless of the intervention. The Australian Methamphetamine Treatment Evaluation Study (MATES) was a three-year longitudinal, prospective cohort study that examined treatment outcomes for people with MUD entering residential treatment (n = 248) or detoxification (n = 112) in Sydney and Brisbane, Australia. (20). The study included a quasi-control group of people who used methamphetamine in the community (n = 101). Participants were followed up at three months, one- and three-years after their baseline assessment. There were marked reductions in all measures of methamphetamine use for all groups over the study period. Relative to the control group, detoxification did not reduce methamphetamine use at any follow-up, but residential treatment significantly reduced methamphetamine use at all follow-ups (3-months: Odds Ratio (OR) 0.20, 95% CI: 0.13–0.33, p < 0.001; 1 year: OR 0.58; 95% CI 0.36–0.95: 3 years: OR 0.57, 95% CI 0.33–0.99, p = 0.0045). Improvements were also seen in other health outcomes (e.g., psychotic symptoms, hostility, anxiety disorders, crime, and human immunodeficiency virus (HIV) risk-taking behaviour. However, these results are not generalisable to New Zealand given its unique cultural and drug-using context - that is, in New Zealand frequent methamphetamine users are less likely to use methamphetamine intravenously than their counterparts in Australia (53% vs 86% respectively) (28). Furthermore, New Zealand has a substantial Māori population, who are the indigenous people of New Zealand, and so the Australian treatment experience cannot inform the nature of treatment responses needed for this population. There are limited New Zealand data published on the treatment effectiveness for people who access treatment for MUD. A New Zealand evaluation of treatment outcomes in clients discharged after 18 weeks of residential treatment for methamphetamine use found that many reported being abstinent at 3-months (81/86 clients), 6-months (59/64 clients), 9-months (46/50 clients), and at 12-months (34/39 clients) (27). The evaluation also noted reductions in the severity of psychological disorders evident on discharge remained stable during this time (27). However, the generalisability of the latter results to the wider New Zealand context is severely limited due to 1) the lack of a control group and failure to correct for loss-to-follow up; 2) the examination of limited health outcomes; and 3) the focus on residential treatment only. There is also a dearth of literature on the treatment outcomes for Māori who have MUD. Therefore, to address the need for a comprehensive evaluation of treatment effectiveness for MUD in New Zealand we designed a mixed methods programme of research (called Tū Whakaruruhau 1 ) that incorporates two studies: one a 24-month prospective longitudinal cohort study (based on MATES) and the other a 12-month longitudinal qualitative study. Objective The primary aim of Tū Whakaruruhau is to elucidate what treatment approaches (specifically, medically managed detoxification, inpatient residential rehabilitation and outpatient counselling/ behavioural support) are effective in managing MUD, and related physical and psychological harms, in New Zealand. The qualitative study will enable collection of information from a subset of methamphetamine users in treatment on their perspectives of what aspects of treatment worked for them. The secondary aim of Tū Whakaruruhau is to explore the relationship between treatment exposure and psychiatric co-morbidity, general wellbeing, health utilization, and criminal involvement, and particularly what client and treatment characteristics predict methamphetamine abstinence. Methods Consultation Consultation with treatment providers and those with lived experience of using methamphetamine was undertaken prior to the submission of the funding application. Following funding approval, significant time was spent developing and maintaining relationships with treatment providers), organisations that support and advocate for people with lived and living experience and government ministries and workforce development organizations. The core research team includes researchers with expertise in addiction and mental health, public health, study design and data analysis, Māori and Pacific Health and lived experience. The research is supported by a Māori Kaitiaki (Māori advisory group), a stakeholder advisory group, and a consumer advisory group. Throughout the study, consultation with these advisory groups will be undertaken to ensure that the study is conducted in a culturally appropriate and safe manner. Study 1: Longitudinal Cohort Study Design The study design is a prospective longitudinal cohort study. Two groups of people (Treatment Group, Non treatment Group) who report methamphetamine as their primary drug of concern will be recruited and followed-up for up to 24-months: The Treatment Group will include those who at baseline are enrolled in a formal treatment programme for their methamphetamine use; The Non treatment Group will be a comparison group (i.e., quasi-control group) and will include those who at baseline are not enrolled in any formal treatment. Data will be obtained from participants via face-to-face or video (Zoom) interviews at baseline, then at 3-, 12-, and 24-months post baseline. Participants A total of 320 individuals residing in New Zealand will be recruited. Eligible participants are those aged 18 years and over, who use methamphetamine and report that methamphetamine is their main drug of concern, can provide written consent, live in the Northland or greater Auckland/Hamilton regions of New Zealand, have access to a phone, are willing to provide contact details to facilitate follow-up, and are willing to provide follow-up information at scheduled time points. The Treatment Group includes individuals who are enrolled in a formal treatment programme (medically managed detoxification from methamphetamine, or residential treatment, or outpatient counselling/behavioural support) at the time of the screening interview. The Non treatment Group will include individuals who at the time of entry to the study are not in formal treatment for their substance use, but can be attending peer support groups, including narcotic anonymous, and support groups providing harm reduction advice. Furthermore, individuals in the Non treatment Group will need to score ≥ 4 on the Severity of Dependence Scale (SDS) (29) to ensure that their severity level of MUD is comparable to individuals in the Treatment Group. Individuals will be excluded if they have received any formal treatment for any substance use (as an inpatient or outpatient) or were imprisoned in the 30 days prior to either entering treatment (if being considered for the Treatment Group) or 30 days prior to the screening interview (if being considered in the Non treatment Group). Setting and Recruitment The study will be conducted in the top half of the North Island of New Zealand. Participants in the Treatment Group will be recruited from treatment services, both government-funded and non-governmental organisations, that provide mental health and addiction treatment. Recruitment will be facilitated using flyers placed on noticeboards, recruitment boxes (where those who are interested in participating in the study can provide their contact details), and treatment staff (clinicians) giving out flyers to prospective/interested participants. Participants in the Non treatment Group will be recruited from the general community (via study flyers at support group meetings, community libraries, needle-syringe exchanges, outreach services, and social housing sites). General methods to recruit individuals for both the Treatment and Non treatment Group will include media advertising, peer referral and promotion through local networks, and agencies and community groups, and peer networks. It is envisaged that recruitment will take place over approximately 20–24 months from the end of October 2023. Interested individuals will be required to make initial contact with a researcher (via phone, text message, or email) to indicate their interest in participating in the study. Study procedures Figure 1. shows the procedures for the study. Interested participants will be contacted by a researcher who will screen them for eligibility. If the individual is eligible, the researcher will organise to meet the participant to complete the screening/consent process. Participants will be provided a copy of the participant information sheet that summarises what participation in the study means and that they can provide consent or decline when the participant meets the researcher at the first face-to-face meeting. Once written consent is obtained, baseline data will be collected. At this first meeting, the participants’ contact details, and the contact details of two other people they know, will be collected and used to facilitate follow-up. In appreciation of their time, a koha (gift) of NZ$120 will be provided to each participant in the form of grocery vouchers. The koha will be divided into four equal amounts of NZ$30. Follow-up interviews will occur at 3–, 12-, and 24-months post baseline interview. Participants will be contacted by a member of the research team at the scheduled times using the contact details provided (i.e., by text if a mobile phone number has been provided, or email message). Initially a maximum of two attempts will be made to contact the participant, using the personal contact information provided. If this initial attempt to contact the participant is not successful then the research assistant will attempt to contact the participants' designated contact person. A maximum of two attempts will be made to contact the participants' designated contact person - if this fails the participant will be considered lost to follow-up. Data collection will be undertaken by graduate research assistants who have undertaken two weeks of intensive training prior to commencing interviewing. The training curriculum will cover material relevant to conducting research interviews of this type (including engagement and safety), cultural safety, psychiatric diagnoses, and administration of the battery of questionnaires (see Table 1). All training will be conducted by investigators who are health professionals and have qualifications/experience in addictions and mental health and counselling. Prior to commencing the research interviews, research assistants will be required to conduct role plays with professional actors to demonstrate their competence (particularly cultural competency), and fidelity to the guidelines for administration of the questionnaire battery. All data collection (with the exception of questions that make up The Mini International Neuropsychiatric Interview (M.I.N.I) (30), in order to adhere to the licencing agreement), will be collected and managed using REDCap (Research Electronic Data Capture). Table 1 Schedule of baseline and follow-up assessments for longitudinal cohort study. Timepoint Screen Interviews Baseline 3mth 12mth 24mth Eligibility Screening ✓ Informed consent ✓ Contact information ✓ ✓ ✓ Assessments: Descriptives Demographics: Age, gender, ethnicity, iwi, education ✓ General: living situation, employment status, prison history ✓ ✓ ✓ ✓ Treatment and substance use history ✓ Drug using history ✓ Primary outcome Methamphetamine use /abstinence last month [Q score] ✓ ✓ ✓ ✓ Secondary outcome measures Pre-treatment motivation ✓ Current drug use – other than methamphetamine [Q score] ✓ ✓ ✓ ✓ Days methamphetamine used in last month ✓ ✓ ✓ ✓ DSM-5 diagnosis of methamphetamine (stimulant) use disorder ✓ ✓ ✓ Level of methamphetamine dependence [(SDS] ✓ ✓ ✓ ✓ DSM-5 diagnosis of psychiatric co morbidity ✓ Severity of psychiatric symptoms [Psychosis screen] ✓ ✓ ✓ ✓ Severity of psychological distress ✓ ✓ ✓ ✓ Blood borne risk behaviour ✓ ✓ ✓ ✓ Treatment experience ✓ ✓ ✓ Criminal involvement ✓ ✓ ✓ ✓ Health service utilization ✓ ✓ ✓ ✓ Health-related quality of life ✓ ✓ ✓ ✓ General wellbeing ✓ ✓ ✓ ✓ Rapport/engagement with treatment staff [Index Treatment] ✓ Treatment modality/treatment characteristics [Index Treatment] ✓ Treatment exposure (treatment received) ✓ ✓ ✓ Data sources/ measurement The following general information will be collected at each timepoint: Employment status, living arrangement (alone, with partner, children, parents, non-related adults), income (net income past fortnight), accommodation (public housing, privately owned, parents’ home, boarding house/shelter, drug treatment, non-fixed address), prison history, motives for attending treatment (legal reasons, to maintain/regain custody of children), locator information (physical address, phone number of participant and contact details of at least two acquaintances), and whether deceased (post-baseline). The following baseline variables will be collected (Table 1). Demographic information : date of birth, gender, ethnicity, socio-economic position (based on highest level of education attained) detail will be collected. Those selecting Māori descent will be able to state their iwi/hapu (tribe/subtribes) and to indicate their connectedness to their iwi (Measured on a Likert scale: 1 = not very much to 5 = very much). Drug using history : Assessed using a modified version of the Addiction Severity Index-lite (31) to determine what drugs have been used in the participants lifetime. Addiction treatment history : Participants will be asked about the number and types of drug treatment they have started, not just for methamphetamine but also other psychoactive substances. Motivation to enter treatment for methamphetamine use [Treatment Group participants only] : Measured using the Treatment Entry Questionnaire (TEQ-9) (32). Psychiatric co-morbidity : The DSM-5 current/past psychiatric diagnoses (major depressive episode, manic or hypomanic episode, bipolar disorder, panic disorder, agoraphobia, social anxiety disorder, generalised anxiety disorder, PTSD, assessed using the M.I.N.I (30). Self-report DSM-5 Attention Deficit Hyperactivity Disorder [ADHD] : Measured using the Adult ADHD Self-Report Scale for DSM5 (ASRS-5) (33). Primary outcome: The primary outcome measure is self-reported methamphetamine use (days used last month) at 12-months provided by the Drug Use Section of the Opiate Treatment Index (OTI) in the form of the Q score. The Q score is a quantitative estimate of drug use quantity/frequency which is determined through the addition of consumption amounts on two previous days and dividing this value by the time intervals between these days during the preceding month (34). While the Q score is a continuous variable it will be considered a binary outcome in analyses: No use (abstinence): Use. Secondary outcome measures: Secondary outcomes will be assessed at baseline then at three, 12- and 24-months post baseline (Table 1). Symptoms of Psychosis : Measured using a screen for the presence of psychotic symptoms at each assessment (35). This screen will also include an item from the Brief Psychiatric Rating Scale that assesses hostility (36). Severity of Psychological Distress : Measured using the Kessler Psychological Distress Scale (K10) (37), at each assessment (max score = 50). The Kessler provides a global measure of psychological distress in the last month. Scores > 30 will be used as an indicator of severe distress, and interviewers will be required to follow the participants safety protocol outlined in the Study Fieldwork Safety Manual. DSM-5 diagnosis of stimulant (methamphetamine) use disorder Assessed using the M.I.N.I (30) at baseline,12, and 24-months only. Severity of stimulant (methamphetamine) dependence : Measured by the SDS (29) which contains five items (maximum score = 15) that assess the psychological components of dependence (impaired control, preoccupation, anxiety over drug use), and will provide a continuous measure that will help differentiate the severity of methamphetamine dependence. A cut-off score of ≥ 4 indicates methamphetamine dependence (38). Methamphetamine use : Assessed using two methods at each assessment: 1) The drug use section of the OTI will be used to determine the Q score for methamphetamine use (34); 2) The Time-line-Follow-Back (TLFB) to measure the frequency of methamphetamine use in the past 4 weeks (39). Continuous methamphetamine abstinence will be defined as no use of methamphetamine since baseline (20). Current general drug use (opiates, benzodiazepines, cannabis) use : Measured using the drug use section of the OTI, to determine the Q score for each drug of interest (29). Health-related quality of life (HRQoL) : Measured using the EuroQol- EQ-5D-five level version (EQ-5D-5L)(40), which assesses mobility, self-care, usual activities, pain/discomfort, anxiety/depression on three levels (no problems, some problems, extreme problems) Blood Borne Virus risk taking behaviour : Assessed using a modified version of the HIV risk taking behaviour scale [HRBS] of the OTI (34) (McKetin, personal communication). Criminal involvement : Assessed using the crime scale of the OTI (34) . Health Service Utilisation (HSU) : Measured using the HSU form (Centre for Health Economics Research and Evaluation, University of Sydney). General wellbeing : Measured using the Hua Oranga outcome questionnaire – this is a Māori measure of mental health outcome developed through the application of Te Whare Tapa Wha (Holistic approach to assess wellbeing) (41). Rapport with treatment staff : Measured using a scale that assesses staff support of patient goals; staff sincerity; ability to work with staff; treatment matched expectations; each item scored 1 to 4 to produce scores from 5 to 20 with higher scores indicating greater support (42). Descriptive measures Table 2 provides a definition of each treatment modality (residential treatment, medical detoxification and outpatient counselling) and the measures/methods used to describe the characteristics of treatment and assessment of treatment duration. Table 2 Description of the modality of the treatment, characteristics of the treatment agencies and treatment experienced by participants Definition of modality of treatment Characteristics of the treatment agencies and of the index treatment. Treatment exposure (Amount of treatment) Baseline/Index treatment : Will be defined as contiguous treatment (< 8 days gap between treatment episodes to allow for transfer between services) from intake to leaving treatment. The modality of treatment will be based on the main form of treatment provided during the baseline treatment episode and will be defined as either; 1) detoxification (usually brief, one week) inpatient/ outpatient withdrawal management with or without the use of medications), or; 2) residential rehabilitation that involves longer stays at residential settings that provide intensive therapeutic programmes, or; 3) o utpatient counselling where clients attend addiction services regularly for weeks or months to individual counselling sessions or group sessions Characteristics of the treatment service , including: • staff numbers, • staff to client ratio, • staff training (qualifications (discipline, experience in working in the mental health and addiction sector), • on site-training and supervision of staff. Characteristics of the treatment , including: • whether the treatment includes a follow-up program and whether the participant completes this, and; • whether they receive any medication during admission (antidepressants, antipsychotics, benzodiazepines etc). Treatment exposure: Indicators will include ; • number of counselling sessions (group & individual) completed (drug focused vs other issues considered) • completed days of treatment, total duration of treatment (from start to finish date). Collected at each assessment (for all participants); • Duration of treatment : Days of contiguous treatment (< 8 days gap) from intake to leaving treatment (including days spent in a detoxification unit (if required for admission to the baseline treatment). • Treatment re-entry : At each interview, participants will be asked how many treatment episodes they started since their last interview. The details of each episode will be described (modality, duration, completion) and whether they received treatment for methamphetamine • Treatment retention and completion: This is a dichotomous measure indicating having stayed in treatment (or not) for at least the median number of days for the baseline treatment modality (35 days for outpatient counselling, 19 days for residential rehabilitation, 5 days for detoxification). Treatment completion will be based on the participants’ self-report. Study size Two sample sizes have been calculated based on two rates of attrition, i.e., 20% and 30%, that will inform our recruitment processes. The first sample size is adjusted for 20% attrition and requires 320 participants (3:1 ratio: 240 in the Treatment Group, 80 in the Non treatment Group), the second requires 367 participants (3:1 ratio: 275 in the Treatment Group, 92 in the Non treatment group) to provide 90% power at p = 0.05 (2-sided alpha) to detect an absolute difference between the two groups of 20% in the proportion of participants at 12-months that have not used methamphetamine in the past month (assuming 40% in the Treatment Group and 20% in the Non treatment Group) based on findings from the MATES study (20). Equal numbers of participants in the Treatment Group will be sought from residential, detoxification and outpatient treatment settings, and at least 50% self-identifying as Māori across the whole study. Data Analyses All statistical analyses will be performed using SAS version 9.4 (SAS Institute Inc. Cary NC). Data analyses will be specified a priori in a statistical analysis plan prepared by the study statistician (VP). No interim analyses are planned. All baseline data will be summarised by treatment group. Treatment evaluations for the primary outcome will be carried out an intention-to-treat basis, with multiple imputation analysis used to account for missing data. Binary outcomes will be analysed using log-binomial regression analysis. The main analyses for the primary outcome will be adjusted for demographics (gender, ethnicity, age) psychiatric co-morbidity, polydrug use, baseline methamphetamine use disorder, treatment history and treatment re-entry during follow-up and any important imbalances in baseline covariates. To assess the robustness of the primary outcome various sensitivity analyses will also be conducted, including using the actual treatment the participant received during the follow-up rather than the index (baseline) treatment group, and assessing the impact of missing data such as complete case analysis. Repeated measures analysis will be used to assess change over time. To determine predictors of the outcomes (such as demographics, treatment exposure, and psychiatric diagnosis) multiple linear or log-binomial regression will be used as appropriate. The consistency of effects for prescribed subgroups (Māori status, age and sex) will be assessed using tests for heterogeneity. In order to eliminate any association between the treatment grouping and factors that predict treatment grouping the Inverse Probability of Treatment Weighted estimates of treatment outcomes derived by weighting the samples with the inverse of the ‘propensity to treat’ score will be used (20, 43). The impact of differential sample attrition (i.e., there may be differences in those not successfully followed up to those located and interviewed) will be corrected using the methods of Berk (1983) (44). The main predictor variable will be treatment exposure (indicated by retention in treatment, treatment completion, and dose (days) of treatment received). Covariates will include demographics (age, gender, employment status), psychiatric comorbidity, polydrug use, and dependence on MA at baseline. Missing data will be managed according to the following steps: 1) Follow-up of all individuals will be attempted, using all the contact information collected at consent. As the data is captured electronically the research assistants will be able to view who has completed, who has not, and what set of reminder notifications need to be sent; 2) For data collection time points 3-, 12-, and 24- months a two-week timeframe will be allowed for each follow-up assessment and so response intervals and frequency of questionnaire completion will be expected to vary between individuals. The two-week period post due date was selected as reasonable, as all participants will receive a notification one week before each data collection time point to organise a time to meet with the research assistant to complete the interview battery, and 3) If a participant misses a timeframe to contribute to a specific data point, it does not preclude them from completing the next data evaluation point when that falls due. Health economic evaluation Cost outcomes will include estimates of the costs of intervention (e.g., assessment), and treatment (e.g., counselling, residential treatment, detoxification) for methamphetamine use and health service utilisation costs (visit to emergency department, health practitioner visits, other health service utilisation costs and specific medications). Self-reported service use will be supplemented by electronic administrative data (i.e., the National Minimum Data Set for hospital admissions) obtained with consent. Using a resource-based costing approach that measures the inputs required to deliver a service (e.g., identify provision of care/number of visits) and applying market prices to each of these resources (e.g., cost/hour for healthcare visit). Unit costs will be sourced from published New Zealand data (where available), and where they are unavailable, published international data (once its applicability to New Zealand’s context is thoroughly assessed) or local estimates. Costs will be measured in 2025/6 New Zealand dollars. In addition, we will estimate the crime costs attributed to four different categories, property crime, dealing, fraud and violent crime (45). Cost analysis will include direct health care costs (i.e., healthcare services, prescription charges), indirect costs (cost of crime), and out of pocket expenses associated with the Treatment Group compared with the Non treatment Group. Cost offsets refer to the scenario where costs of crime and health service utilisation play an important role in the cost-reductions (cost-savings) over a period of 2 years. These cost-savings are likely due to overall lower level of crime activity and health service utilisation patterns among participants in the Treatment Group compared with the Non treatment Group. If feasible, a cost-effectiveness analysis will be conducted under the Consolidated Health Economic Evaluation Reporting Guidelines (46) to examine the likely impact of methamphetamine treatment aimed at reducing methamphetamine use and related harms in the New Zealand context. The EQ-5D scores (40) will be transformed into quality-adjusted life years (QALYs) using the ‘area under the curve’ method (47). Methamphetamine use at 12 months (abstinent days last month) will be the clinical benefit measure. An incremental cost-effectiveness ratio will be calculated to compare additional costs and health benefits associated with the Treatment Group compared with the Non treatment Group. For data linkage, the participants will be asked to consent to data being sought from the Ministry of Health on the number of times they had been admitted to hospital, seen in the emergency department or had an outpatient visit (healthcare utilisation, for example counselling and treatment) from recruitment until 2 years. Similarly, with consent, we will seek information on the number of charges and convictions relating to property crime, dealing fraud and violent crime to estimate the cost of crime attributable to MUD. With consent, the participants’ National Health Index number will be provided to the Ministry of Health for linkage to their healthcare utilisation data. Their inland revenue department number will be provided to the Ministry of Justice for linking with the cost of crime Study 2: Longitudinal Qualitative Study Design A longitudinal qualitative research design will be utilised to explore treatment goals, perceptions of treatment effectiveness, and treatment outcomes. Longitudinal qualitative research has been previously utilised in health research to explore the lived experiences of patients about treatment and change over time (48–50), and will be a valuable addition to the longitudinal cohort study. Each participant enrolled in the Longitudinal Qualitative Study will be asked to attend three interviews across a 12-month period. Participants Thirty participants from the Treatment Group of study 1 will be recruited, over 12 months. Setting See Study 1. Sampling Sampling will be purposive. Equal numbers of participants will be recruited from residential, detoxification and outpatient treatment settings, and at least 50% will self-identify as Māori. Recruitment and follow up Participants in Study 1 will be asked whether they consent to participation in the Longitudinal Qualitative Study at the initial baseline interview for the Longitudinal Cohort Study. Purposive sampling will be undertaken from this consented group. The procedures used to follow up participants for the cohort study will be utilised to follow-up participants in the Longitudinal Qualitative Study. Data collection Participants will be interviewed at baseline, 6 months and 12 months. To avoid fatigue, the baseline and 12-month Longitudinal Qualitative Study interviews will be carried out at different times from the interviews for the Longitudinal Cohort Study. All interviews will be audio recorded. Participants in the Longitudinal Qualitative Study will receive a gift (koha) of $90 which will be provided to each participant in the form of grocery vouchers ($30 for each interview they attend). Data collection will be undertaken by the same research assistants working on the cohort study (Study 1). The research assistants will receive training on undertaking semi-structured, qualitative interviews and will undergo peer review of their practice sessions with trained actors. A particular focus of the training will be the use of prompts to encourage more in-depth discussion of key areas/concepts and probing to encourage more detailed descriptions. Research questions The questions asked during the interviews will broadly explore participants’ experiences, and expectations of treatment, and treatment outcomes at baseline and follow-up interviews. Baseline questions will explore if anything relevant has happened in the 2 months prior to entering treatment, participants’ reasons for entering treatment, and what participants want to get out of treatment. Further questions will explore if treatment is what they expected, what aspects of treatment are working for them, and if they have any suggestions to improve treatment. At the 6- and 12- months interviews participants will be asked if they are still in treatment, and if they are, why, and if treatment is what they expected. Participants will then be asked what has been working for them. Participants will also be asked if they have any suggestions to improve treatment. If the participants are not in treatment at the time of the interview, they will be asked why they left treatment, and if they have any suggestions to improve treatment. Participants will also be asked about their methamphetamine and other substance use at each interview. Those who have relapsed will be asked what, if any, aspects of treatment have proved helpful in dealing with their MUD and whether they have suggestions to improve this aspect of treatment. Qualitative Data Management and Analysis All interviews for the Longitudinal Qualitative Study will be audio recorded and transcribed verbatim by a local professional transcription service and stored in a secure file. To maintain the quality of these interviews the following plan will be followed: after 10 baseline interviews have been completed, each research assistant will listen to one of their interviews, and one other from another research assistant, and reflect on several aspects (including building rapport, use of clarification questions). Research assistants will be required to keep field notes regarding whether the interview was cut short, and why, any significant events in the interview, such as interruptions, and any concerns they may have about participants. Analysis will be diachronic (after all data collection has been completed) and take a thematic approach with a combination of deductive (explaining findings from the quantitative data) and inductive (allowing new themes to emerge, to identify pathways and change over time (see (48) ). A deductive coding framework will be developed based on the interview guide and all interviews will be coded by one person. Inductive codes (new codes arising as part of the coding process) will be added later during the coding process. Analysis will be guided by an iterative categorisation technique (51). A combination of cross-sectional baseline analysis, followed by trajectory analysis by wave (baseline, 6- and 12-months) will be undertaken. All Māori data analysis will be undertaken through a Māori lens overseen by the principal Māori investigator (TP) and the Māori governance group. Ethical considerations and dissemination Both studies have been approved by the New Zealand Health and Disability Ethics Committee (Ref: 2023 EP 15148) and any changes will be reported as per ethics standard operating procedures and policies. This programme of work is also registered with the Australian and New Zealand Clinical Trial Registry (ACTRN12623000438651p), and the protocol conforms to the STROBE statement (52). A dissemination plan has been drafted and will be updated as the study progresses. Investigators are required to sign this document and indicate their understanding of what constitutes authorship of scientific outputs (according to International Committee of Medical Journal of Editors (ICMJE) Guidelines) (53). Findings will be shared by publication in peer reviewed journals and presentations at local and international conferences. Dissemination of findings will include feedback to participants (via the study website and summaries presented at recruitment sites), national media releases at the time of journal publication and presentations at local, national and international audiences. Bespoke arrangements will be made for local presentations to reflect the different audiences (treatment services, government (Policy and workforce groups, advocacy groups) across New Zealand likely to be interested. Discussion Tū Whakaruruhau will be unique in that it is the first programme of research that promises to provide evidence of the effectiveness of standard approaches (medical detoxification, residential treatment and community approaches) in the treatment of MUD in the New Zealand context. The longitudinal cohort study (Study 1) will provide a clearer understanding of what predicts better, more equitable, and cost-effective health outcomes for people living with MUD in New Zealand. The findings from this work will inform treatment guidelines and relevant evidence reviews. The recruitment of at least 50% of participants who identify as Māori will ensure appropriate representation of the indigenous voice in this study. Further, the addition of a longitudinal qualitative arm (Study 2) to the research programme will provide the opportunity for people living with MUD to say what they believe is working for them and to advocate for the use of intervention/treatment approaches they believe would improve treatment. The development of this programme of work has been guided by Māori researchers and practitioners on the study investigator team and a Māori advisory group to ensure that it incorporates a Māori culturally world view (Te Ao Māori). This is to ensure that the rights of Māori, who are the indigenous people of NZ, are upheld. Findings from Tū Whakaruruhau will inform and provide the basis for the ongoing establishment of an evidence base for treatment for problematic methamphetamine use (including MUD) in Aotearoa New Zealand. This paper reports on the protocol version 1.1, 7th July 2023 and that has ethical approval. The study design has been peer reviewed as part of the funding process. This study is currently ongoing; recruitment started in December 2023. Recruitment will cease July, 2025. The final follow-up is expected in June 2027. Abbreviations ADHD Attention Deficit Hyperactivity Disorder ASRS-5 Adult ADHD Self-Report Scale CBT Cognitive Behavioural Treatment CI Confidence Intervals CNS Central Nervous System DSM-5 Diagnostic Statistical Manual – 5th Edition EQ-5D-5L EuroQuol − 5D-5L HIV Human immunodeficiency Virus HRBS HIV risk taking behaviour scale HRQuol Health related quality of life HSU Health service utilisation ICMJE International Committee of Medical Journal Editors K10 Kessler MATES Methamphetamine Treatment Evaluation Study M.I.N.I Mini-International Neuropsychiatric Interview MUD Methamphetamine use disorder NGO Non-governmental organization OTI Opiate Treatment Index OR Odds Ratio QALY’s Quality adjusted life years REDCap Research Electronic Data Capture SDS Substance Dependence Scale TEQ-9 Treatment Entry Questionnaire TLB Timeline Follow Back US United States of America Declarations Ethics approval and consent to participate This programme of work was approved by the New Zealand Central Health and Disability Ethics Committees (reference: 2023 EP 15148). Ethics approval for any amendments to the study protocol will be sought. Maintenance of confidentiality and compliance with NZ’s Privacy Act will be emphasised to all study participants. Participation in the study will be entirely voluntary. Written consent will be obtained from all participants for both studies prior to enrolling in the study. All data collected for Study 1 will be entered, stored and backed-up in a secure manner via an internet data management system. Qualitative data from study 2 will be initially stored as audio files on a secure password protected site prior to transcription. Transcription will be undertaken by a local transcription company that is ISO9001 and ISO27001 accredited. The transcription company will be required to sign and adhere to a data management agreement. Transcription will be undertaken by transcribers based in New Zealand. Both the recoding and transcription will be securely stored until after the study has finished to allow researchers to check that the transcription was accurate. Once the researchers have finished the analysis the audio recordings will be destroyed. If any participants suffer harm from study participation, they will be eligible for compensation via their private health or life insurance, or via NZ’s Accident Compensation Corporation (ACC) scheme. Consent for publication No identifiable individual participant data (names or other personal identifiers) are contained in this manuscript. Availability of data and materials The datasets that will be used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests No authors have received financial support from any companies for the submitted work. All authors declare that they have no competing interests. Funding This study is funded by a 40-month project grant from the Health Research Council of New Zealand (22/327). The study protocol has undergone peer review by the funding body. Top-up funding is been sought to enable follow-up of all 24-month interviews and more comprehensive data linkage. Funders will not be involved in the design of the study, collection, analysis and interpretation of the data. Authors contributions Authorship complies with the ICMJE authorship eligibility guidelines. DN, RM and PA developed the initial overall study design; DN, RM, PA, NW, JS, RR, BTA, VN, VP sought and obtained funding for the study and wrote the study protocol. SdF is the project manager responsible for the day-to-day running of the study. PA and later TP (following the death of PA) lead the Māori Governance group for the study. JS and CW lead study 2. CW will lead the longitudinal qualitative analysis. DN, RR, SF, JS, PA and CW will be involved in training of the research assistants. VP will undertake all data analysis for the longitudinal cohort study. BTA will undertake health economic analyses. All investigators are members of the research steering committee. DN led the preparation of the manuscript. DN is guarantor for this paper. All authors have read and approved the final manuscript. Corresponding Author Correspondence to David Newcombe Acknowledgements We acknowledge Whaea (Aunty) Pam Armstrong who with DN conceived the original idea for the study and was an investigator on Tū Whakaruruhau until her death in 2024. We wish to acknowledge Auckland Uni-Services staff involved in study management and data management processes, and members of the Māori governance group who provide overarching cultural advice and encouragement – initially under the guidance of Whaea Pam Armstrong, and currently Te Rōpu Poa. We also acknowledge the team of research assistants for their passion, commitment for this project and tenacity in recruiting and following up participants. We also thank members of the consumer advisory committee. We thank all the treatment providers and health professional for their support of, and promotion of this study to people who use methamphetamine, and who make it possible to recruit participants Authors Information 1 Department of Social and Community Health, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. 2 Centre for Addiction Research, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. 3 National Institute for Health Innovation, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. 4 National Drug and Alcohol Research Centre, Randwick Campus, University of New South Wales, NSW 2013, Australia. 5 Department of Pacific Health, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. 6 Ministry of Māori Development, 85-87 Cameron Street, Whangarei 0110, New Zealand. 7 Department of Health Systems, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand Footnotes 1. Tū Whakaruruhau is a te reo (Māori language) name gifted by the study Māori advisory committee. Translated the name means ‘to stand as a protection, to be a beacon of manaakitanga (to show respect and care for others)’. References Ministry of Health. Annual Data Explorer 2023/2024: New Zealand Health Survey. Wellington: Ministry of Health. Chan GC, Sun T, Lim C, Stjepanović D, Rutherford B, Johnson B, et al. Did the under-reporting of meth/amphetamine use increase in a general population survey in Australia as negative media coverage increased? Addiction. 2022;117(6):1787–93. Crossin R, Cleland L, Wilkins C, Rychert M, Adamson S, Potiki T, et al. The New Zealand drug harms ranking study: A multi-criteria decision analysis. J Psychopharmacol. 2023;37(9):891–903. McFadden C. Researh Report: The New Zealand Drug Harm Index 2016. Ministry of Health; 2016. Cruickshank CC, Dyer KR. A review of the clinical pharmacology of methamphetamine. Addiction. 2009;104(7):1085–99. Volkow ND, Michaelides M, Baler R. The neuroscience of drug reward and addiction. Physiol Rev. 2019;99(4):2115–40. Darke S, Kaye S, McKetin R, Duflou J. Major physical and psychological harms of methamphetamine use. Drug Alcohol Rev. 2008;27(3):253–62. Kaye S, McKetin R, Duflou J, Darke S. Methamphetamine and cardiovascular pathology: a review of the evidence. Addiction. 2007;102(8):1204–11. Turnipseed SD, Richards JR, Kirk JD, Diercks DB, Amsterdam EA. Frequency of acute coronary syndrome in patients presenting to the emergency department with chest pain after methamphetamine use. J Emerg Med. 2003;24(4):369–73. Perez JA Jr, Arsura EL, Strategos S. Methamphetamine-related stroke: four cases. J Emerg Med. 1999;17(3):469–71. McKetin R, Lubman DI, Baker AL, Dawe S, Ali RL. Dose-related psychotic symptoms in chronic methamphetamine users: evidence from a prospective longitudinal study. JAMA psychiatry. 2013;70(3):319–24. Connell PH. Amphetamine psychosis Maudsley Monographs No5. London: Oxford University Press; 1958. McKetin R, Dawe S, Burns RA, Hides L, Kavanagh DJ, Teesson M, et al. The profile of psychiatric symptoms exacerbated by methamphetamine use. Drug Alcohol Depend. 2016;161:104–9. Simon SL, Dean AC, Cordova X, Monterosso JR, London ED. Methamphetamine dependence and neuropsychological functioning: evaluating change during early abstinence. JSAD. 2010;71(3):335–44. Sommers I, Baskin D, Baskin-Sommers A. Methamphetamine use among young adults: health and social consequences. Addict Behav. 2006;31(8):1469–76. Sharafi H, Bakouni H, McAnulty C, Drouin S, Coronado-Montoya S, Bahremand A, et al. Prescription psychostimulants for the treatment of amphetamine‐type stimulant use disorder: a systematic review and meta‐analysis of randomized placebo‐controlled trials. Addiction. 2024;119(2):211–24. Farrell M, Martin NK, Stockings E, Bórquez A, Cepeda JA, Degenhardt L, et al. Responding to global stimulant use: challenges and opportunities. Lancet. 2019;394(10209):1652–67. Minozzi S, Saulle R, De Crescenzo F, Amato L. Psychosocial interventions for psychostimulant misuse. Cochrane Database Syst Reviews. 2016(9). AshaRani P, Hombali A, Seow E, Ong WJ, Tan JH, Subramaniam MJD, et al. Non-pharmacological interventions for methamphetamine use disorder: a systematic review. Drug Alcohol Depend. 2020;212:108060. McKetin R, Najman JM, Baker AL, Lubman DI, Dawe S, Ali R, et al. Evaluating the impact of community-based treatment options on methamphetamine use: findings from the Methamphetamine Treatment Evaluation Study (MATES). Addiction. 2012;107(11):1998–2008. Brecht M-L, Herbeck D. Time to relapse following treatment for methamphetamine use: a long-term perspective on patterns and predictors. Drug Alcohol Depend. 2014;139:18–25. Hser Y-I, Hoffman V, Grella CE, Anglin MD. A 33-year follow-up of narcotics addicts. Arch Gen Psychiatry. 2001;58(5):503–8. Hubbard RL, Craddock SG, Anderson J. Overview of 5-year followup outcomes in the drug abuse treatment outcome studies (DATOS). J Subst Abuse Treat. 2003;25(3):125–34. Gossop M, Marsden J, Stewart D, Kidd T. The National Treatment Outcome Research Study (NTORS): 4–5 year follow-up results. Addiction. 2003;98(3):291–303. Teesson M, Mills K, Ross J, Darke S, Williamson A, Havard A. The impact of treatment on 3 years' outcome for heroin dependence: findings from the Australian Treatment Outcome Study (ATOS). Addiction. 2008;103(1):80–8. Rawson RA, Marinelli-Casey P, Anglin MD, Dickow A, Frazier Y, Gallagher C, et al. A multi‐site comparison of psychosocial approaches for the treatment of methamphetamine dependence. Addiction. 2004;99(6):708–17. King J, Dow J, Stevenson B. Measuring outcomes for TC clients: higher ground drug rehabilitation trust. Therapeutic Communities: Int J Ther Communities. 2016. Wilkins C, Prasad J, Wong K, Rychert M. Recent trends in illegal drug use in New Zealand, 2006–2014: Findings from the 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 illicit drug monitoring system (IDMS). Social and Health Outcomes Research and Evaluation, College of Health, Massey University; 2015. Gossop M, Darke S, Griffiths P, Hando J, Powis B, Hall W, et al. The Severity of Dependence Scale (SDS): psychometric properties of the SDS in English and Australian samples of heroin, cocaine and amphetamine users. Addiction. 1995;90(5):607–14. Sheehan DV, Lecrubier Y, Sheehan KH, Amorim P, Janavs J, Weiller E et al. The Mini-International Neuropsychiatric Interview (MINI): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry. 1998. McLellan A, Cacciola J, Zanis D. The addiction severity index-lite. Center for the Studies on Addiction, University of Pennsylvania/Philadelphia VA Medical Center; 1997. Walji A, Romano I, Levitt E, Sousa S, Rush B, MacKillop J, et al. Psychometric evaluation of the treatment entry questionnaire to assess extrinsic motivation for inpatient addiction treatment. Drug Alcohol Depend. 2022;2:100014. Ustun B, Adler LA, Rudin C, Faraone SV, Spencer TJ, Berglund P, et al. The World Health Organization adult attention-deficit/hyperactivity disorder self-report screening scale for DSM-5. JAMA Psychiatry. 2017;74(5):520–6. Darke S, Hall W, Wodaki A, Heather N, Ward J. Development and validation of a multidimensional instrument for assessing outcome of treatment among opiate users: the Opiate Treatment Index. Br J Addict. 1992;87(5):733–42. Jablensky A, McGrath J, Herrman H, Castle D, Gureje O, Evans M, et al. Psychotic disorders in urban areas: an overview of the Study on Low Prevalence Disorders. Aust NZ J Psychiatry. 2000;34(2):221–36. Lukoff D, Nuechterlein K, Ventura J. Manual for the expanded brief psychiatric rating scale. Schizophr Bull. 1986;12:594–602. Kessler RC, Barker PR, Colpe LJ, Epstein JF, Gfroerer JC, Hiripi E, et al. Screening for serious mental illness in the general population. Arch Gen Psychiatry. 2003;60(2):184–9. Topp L, Mattick RP. Choosing a cut-off on the Severity of Dependence Scale (SDS) for amphetamine users. Addiction. 1997;92(7):839–45. Sobell L, Sobell M, Buchan G, Cleland P, Fedoroff I, Leo G et al. Timeline followback method (drugs, cigarettes, and marijuana). In 30th Annual Meeting of the Association for Advancement of Behavior Therapy1996 Nov 21. Dolan P. Modeling valuations for EuroQol health states. Medical care. 1997:1095 – 108. Mclachlan A. Whāngaihia te hua o oranga ki ō tatou whānau whānui: Ko te tikanga o te whakamahinga o Hua Oranga. Wellington: Te Rau Ora; 2022. Joe GW, Simpson DD, Broome KMJD. Retention and patient engagement models for different treatment modalities in DATOS. Drug Alcohol Depend. 1999;57(2):113–25. Austin PC, Stuart EA. Moving towards best practice when using inverse probability of treatment weighting (IPTW) using the propensity score to estimate causal treatment effects in observational studies. Stat Med. 2015;34(28):3661–79. Berk RA. An introduction to sample selection bias in sociological data. Am Sociol Rev. 1983:386–98. Ciketic S, Hayatbakhsh R, McKetin R, Doran CM, Najman JM. Cost-effectiveness of counselling as a treatment option for methamphetamine dependence. J Subst Use. 2015;20(4):239–46. Husereau D, Drummond M, Petrou S, Carswell C, Moher D, Greenberg D, et al. Consolidated health economic evaluation reporting standards (CHEERS) statement. Cost Eff Resource Allocation. 2013;11(1):6. Manca A, Hawkins N, Sculpher MJ. Estimating mean QALYs in trial-based cost‐effectiveness analysis: the importance of controlling for baseline utility. Health Econ. 2005;14(5):487–96. Tuthill EL, Maltby AE, DiClemente K, Pellowski JA. Longitudinal qualitative methods in health behavior and nursing research: assumptions, design, analysis and lessons learned. Int J Qual Methods. 2020;19:1609406920965799. Calman L, Brunton L, Molassiotis A. Developing longitudinal qualitative designs: lessons learned and recommendations for health services research. BMC Med Res Methodol. 2013;13(1):14. Audulv Å, Hall EO, Kneck Å, Westergren T, Fegran L, Pedersen MK, et al. Qualitative longitudinal research in health research: a method study. BMC Med Res Methodol. 2022;22(1):255. Neale J. Iterative categorization (IC): a systematic technique for analysing qualitative data. Addiction. 2016;111(6):1096–106. Von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet. 2007;370(9596):1453–7. International Committee of Medical Journal Editors. Defining the Role of Authors and Contributors: International Committee of Medical Journal Editors; [cited 2025 12/03/2025]. Available from: https://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6256539","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Study protocol","associatedPublications":[],"authors":[{"id":431244695,"identity":"a3f5a16a-6ca3-4afd-8bdb-8216182b14b3","order_by":0,"name":"David A.L Newcombe","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIiWNgGAWjYDCCA1DagIEZxEyQAbOJ1MKWANLCQ4oWHgPitPAd4D34mKfGJtqcvefjZ56aNB7+2c0bGH7UMOTJN2DXInmAL9mY51ha7s6es5uleY7l8EjcOVbA2HOMoZgRhxaDAzxm0rkNh3M33MjdIM3bUMHDcCPHgIG3gSGxGYfDgFrMf4O13H/z+DdIizxQC+NfoJY23FrMmCG28LABbcnhMQBqYQbZ0oNDi+RhHmPpP2C/pJlZzjmWxmN4I63gsMwxicQZuELseI/hxxk1Nrnb2Q8/vvGmJllO7kbyxodvamwS5+PwPgMzNsEDDAwSONSPglEwCkbBKCAGAABVKVsSp0BrlAAAAABJRU5ErkJggg==","orcid":"","institution":"University of Auckland","correspondingAuthor":true,"prefix":"","firstName":"David","middleName":"A.L","lastName":"Newcombe","suffix":""},{"id":431244698,"identity":"a479a5c9-3b3e-405c-8596-a8619d13e90e","order_by":1,"name":"Sophia de Fossard","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Sophia","middleName":"","lastName":"de Fossard","suffix":""},{"id":431244701,"identity":"1d3ab0da-e76f-4e55-8ff5-df2d8c02d6a3","order_by":2,"name":"Rebecca McKetin","email":"","orcid":"","institution":"University of New South Wales","correspondingAuthor":false,"prefix":"","firstName":"Rebecca","middleName":"","lastName":"McKetin","suffix":""},{"id":431244704,"identity":"e4702db7-443c-4262-b42d-bf3b9006759c","order_by":3,"name":"Vili Nosa","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Vili","middleName":"","lastName":"Nosa","suffix":""},{"id":431244708,"identity":"c9fe2ea5-68d9-4f96-b9fd-84997c6ce231","order_by":4,"name":"Varsha Parag","email":"","orcid":"","institution":"National Institute for Health Innovation, University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Varsha","middleName":"","lastName":"Parag","suffix":""},{"id":431244711,"identity":"bc581e10-9d6e-4046-8d68-13376c946211","order_by":5,"name":"Te Rōpu Poa","email":"","orcid":"","institution":"Ministry of Māori Development","correspondingAuthor":false,"prefix":"","firstName":"Te","middleName":"Rōpu","lastName":"Poa","suffix":""},{"id":431244712,"identity":"13143b5a-39b8-4998-a53c-82d6cee99639","order_by":6,"name":"Rodrigo Ramalho","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Rodrigo","middleName":"","lastName":"Ramalho","suffix":""},{"id":431244714,"identity":"78f8cb2f-21f4-46af-b0f9-e2f83416323b","order_by":7,"name":"Braden Te Ao","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Braden","middleName":"Te","lastName":"Ao","suffix":""},{"id":431244716,"identity":"af5e64fd-f632-48c5-9621-d297ab124d92","order_by":8,"name":"Janie Sheridan","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Janie","middleName":"","lastName":"Sheridan","suffix":""},{"id":431244719,"identity":"525913be-c335-403b-9899-1d5158aa506b","order_by":9,"name":"Carina Walters","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Carina","middleName":"","lastName":"Walters","suffix":""},{"id":431244721,"identity":"0d78ea06-bb8d-4740-8b45-e1cbaf33315d","order_by":10,"name":"Natalie Walker","email":"","orcid":"","institution":"University of Auckland","correspondingAuthor":false,"prefix":"","firstName":"Natalie","middleName":"","lastName":"Walker","suffix":""}],"badges":[],"createdAt":"2025-03-18 23:08:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6256539/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6256539/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":78888408,"identity":"703596fd-a326-49a1-8b99-3e7dd301946d","added_by":"auto","created_at":"2025-03-20 10:01:56","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":46299,"visible":true,"origin":"","legend":"\u003cp\u003eTū Whakaruruhau enrolment pathway [TG = Treatment-Group; NTG = Non-treatment Group]. NB: participants in the Longitudinal Qualitative Study will be recruited from those who have already volunteered to participate in the Longitudinal Cohort Study\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6256539/v1/781aef37888c4eba8bbb4a07.png"},{"id":78939885,"identity":"fb82860d-34f8-4988-8d68-d499b0b990d6","added_by":"auto","created_at":"2025-03-21 06:24:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1108053,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6256539/v1/e308e93a-9b64-4680-b479-f23c9ae21aa7.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Tū Whakaruruhau: The evaluation of treatment outcomes for methamphetamine dependence in Aotearoa New Zealand – study protocol for a prospective longitudinal cohort study and longitudinal qualitative study","fulltext":[{"header":"Background","content":"\u003cp\u003eThe prevalence of amphetamine-type stimulant use (including methamphetamine and amphetamine use) in Aotearoa New Zealand, has remained relatively stable over the last decade. In the 2023/2024 National Health Survey 1.3% (95% Confidence Interval [CI]: 1.0\u0026ndash;1.6) of people aged\u0026thinsp;\u0026ge;\u0026thinsp;15 years of age reported using amphetamine-type stimulants in the past 12-months (56,000 adults nationally) (1). Subgroup analysis by ethnicity (i.e., for Māori, European, and Pacific) indicates no significant difference between groups. However, because methamphetamine use is illegal and highly stigmatized, these survey prevalence estimates are likely to be an underestimate (2). Although the reported prevalence of methamphetamine use is relatively low it is associated with notable public health and social consequences. For example, a 2023 study evaluating and ranking drug harms within New Zealand concluded that methamphetamine was the second most harmful drug (after alcohol) in terms of impact to the overall population (3). In 2016, the total cost of the harms attributable to the use of amphetamine type stimulant in New Zealand, including social costs and the costs of intervention, was estimated at NZ$364.2\u0026nbsp;million (4).\u003c/p\u003e\n\u003cp\u003eMethamphetamine is a potent stimulant that increases monoamine (i.e., dopamine, noradrenaline, serotonin) (5). Methamphetamine\u0026rsquo;s action on dopaminergic pathways in the central nervous system (CNS) is thought to mediate its rewarding properties (i.e., euphoria) which underpin the development of addiction (6). Acute (short-term) effects of methamphetamine intoxication include arousal, euphoria, decreased appetite, behavioural disinhibition, alertness and sympathetic arousal (pupil dilation, increased body temperature, heart rate, blood pressure, and respiratory rate)(5). The negative sequelae of regular/heavy methamphetamine use can include the development of methamphetamine use disorder (MUD), a range of adverse physical (7\u0026ndash;10) and psychiatric effects (11\u0026ndash;14), and negative social outcomes (e.g. relationship breakdown, legal problems and financial problems) (7, 15). A typical pattern of use includes frequent, or binge use, over several days followed by an acute \u0026lsquo;crash\u0026rsquo; phase of one to three days, although daily use is commonly observed in people who experience MUD. In this context, the crash phase is followed by a more prolonged withdrawal phase characterized by fatigue, appetite and mood disturbances, paranoia and drug craving. These withdrawal symptoms can result in people taking another dose of methamphetamine to relieve the symptoms of withdrawal (5).\u003c/p\u003e\n\u003cp\u003eGiven the adverse health and social risks associated with MUD, for many users there will be a desire and/or need to access treatment. There are currently no approved pharmacotherapies for MUD (16, 17). Psychosocial interventions that utilize aspects of cognitive behavioural therapy (CBT), contingency management, and motivational interviewing have been shown to be effective in reducing methamphetamine use in randomised controlled trials when compared to providing no treatment (18, 19). A recent systematic review of clinical trials has revealed the greater effect of contingency management, compared to CBT alone, or contingency management plus CBT, in promoting abstinence and reducing methamphetamine use (19). However, relapse back to methamphetamine use following treatment is common, with data from studies showing that up to 61% of clients relapse within the first year out of treatment, and only 13\u0026ndash;14% remain abstinent after five years (20, 21).\u003c/p\u003e\n\u003cp\u003eTreatment outcome studies are useful for evaluating the effectiveness of treatment for drug dependence as they have greater external validity than clinical trials and can determine what factors are predictive of good outcomes in real-world settings. However, existing treatment outcome studies have mainly focused on people who have alcohol use or heroin use disorder (22\u0026ndash;25), and so their results are not generalisable to people who use methamphetamine. The United States Methamphetamine Treatment project (26) evaluated the Matrix model of treatment (an intensive outpatient treatment programme), compared to treatment as usual (out-patient counselling). The latter improved retention and reduced drug use, but improvements were not sustained following discharge (26). However, these results are not directly relevant to understanding the effectiveness of drug treatment in New Zealand, as the trial only examined psychosocial treatment delivered in US outpatient settings, when much of the drug treatment delivered in New Zealand is via residential treatment (27). Further, this study did not include a non-treatment arm (i.e. control group), making it difficult to conclude that methamphetamine use would not have remitted regardless of the intervention.\u003c/p\u003e\n\u003cp\u003eThe Australian Methamphetamine Treatment Evaluation Study (MATES) was a three-year longitudinal, prospective cohort study that examined treatment outcomes for people with MUD entering residential treatment (n\u0026thinsp;=\u0026thinsp;248) or detoxification (n\u0026thinsp;=\u0026thinsp;112) in Sydney and Brisbane, Australia. (20). The study included a quasi-control group of people who used methamphetamine in the community (n\u0026thinsp;=\u0026thinsp;101). Participants were followed up at three months, one- and three-years after their baseline assessment. There were marked reductions in all measures of methamphetamine use for all groups over the study period. Relative to the control group, detoxification did not reduce methamphetamine use at any follow-up, but residential treatment significantly reduced methamphetamine use at all follow-ups (3-months: Odds Ratio (OR) 0.20, 95% CI: 0.13\u0026ndash;0.33, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001; 1 year: OR 0.58; 95% CI 0.36\u0026ndash;0.95: 3 years: OR 0.57, 95% CI 0.33\u0026ndash;0.99, p\u0026thinsp;=\u0026thinsp;0.0045). Improvements were also seen in other health outcomes (e.g., psychotic symptoms, hostility, anxiety disorders, crime, and human immunodeficiency virus (HIV) risk-taking behaviour. However, these results are not generalisable to New Zealand given its unique cultural and drug-using context - that is, in New Zealand frequent methamphetamine users are less likely to use methamphetamine intravenously than their counterparts in Australia (53% vs 86% respectively) (28). Furthermore, New Zealand has a substantial Māori population, who are the indigenous people of New Zealand, and so the Australian treatment experience cannot inform the nature of treatment responses needed for this population.\u003c/p\u003e\n\u003cp\u003eThere are limited New Zealand data published on the treatment effectiveness for people who access treatment for MUD. A New Zealand evaluation of treatment outcomes in clients discharged after 18 weeks of residential treatment for methamphetamine use found that many reported being abstinent at 3-months (81/86 clients), 6-months (59/64 clients), 9-months (46/50 clients), and at 12-months (34/39 clients) (27). The evaluation also noted reductions in the severity of psychological disorders evident on discharge remained stable during this time (27). However, the generalisability of the latter results to the wider New Zealand context is severely limited due to 1) the lack of a control group and failure to correct for loss-to-follow up; 2) the examination of limited health outcomes; and 3) the focus on residential treatment only. There is also a dearth of literature on the treatment outcomes for Māori who have MUD. Therefore, to address the need for a comprehensive evaluation of treatment effectiveness for MUD in New Zealand we designed a mixed methods programme of research (called Tū Whakaruruhau \u003csup\u003e1\u003c/sup\u003e) that incorporates two studies: one a 24-month prospective longitudinal cohort study (based on MATES) and the other a 12-month longitudinal qualitative study.\u003c/p\u003e\n\u003ch3\u003eObjective\u003c/h3\u003e\n\u003cp\u003eThe primary aim of Tū Whakaruruhau is to elucidate what treatment approaches (specifically, medically managed detoxification, inpatient residential rehabilitation and outpatient counselling/ behavioural support) are effective in managing MUD, and related physical and psychological harms, in New Zealand. The qualitative study will enable collection of information from a subset of methamphetamine users in treatment on their perspectives of what aspects of treatment worked for them. The secondary aim of Tū Whakaruruhau is to explore the relationship between treatment exposure and psychiatric co-morbidity, general wellbeing, health utilization, and criminal involvement, and particularly what client and treatment characteristics predict methamphetamine abstinence.\u003c/p\u003e"},{"header":"Methods","content":"\u003ch2\u003eConsultation\u003c/h2\u003e\n\u003cp\u003eConsultation with treatment providers and those with lived experience of using methamphetamine was undertaken prior to the submission of the funding application. Following funding approval, significant time was spent developing and maintaining relationships with treatment providers), organisations that support and advocate for people with lived and living experience and government ministries and workforce development organizations.\u003c/p\u003e\n\u003cp\u003eThe core research team includes researchers with expertise in addiction and mental health, public health, study design and data analysis, Māori and Pacific Health and lived experience. The research is supported by a Māori Kaitiaki (Māori advisory group), a stakeholder advisory group, and a consumer advisory group. Throughout the study, consultation with these advisory groups will be undertaken to ensure that the study is conducted in a culturally appropriate and safe manner.\u003c/p\u003e\n\u003ch3\u003eStudy 1: Longitudinal Cohort Study\u003c/h3\u003e\n\u003ch2\u003eDesign\u003c/h2\u003e\n\u003cp\u003eThe study design is a prospective longitudinal cohort study. Two groups of people (Treatment Group, Non treatment Group) who report methamphetamine as their primary drug of concern will be recruited and followed-up for up to 24-months: The Treatment Group will include those who at baseline are enrolled in a formal treatment programme for their methamphetamine use; The Non treatment Group will be a comparison group (i.e., quasi-control group) and will include those who at baseline are not enrolled in any formal treatment. Data will be obtained from participants via face-to-face or video (Zoom) interviews at baseline, then at 3-, 12-, and 24-months post baseline.\u003c/p\u003e\n\u003ch3\u003eParticipants\u003c/h3\u003e\n\u003cp\u003eA total of 320 individuals residing in New Zealand will be recruited. Eligible participants are those aged 18 years and over, who use methamphetamine and report that methamphetamine is their main drug of concern, can provide written consent, live in the Northland or greater Auckland/Hamilton regions of New Zealand, have access to a phone, are willing to provide contact details to facilitate follow-up, and are willing to provide follow-up information at scheduled time points. The Treatment Group includes individuals who are enrolled in a formal treatment programme (medically managed detoxification from methamphetamine, or residential treatment, or outpatient counselling/behavioural support) at the time of the screening interview. The Non treatment Group will include individuals who at the time of entry to the study are not in formal treatment for their substance use, but can be attending peer support groups, including narcotic anonymous, and support groups providing harm reduction advice. Furthermore, individuals in the Non treatment Group will need to score ≥ 4 on the Severity of Dependence Scale (SDS) (29) to ensure that their severity level of MUD is comparable to individuals in the Treatment Group. Individuals will be excluded if they have received any formal treatment for any substance use (as an inpatient or outpatient) or were imprisoned in the 30 days prior to either entering treatment (if being considered for the Treatment Group) or 30 days prior to the screening interview (if being considered in the Non treatment Group).\u003c/p\u003e\n\u003cp\u003eSetting and Recruitment\u003c/p\u003e\n\u003cp\u003eThe study will be conducted in the top half of the North Island of New Zealand. Participants in the Treatment Group will be recruited from treatment services, both government-funded and non-governmental organisations, that provide mental health and addiction treatment. Recruitment will be facilitated using flyers placed on noticeboards, recruitment boxes (where those who are interested in participating in the study can provide their contact details), and treatment staff (clinicians) giving out flyers to prospective/interested participants. Participants in the Non treatment Group will be recruited from the general community (via study flyers at support group meetings, community libraries, needle-syringe exchanges, outreach services, and social housing sites). General methods to recruit individuals for both the Treatment and Non treatment Group will include media advertising, peer referral and promotion through local networks, and agencies and community groups, and peer networks. It is envisaged that recruitment will take place over approximately 20–24 months from the end of October 2023. Interested individuals will be required to make initial contact with a researcher (via phone, text message, or email) to indicate their interest in participating in the study.\u003c/p\u003e\n\u003ch2\u003eStudy procedures\u003c/h2\u003e\n\u003cp\u003eFigure 1. shows the procedures for the study. Interested participants will be contacted by a researcher who will screen them for eligibility. If the individual is eligible, the researcher will organise to meet the participant to complete the screening/consent process. Participants will be provided a copy of the participant information sheet that summarises what participation in the study means and that they can provide consent or decline when the participant meets the researcher at the first face-to-face meeting. Once written consent is obtained, baseline data will be collected. At this first meeting, the participants’ contact details, and the contact details of two other people they know, will be collected and used to facilitate follow-up. In appreciation of their time, a koha (gift) of NZ$120 will be provided to each participant in the form of grocery vouchers. The koha will be divided into four equal amounts of NZ$30.\u003c/p\u003e\n\u003cp\u003eFollow-up interviews will occur at 3–, 12-, and 24-months post baseline interview. Participants will be contacted by a member of the research team at the scheduled times using the contact details provided (i.e., by text if a mobile phone number has been provided, or email message). Initially a maximum of two attempts will be made to contact the participant, using the personal contact information provided. If this initial attempt to contact the participant is not successful then the research assistant will attempt to contact the participants' designated contact person. A maximum of two attempts will be made to contact the participants' designated contact person - if this fails the participant will be considered lost to follow-up.\u003c/p\u003e\n\u003cp\u003eData collection will be undertaken by graduate research assistants who have undertaken two weeks of intensive training prior to commencing interviewing. The training curriculum will cover material relevant to conducting research interviews of this type (including engagement and safety), cultural safety, psychiatric diagnoses, and administration of the battery of questionnaires (see Table 1). All training will be conducted by investigators who are health professionals and have qualifications/experience in addictions and mental health and counselling. Prior to commencing the research interviews, research assistants will be required to conduct role plays with professional actors to demonstrate their competence (particularly cultural competency), and fidelity to the guidelines for administration of the questionnaire battery. All data collection (with the exception of questions that make up The Mini International Neuropsychiatric Interview (M.I.N.I) (30), in order to adhere to the licencing agreement), will be collected and managed using REDCap (Research Electronic Data Capture).\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv\u003eTable 1\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eSchedule of baseline and follow-up assessments for longitudinal cohort study.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth rowspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eTimepoint\u003c/p\u003e\n \u003c/th\u003e\n \u003cth rowspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eScreen\u003c/p\u003e\n \u003c/th\u003e\n \u003cth colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eInterviews\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eBaseline\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e3mth\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e12mth\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e24mth\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEligibility Screening\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eInformed consent\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eContact information\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" align=\"left\"\u003e\n \u003cp\u003eAssessments:\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" align=\"left\"\u003e\n \u003cp\u003eDescriptives\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDemographics: Age, gender, ethnicity, iwi, education\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGeneral: living situation, employment status, prison history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment and substance use history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDrug using history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" align=\"left\"\u003e\n \u003cp\u003ePrimary outcome\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMethamphetamine use /abstinence last month [Q score]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" align=\"left\"\u003e\n \u003cp\u003eSecondary outcome measures\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-treatment motivation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCurrent drug use – other than methamphetamine [Q score]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDays methamphetamine used in last month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDSM-5 diagnosis of methamphetamine (stimulant) use disorder\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLevel of methamphetamine dependence [(SDS]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDSM-5 diagnosis of psychiatric co morbidity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSeverity of psychiatric symptoms [Psychosis screen]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSeverity of psychological distress\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBlood borne risk behaviour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment experience\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCriminal involvement\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHealth service utilization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHealth-related quality of life\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGeneral wellbeing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRapport/engagement with treatment staff [Index Treatment]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment modality/treatment characteristics [Index Treatment]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment exposure (treatment received)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e✓\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003ch3\u003eData sources/ measurement\u003c/h3\u003e\n\u003cp\u003eThe following general information will be collected at each timepoint: Employment status, living arrangement (alone, with partner, children, parents, non-related adults), income (net income past fortnight), accommodation (public housing, privately owned, parents’ home, boarding house/shelter, drug treatment, non-fixed address), prison history, motives for attending treatment (legal reasons, to maintain/regain custody of children), locator information (physical address, phone number of participant and contact details of at least two acquaintances), and whether deceased (post-baseline).\u003c/p\u003e\n\u003cp\u003eThe following baseline variables will be collected (Table 1).\u0026nbsp;\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eDemographic information\u003c/em\u003e: date of birth, gender, ethnicity, socio-economic position (based on highest level of education attained) detail will be collected. Those selecting Māori descent will be able to state their iwi/hapu (tribe/subtribes) and to indicate their connectedness to their iwi (Measured on a Likert scale: 1 = not very much to 5 = very much).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eDrug using history\u003c/em\u003e: Assessed using a modified version of the Addiction Severity Index-lite (31) to determine what drugs have been used in the participants lifetime.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eAddiction treatment history\u003c/em\u003e: Participants will be asked about the number and types of drug treatment they have started, not just for methamphetamine but also other psychoactive substances.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eMotivation to enter treatment for methamphetamine use [Treatment Group participants only]\u003c/em\u003e: Measured using the Treatment Entry Questionnaire (TEQ-9) (32).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003ePsychiatric co-morbidity\u003c/em\u003e: The DSM-5 current/past psychiatric diagnoses (major depressive episode, manic or hypomanic episode, bipolar disorder, panic disorder, agoraphobia, social anxiety disorder, generalised anxiety disorder, PTSD, assessed using the M.I.N.I (30).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eSelf-report DSM-5 Attention Deficit Hyperactivity Disorder [ADHD]\u003c/em\u003e: Measured using the Adult ADHD Self-Report Scale for DSM5 (ASRS-5) (33).\u003c/p\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cem\u003ePrimary outcome:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe primary outcome measure is self-reported methamphetamine use (days used last month) at 12-months provided by the Drug Use Section of the Opiate Treatment Index (OTI) in the form of the Q score. The Q score is a quantitative estimate of drug use quantity/frequency which is determined through the addition of consumption amounts on two previous days and dividing this value by the time intervals between these days during the preceding month (34). While the Q score is a continuous variable it will be considered a binary outcome in analyses: No use (abstinence): Use.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eSecondary outcome measures:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eSecondary outcomes will be assessed at baseline then at three, 12- and 24-months post baseline (Table 1).\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eSymptoms of Psychosis\u003c/em\u003e: Measured using a screen for the presence of psychotic symptoms at each assessment (35). This screen will also include an item from the Brief Psychiatric Rating Scale that assesses hostility (36).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eSeverity of Psychological Distress\u003c/em\u003e: Measured using the Kessler Psychological Distress Scale (K10) (37), at each assessment (max score = 50). The Kessler provides a global measure of psychological distress in the last month. Scores \u0026gt; 30 will be used as an indicator of severe distress, and interviewers will be required to follow the participants safety protocol outlined in the Study Fieldwork Safety Manual.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eDSM-5 diagnosis of stimulant (methamphetamine) use disorder\u003c/em\u003e Assessed using the M.I.N.I (30) at baseline,12, and 24-months only.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eSeverity of stimulant (methamphetamine) dependence\u003c/em\u003e: Measured by the SDS (29) which contains five items (maximum score = 15) that assess the psychological components of dependence (impaired control, preoccupation, anxiety over drug use), and will provide a continuous measure that will help differentiate the severity of methamphetamine dependence. A cut-off score of ≥ 4 indicates methamphetamine dependence (38).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eMethamphetamine use\u003c/em\u003e: Assessed using two methods at each assessment: 1) The drug use section of the OTI will be used to determine the Q score for methamphetamine use (34); 2) The Time-line-Follow-Back (TLFB) to measure the frequency of methamphetamine use in the past 4 weeks (39). Continuous methamphetamine abstinence will be defined as no use of methamphetamine since baseline (20).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eCurrent general drug use (opiates, benzodiazepines, cannabis) use\u003c/em\u003e: Measured using the drug use section of the OTI, to determine the Q score for each drug of interest (29).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eHealth-related quality of life (HRQoL)\u003c/em\u003e: Measured using the EuroQol- EQ-5D-five level version (EQ-5D-5L)(40), which assesses mobility, self-care, usual activities, pain/discomfort, anxiety/depression on three levels (no problems, some problems, extreme problems)\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eBlood Borne Virus risk taking behaviour\u003c/em\u003e: Assessed using a modified version of the HIV risk taking behaviour scale [HRBS] of the OTI (34) (McKetin, personal communication).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eCriminal involvement\u003c/em\u003e: Assessed using the crime scale of the OTI (34) .\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eHealth Service Utilisation (HSU)\u003c/em\u003e: Measured using the HSU form (Centre for Health Economics Research and Evaluation, University of Sydney).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eGeneral wellbeing\u003c/em\u003e: Measured using the Hua Oranga outcome questionnaire – this is a Māori measure of mental health outcome developed through the application of Te Whare Tapa Wha (Holistic approach to assess wellbeing) (41).\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003e\u003cem\u003eRapport with treatment staff\u003c/em\u003e: Measured using a scale that assesses staff support of patient goals; staff sincerity; ability to work with staff; treatment matched expectations; each item scored 1 to 4 to produce scores from 5 to 20 with higher scores indicating greater support (42).\u003c/p\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003ch2\u003eDescriptive measures\u003c/h2\u003e\n\u003cp\u003eTable 2 provides a definition of each treatment modality (residential treatment, medical detoxification and outpatient counselling) and the measures/methods used to describe the characteristics of treatment and assessment of treatment duration.\u0026nbsp;\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv\u003eTable 2\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eDescription of the modality of the treatment, characteristics of the treatment agencies and treatment experienced by participants\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDefinition of modality of treatment\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristics of the treatment agencies and of the index treatment.\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTreatment exposure (Amount of treatment)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline/Index treatment\u003c/strong\u003e: Will be defined as contiguous treatment (\u0026lt; 8 days gap between treatment episodes to allow for transfer between services) from intake to leaving treatment.\u003c/p\u003e\n \u003cp\u003eThe modality of treatment will be based on the main form of treatment provided during the baseline treatment episode and will be defined as either;\u003c/p\u003e\n \u003cp\u003e1) \u003cem\u003edetoxification\u003c/em\u003e (usually brief, one week) inpatient/ outpatient withdrawal management with or without the use of medications), or;\u003c/p\u003e\n \u003cp\u003e2) \u003cem\u003eresidential rehabilitation\u003c/em\u003e that involves longer stays at residential settings that provide intensive therapeutic programmes, or;\u003c/p\u003e\n \u003cp\u003e3) o\u003cem\u003eutpatient counselling\u003c/em\u003e where clients attend addiction services regularly for weeks or months to individual counselling sessions or group sessions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristics of the treatment service\u003c/strong\u003e, including:\u003c/p\u003e\n \u003cp\u003e• staff numbers,\u003c/p\u003e\n \u003cp\u003e• staff to client ratio,\u003c/p\u003e\n \u003cp\u003e• staff training (qualifications (discipline, experience in working in the mental health and addiction sector),\u003c/p\u003e\n \u003cp\u003e• on site-training and supervision of staff.\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristics of the treatment\u003c/strong\u003e, including:\u003c/p\u003e\n \u003cp\u003e• whether the treatment includes a follow-up program and whether the participant completes this, and;\u003c/p\u003e\n \u003cp\u003e• whether they receive any medication during admission (antidepressants, antipsychotics, benzodiazepines etc).\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eTreatment exposure: Indicators will include\u003c/strong\u003e;\u003c/p\u003e\n \u003cp\u003e• number of counselling sessions (group \u0026amp; individual) completed (drug focused vs other issues considered)\u003c/p\u003e\n \u003cp\u003e• completed days of treatment, total duration of treatment (from start to finish date).\u003c/p\u003e\n \u003cp\u003eCollected at each assessment (for all participants);\u003c/p\u003e\n \u003cp\u003e• \u003cem\u003eDuration of treatment\u003c/em\u003e: Days of contiguous treatment (\u0026lt; 8 days gap) from intake to leaving treatment (including days spent in a detoxification unit (if required for admission to the baseline treatment).\u003c/p\u003e\n \u003cp\u003e• \u003cem\u003eTreatment re-entry\u003c/em\u003e: At each interview, participants will be asked how many treatment episodes they started since their last interview. The details of each episode will be described (modality, duration, completion) and whether they received treatment for methamphetamine\u003c/p\u003e\n \u003cp\u003e• \u003cem\u003eTreatment retention and completion: This is a dichotomous measure indicating having stayed in treatment (or not) for at least the median number of days for the baseline treatment modality (35 days for outpatient counselling, 19 days for residential rehabilitation, 5 days for detoxification). Treatment completion will be based on the participants’ self-report.\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003ch2\u003eStudy size\u003c/h2\u003e\n\u003cp\u003eTwo sample sizes have been calculated based on two rates of attrition, i.e., 20% and 30%, that will inform our recruitment processes. The first sample size is adjusted for 20% attrition and requires 320 participants (3:1 ratio: 240 in the Treatment Group, 80 in the Non treatment Group), the second requires 367 participants (3:1 ratio: 275 in the Treatment Group, 92 in the Non treatment group) to provide 90% power at p = 0.05 (2-sided alpha) to detect an absolute difference between the two groups of 20% in the proportion of participants at 12-months that have not used methamphetamine in the past month (assuming 40% in the Treatment Group and 20% in the Non treatment Group) based on findings from the MATES study (20). Equal numbers of participants in the Treatment Group will be sought from residential, detoxification and outpatient treatment settings, and at least 50% self-identifying as Māori across the whole study.\u003c/p\u003e\n\u003ch2\u003eData Analyses\u003c/h2\u003e\n\u003cp\u003eAll statistical analyses will be performed using SAS version 9.4 (SAS Institute Inc. Cary NC). Data analyses will be specified a priori in a statistical analysis plan prepared by the study statistician (VP). No interim analyses are planned.\u003c/p\u003e\n\u003cp\u003eAll baseline data will be summarised by treatment group. Treatment evaluations for the primary outcome will be carried out an intention-to-treat basis, with multiple imputation analysis used to account for missing data. Binary outcomes will be analysed using log-binomial regression analysis. The main analyses for the primary outcome will be adjusted for demographics (gender, ethnicity, age) psychiatric co-morbidity, polydrug use, baseline methamphetamine use disorder, treatment history and treatment re-entry during follow-up and any important imbalances in baseline covariates. To assess the robustness of the primary outcome various sensitivity analyses will also be conducted, including using the actual treatment the participant received during the follow-up rather than the index (baseline) treatment group, and assessing the impact of missing data such as complete case analysis. Repeated measures analysis will be used to assess change over time.\u003c/p\u003e\n\u003cp\u003eTo determine predictors of the outcomes (such as demographics, treatment exposure, and psychiatric diagnosis) multiple linear or log-binomial regression will be used as appropriate. The consistency of effects for prescribed subgroups (Māori status, age and sex) will be assessed using tests for heterogeneity. In order to eliminate any association between the treatment grouping and factors that predict treatment grouping the Inverse Probability of Treatment Weighted estimates of treatment outcomes derived by weighting the samples with the inverse of the ‘propensity to treat’ score will be used (20, 43).\u003c/p\u003e\n\u003cp\u003eThe impact of differential sample attrition (i.e., there may be differences in those not successfully followed up to those located and interviewed) will be corrected using the methods of Berk (1983) (44). The main predictor variable will be treatment exposure (indicated by retention in treatment, treatment completion, and dose (days) of treatment received). Covariates will include demographics (age, gender, employment status), psychiatric comorbidity, polydrug use, and dependence on MA at baseline.\u003c/p\u003e\n\u003cp\u003eMissing data will be managed according to the following steps: 1) Follow-up of all individuals will be attempted, using all the contact information collected at consent. As the data is captured electronically the research assistants will be able to view who has completed, who has not, and what set of reminder notifications need to be sent; 2) For data collection time points 3-, 12-, and 24- months a two-week timeframe will be allowed for each follow-up assessment and so response intervals and frequency of questionnaire completion will be expected to vary between individuals. The two-week period post due date was selected as reasonable, as all participants will receive a notification one week before each data collection time point to organise a time to meet with the research assistant to complete the interview battery, and 3) If a participant misses a timeframe to contribute to a specific data point, it does not preclude them from completing the next data evaluation point when that falls due.\u003c/p\u003e\n\u003ch2\u003eHealth economic evaluation\u003c/h2\u003e\n\u003cp\u003eCost outcomes will include estimates of the costs of intervention (e.g., assessment), and treatment (e.g., counselling, residential treatment, detoxification) for methamphetamine use and health service utilisation costs (visit to emergency department, health practitioner visits, other health service utilisation costs and specific medications). Self-reported service use will be supplemented by electronic administrative data (i.e., the National Minimum Data Set for hospital admissions) obtained with consent. Using a resource-based costing approach that measures the inputs required to deliver a service (e.g., identify provision of care/number of visits) and applying market prices to each of these resources (e.g., cost/hour for healthcare visit). Unit costs will be sourced from published New Zealand data (where available), and where they are unavailable, published international data (once its applicability to New Zealand’s context is thoroughly assessed) or local estimates. Costs will be measured in 2025/6 New Zealand dollars. In addition, we will estimate the crime costs attributed to four different categories, property crime, dealing, fraud and violent crime (45).\u003c/p\u003e\n\u003cp\u003eCost analysis will include direct health care costs (i.e., healthcare services, prescription charges), indirect costs (cost of crime), and out of pocket expenses associated with the Treatment Group compared with the Non treatment Group. Cost offsets refer to the scenario where costs of crime and health service utilisation play an important role in the cost-reductions (cost-savings) over a period of 2 years. These cost-savings are likely due to overall lower level of crime activity and health service utilisation patterns among participants in the Treatment Group compared with the Non treatment Group. If feasible, a cost-effectiveness analysis will be conducted under the Consolidated Health Economic Evaluation Reporting Guidelines (46) to examine the likely impact of methamphetamine treatment aimed at reducing methamphetamine use and related harms in the New Zealand context. The EQ-5D scores (40) will be transformed into quality-adjusted life years (QALYs) using the ‘area under the curve’ method (47). Methamphetamine use at 12 months (abstinent days last month) will be the clinical benefit measure. An incremental cost-effectiveness ratio will be calculated to compare additional costs and health benefits associated with the Treatment Group compared with the Non treatment Group.\u003c/p\u003e\n\u003cp\u003eFor data linkage, the participants will be asked to consent to data being sought from the Ministry of Health on the number of times they had been admitted to hospital, seen in the emergency department or had an outpatient visit (healthcare utilisation, for example counselling and treatment) from recruitment until 2 years. Similarly, with consent, we will seek information on the number of charges and convictions relating to property crime, dealing fraud and violent crime to estimate the cost of crime attributable to MUD. With consent, the participants’ National Health Index number will be provided to the Ministry of Health for linkage to their healthcare utilisation data. Their inland revenue department number will be provided to the Ministry of Justice for linking with the cost of crime\u003c/p\u003e\n\u003ch2\u003eStudy 2: Longitudinal Qualitative Study\u003c/h2\u003e\n\u003ch2\u003eDesign\u003c/h2\u003e\n\u003cp\u003eA longitudinal qualitative research design will be utilised to explore treatment goals, perceptions of treatment effectiveness, and treatment outcomes. Longitudinal qualitative research has been previously utilised in health research to explore the lived experiences of patients about treatment and change over time (48–50), and will be a valuable addition to the longitudinal cohort study. Each participant enrolled in the Longitudinal Qualitative Study will be asked to attend three interviews across a 12-month period.\u003c/p\u003e\n\u003ch2\u003eParticipants\u003c/h2\u003e\n\u003cp\u003eThirty participants from the Treatment Group of study 1 will be recruited, over 12 months.\u003c/p\u003e\n\u003ch2\u003eSetting\u003c/h2\u003e\n\u003cp\u003eSee Study 1.\u003c/p\u003e\n\u003ch2\u003eSampling\u003c/h2\u003e\n\u003cp\u003eSampling will be purposive. Equal numbers of participants will be recruited from residential, detoxification and outpatient treatment settings, and at least 50% will self-identify as Māori.\u003c/p\u003e\n\u003ch2\u003eRecruitment and follow up\u003c/h2\u003e\n\u003cp\u003eParticipants in Study 1 will be asked whether they consent to participation in the Longitudinal Qualitative Study at the initial baseline interview for the Longitudinal Cohort Study. Purposive sampling will be undertaken from this consented group. The procedures used to follow up participants for the cohort study will be utilised to follow-up participants in the Longitudinal Qualitative Study.\u003c/p\u003e\n\u003ch2\u003eData collection\u003c/h2\u003e\n\u003cp\u003eParticipants will be interviewed at baseline, 6 months and 12 months. To avoid fatigue, the baseline and 12-month Longitudinal Qualitative Study interviews will be carried out at different times from the interviews for the Longitudinal Cohort Study. All interviews will be audio recorded. Participants in the Longitudinal Qualitative Study will receive a gift (koha) of $90 which will be provided to each participant in the form of grocery vouchers ($30 for each interview they attend).\u003c/p\u003e\n\u003cp\u003eData collection will be undertaken by the same research assistants working on the cohort study (Study 1). The research assistants will receive training on undertaking semi-structured, qualitative interviews and will undergo peer review of their practice sessions with trained actors. A particular focus of the training will be the use of prompts to encourage more in-depth discussion of key areas/concepts and probing to encourage more detailed descriptions.\u003c/p\u003e\n\u003ch2\u003eResearch questions\u003c/h2\u003e\n\u003cp\u003eThe questions asked during the interviews will broadly explore participants’ experiences, and expectations of treatment, and treatment outcomes at baseline and follow-up interviews. Baseline questions will explore if anything relevant has happened in the 2 months prior to entering treatment, participants’ reasons for entering treatment, and what participants want to get out of treatment. Further questions will explore if treatment is what they expected, what aspects of treatment are working for them, and if they have any suggestions to improve treatment. At the 6- and 12- months interviews participants will be asked if they are still in treatment, and if they are, why, and if treatment is what they expected. Participants will then be asked what has been working for them. Participants will also be asked if they have any suggestions to improve treatment. If the participants are not in treatment at the time of the interview, they will be asked why they left treatment, and if they have any suggestions to improve treatment. Participants will also be asked about their methamphetamine and other substance use at each interview. Those who have relapsed will be asked what, if any, aspects of treatment have proved helpful in dealing with their MUD and whether they have suggestions to improve this aspect of treatment.\u003c/p\u003e\n\u003ch2\u003eQualitative Data Management and Analysis\u003c/h2\u003e\n\u003cp\u003eAll interviews for the Longitudinal Qualitative Study will be audio recorded and transcribed verbatim by a local professional transcription service and stored in a secure file. To maintain the quality of these interviews the following plan will be followed: after 10 baseline interviews have been completed, each research assistant will listen to one of their interviews, and one other from another research assistant, and reflect on several aspects (including building rapport, use of clarification questions). Research assistants will be required to keep field notes regarding whether the interview was cut short, and why, any significant events in the interview, such as interruptions, and any concerns they may have about participants.\u003c/p\u003e\n\u003cp\u003eAnalysis will be diachronic (after all data collection has been completed) and take a thematic approach with a combination of deductive (explaining findings from the quantitative data) and inductive (allowing new themes to emerge, to identify pathways and change over time (see \u003csup\u003e(48)\u003c/sup\u003e). A deductive coding framework will be developed based on the interview guide and all interviews will be coded by one person. Inductive codes (new codes arising as part of the coding process) will be added later during the coding process. Analysis will be guided by an iterative categorisation technique (51). A combination of cross-sectional baseline analysis, followed by trajectory analysis by wave (baseline, 6- and 12-months) will be undertaken. All Māori data analysis will be undertaken through a Māori lens overseen by the principal Māori investigator (TP) and the Māori governance group.\u003c/p\u003e\n\u003ch2\u003eEthical considerations and dissemination\u003c/h2\u003e\n\u003cp\u003eBoth studies have been approved by the New Zealand Health and Disability Ethics Committee (Ref: 2023 EP 15148) and any changes will be reported as per ethics standard operating procedures and policies. This programme of work is also registered with the Australian and New Zealand Clinical Trial Registry (ACTRN12623000438651p), and the protocol conforms to the STROBE statement (52).\u003c/p\u003e\n\u003cp\u003eA dissemination plan has been drafted and will be updated as the study progresses. Investigators are required to sign this document and indicate their understanding of what constitutes authorship of scientific outputs (according to International Committee of Medical Journal of Editors (ICMJE) Guidelines) (53). Findings will be shared by publication in peer reviewed journals and presentations at local and international conferences. Dissemination of findings will include feedback to participants (via the study website and summaries presented at recruitment sites), national media releases at the time of journal publication and presentations at local, national and international audiences. Bespoke arrangements will be made for local presentations to reflect the different audiences (treatment services, government (Policy and workforce groups, advocacy groups) across New Zealand likely to be interested.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eTū Whakaruruhau will be unique in that it is the first programme of research that promises to provide evidence of the effectiveness of standard approaches (medical detoxification, residential treatment and community approaches) in the treatment of MUD in the New Zealand context. The longitudinal cohort study (Study 1) will provide a clearer understanding of what predicts better, more equitable, and cost-effective health outcomes for people living with MUD in New Zealand. The findings from this work will inform treatment guidelines and relevant evidence reviews. The recruitment of at least 50% of participants who identify as Māori will ensure appropriate representation of the indigenous voice in this study. Further, the addition of a longitudinal qualitative arm (Study 2) to the research programme will provide the opportunity for people living with MUD to say what they believe is working for them and to advocate for the use of intervention/treatment approaches they believe would improve treatment.\u003c/p\u003e \u003cp\u003eThe development of this programme of work has been guided by Māori researchers and practitioners on the study investigator team and a Māori advisory group to ensure that it incorporates a Māori culturally world view (Te Ao Māori). This is to ensure that the rights of Māori, who are the indigenous people of NZ, are upheld.\u003c/p\u003e \u003cp\u003eFindings from Tū Whakaruruhau will inform and provide the basis for the ongoing establishment of an evidence base for treatment for problematic methamphetamine use (including MUD) in Aotearoa New Zealand. This paper reports on the protocol version 1.1, 7th July 2023 and that has ethical approval. The study design has been peer reviewed as part of the funding process. This study is currently ongoing; recruitment started in December 2023. Recruitment will cease July, 2025. The final follow-up is expected in June 2027.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eADHD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAttention Deficit Hyperactivity Disorder\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eASRS-5\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAdult ADHD Self-Report Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCBT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCognitive Behavioural Treatment\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eConfidence Intervals\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCNS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCentral Nervous System\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDSM-5\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDiagnostic Statistical Manual \u0026ndash; 5th Edition\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEQ-5D-5L\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEuroQuol \u0026minus;\u0026thinsp;5D-5L\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHIV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHuman immunodeficiency Virus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHRBS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHIV risk taking behaviour scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHRQuol\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHealth related quality of life\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHSU\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHealth service utilisation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eICMJE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInternational Committee of Medical Journal Editors\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eK10\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eKessler\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMATES\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMethamphetamine Treatment Evaluation Study\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eM.I.N.I\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMini-International Neuropsychiatric Interview\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMUD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMethamphetamine use disorder\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNGO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNon-governmental organization\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOTI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOpiate Treatment Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOdds Ratio\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eQALY\u0026rsquo;s\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eQuality adjusted life years\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eREDCap\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eResearch Electronic Data Capture\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSubstance Dependence Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTEQ-9\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTreatment Entry Questionnaire\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTLB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTimeline Follow Back\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUnited States of America\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis programme of work was approved by the New Zealand Central Health and Disability Ethics Committees (reference: 2023 EP 15148). Ethics approval for any amendments to the study protocol will be sought. \u0026nbsp;Maintenance of confidentiality and compliance with NZ’s Privacy Act will be emphasised to all study participants. Participation in the study will be entirely voluntary. Written consent will be obtained from all participants for both studies prior to enrolling in the study. All data collected for Study 1 will be entered, stored and backed-up in a secure manner via an internet data management system. Qualitative data from study 2 will be initially stored as audio files on a secure password protected site prior to transcription. Transcription will be undertaken by a local transcription company that is ISO9001 and ISO27001 accredited. The transcription company will be required to sign and adhere to a data management agreement. Transcription will be undertaken by transcribers based in New Zealand. Both the recoding and transcription will be securely stored until after the study has finished to allow researchers to check that the transcription was accurate. Once the researchers have finished the analysis the audio recordings will be destroyed. If any participants suffer harm from study participation, they will be eligible for compensation via their private health or life insurance, or via NZ’s Accident Compensation Corporation (ACC) scheme.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo identifiable individual participant data (names or other personal identifiers) are contained in this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets that will be used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo authors have received financial support from any companies for the submitted work. All authors declare that they have no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is funded by a 40-month project grant from the Health Research Council of New Zealand (22/327). The study protocol has undergone peer review by the funding body. Top-up funding is been sought to enable follow-up of all 24-month interviews and more comprehensive data linkage. Funders will not be involved in the design of the study, collection, analysis and interpretation of the data.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAuthorship complies with the ICMJE authorship eligibility guidelines. DN, RM and PA developed the initial overall study design; DN, RM, PA, NW, JS, RR, BTA, VN, VP sought and obtained funding for the study and wrote the study protocol. SdF is the project manager responsible for the day-to-day running of the study. PA and later TP (following the death of PA) lead the Māori Governance group for the study. JS and CW lead study 2. CW will lead the longitudinal qualitative analysis. DN, RR, SF, JS, PA and CW will be involved in training of the research assistants. VP will undertake all data analysis for the longitudinal cohort study. BTA will undertake health economic analyses. All investigators are members of the research steering committee. DN led the preparation of the manuscript. DN is guarantor for this paper. All authors have read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorresponding Author\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence to David Newcombe\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe acknowledge Whaea (Aunty) Pam Armstrong who with DN conceived the original idea for the study and was an investigator on Tū Whakaruruhau\u0026nbsp;until her death in 2024. We wish to acknowledge Auckland Uni-Services staff involved in study management and data management processes, and members of the Māori governance group who provide overarching cultural advice and encouragement – initially under the guidance of Whaea Pam Armstrong, and currently Te Rōpu Poa. We also acknowledge the team of research assistants for their passion, commitment for this project and tenacity in recruiting and following up participants. We also thank members of the consumer advisory committee. We thank all the treatment providers and health professional for their support of, and promotion of this study to people who use methamphetamine, and who make it possible to recruit participants\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors Information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eDepartment of Social and Community Health, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.\u0026nbsp;\u003csup\u003e2\u003c/sup\u003eCentre for Addiction Research, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. \u003csup\u003e3\u003c/sup\u003eNational Institute for Health Innovation, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. \u003csup\u003e4\u003c/sup\u003eNational Drug and Alcohol Research Centre, Randwick Campus, University of New South Wales, NSW 2013, Australia. \u003csup\u003e5\u003c/sup\u003eDepartment of Pacific Health, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.\u003csup\u003e6\u0026nbsp;\u003c/sup\u003eMinistry of Māori Development, 85-87 Cameron Street, Whangarei 0110, New Zealand. \u003csup\u003e7\u003c/sup\u003eDepartment of Health Systems, School of Population Health, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFootnotes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e1. Tū Whakaruruhau is a te reo (Māori language) name gifted by the study Māori advisory committee. Translated the name means ‘to stand as a protection, to be a beacon of manaakitanga (to show respect and care for others)’.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMinistry of Health. Annual Data Explorer 2023/2024: New Zealand Health Survey. Wellington: Ministry of Health.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChan GC, Sun T, Lim C, Stjepanović D, Rutherford B, Johnson B, et al. Did the under-reporting of meth/amphetamine use increase in a general population survey in Australia as negative media coverage increased? Addiction. 2022;117(6):1787\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCrossin R, Cleland L, Wilkins C, Rychert M, Adamson S, Potiki T, et al. The New Zealand drug harms ranking study: A multi-criteria decision analysis. J Psychopharmacol. 2023;37(9):891\u0026ndash;903.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcFadden C. Researh Report: The New Zealand Drug Harm Index 2016. Ministry of Health; 2016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCruickshank CC, Dyer KR. A review of the clinical pharmacology of methamphetamine. Addiction. 2009;104(7):1085\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVolkow ND, Michaelides M, Baler R. The neuroscience of drug reward and addiction. Physiol Rev. 2019;99(4):2115\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDarke S, Kaye S, McKetin R, Duflou J. Major physical and psychological harms of methamphetamine use. Drug Alcohol Rev. 2008;27(3):253\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaye S, McKetin R, Duflou J, Darke S. Methamphetamine and cardiovascular pathology: a review of the evidence. Addiction. 2007;102(8):1204\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTurnipseed SD, Richards JR, Kirk JD, Diercks DB, Amsterdam EA. Frequency of acute coronary syndrome in patients presenting to the emergency department with chest pain after methamphetamine use. J Emerg Med. 2003;24(4):369\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerez JA Jr, Arsura EL, Strategos S. Methamphetamine-related stroke: four cases. J Emerg Med. 1999;17(3):469\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcKetin R, Lubman DI, Baker AL, Dawe S, Ali RL. Dose-related psychotic symptoms in chronic methamphetamine users: evidence from a prospective longitudinal study. JAMA psychiatry. 2013;70(3):319\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eConnell PH. Amphetamine psychosis Maudsley Monographs No5. London: Oxford University Press; 1958.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcKetin R, Dawe S, Burns RA, Hides L, Kavanagh DJ, Teesson M, et al. The profile of psychiatric symptoms exacerbated by methamphetamine use. Drug Alcohol Depend. 2016;161:104\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimon SL, Dean AC, Cordova X, Monterosso JR, London ED. Methamphetamine dependence and neuropsychological functioning: evaluating change during early abstinence. JSAD. 2010;71(3):335\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSommers I, Baskin D, Baskin-Sommers A. Methamphetamine use among young adults: health and social consequences. Addict Behav. 2006;31(8):1469\u0026ndash;76.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharafi H, Bakouni H, McAnulty C, Drouin S, Coronado-Montoya S, Bahremand A, et al. Prescription psychostimulants for the treatment of amphetamine‐type stimulant use disorder: a systematic review and meta‐analysis of randomized placebo‐controlled trials. Addiction. 2024;119(2):211\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFarrell M, Martin NK, Stockings E, B\u0026oacute;rquez A, Cepeda JA, Degenhardt L, et al. Responding to global stimulant use: challenges and opportunities. Lancet. 2019;394(10209):1652\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMinozzi S, Saulle R, De Crescenzo F, Amato L. Psychosocial interventions for psychostimulant misuse. Cochrane Database Syst Reviews. 2016(9).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAshaRani P, Hombali A, Seow E, Ong WJ, Tan JH, Subramaniam MJD, et al. Non-pharmacological interventions for methamphetamine use disorder: a systematic review. Drug Alcohol Depend. 2020;212:108060.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcKetin R, Najman JM, Baker AL, Lubman DI, Dawe S, Ali R, et al. Evaluating the impact of community-based treatment options on methamphetamine use: findings from the Methamphetamine Treatment Evaluation Study (MATES). Addiction. 2012;107(11):1998\u0026ndash;2008.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrecht M-L, Herbeck D. Time to relapse following treatment for methamphetamine use: a long-term perspective on patterns and predictors. Drug Alcohol Depend. 2014;139:18\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHser Y-I, Hoffman V, Grella CE, Anglin MD. A 33-year follow-up of narcotics addicts. Arch Gen Psychiatry. 2001;58(5):503\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHubbard RL, Craddock SG, Anderson J. Overview of 5-year followup outcomes in the drug abuse treatment outcome studies (DATOS). J Subst Abuse Treat. 2003;25(3):125\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGossop M, Marsden J, Stewart D, Kidd T. The National Treatment Outcome Research Study (NTORS): 4\u0026ndash;5 year follow-up results. Addiction. 2003;98(3):291\u0026ndash;303.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeesson M, Mills K, Ross J, Darke S, Williamson A, Havard A. The impact of treatment on 3 years' outcome for heroin dependence: findings from the Australian Treatment Outcome Study (ATOS). Addiction. 2008;103(1):80\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRawson RA, Marinelli-Casey P, Anglin MD, Dickow A, Frazier Y, Gallagher C, et al. A multi‐site comparison of psychosocial approaches for the treatment of methamphetamine dependence. Addiction. 2004;99(6):708\u0026ndash;17.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKing J, Dow J, Stevenson B. Measuring outcomes for TC clients: higher ground drug rehabilitation trust. Therapeutic Communities: Int J Ther Communities. 2016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilkins C, Prasad J, Wong K, Rychert M. Recent trends in illegal drug use in New Zealand, 2006\u0026ndash;2014: Findings from the 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 illicit drug monitoring system (IDMS). Social and Health Outcomes Research and Evaluation, College of Health, Massey University; 2015.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGossop M, Darke S, Griffiths P, Hando J, Powis B, Hall W, et al. The Severity of Dependence Scale (SDS): psychometric properties of the SDS in English and Australian samples of heroin, cocaine and amphetamine users. Addiction. 1995;90(5):607\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSheehan DV, Lecrubier Y, Sheehan KH, Amorim P, Janavs J, Weiller E et al. The Mini-International Neuropsychiatric Interview (MINI): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry. 1998.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcLellan A, Cacciola J, Zanis D. The addiction severity index-lite. Center for the Studies on Addiction, University of Pennsylvania/Philadelphia VA Medical Center; 1997.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalji A, Romano I, Levitt E, Sousa S, Rush B, MacKillop J, et al. Psychometric evaluation of the treatment entry questionnaire to assess extrinsic motivation for inpatient addiction treatment. Drug Alcohol Depend. 2022;2:100014.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUstun B, Adler LA, Rudin C, Faraone SV, Spencer TJ, Berglund P, et al. The World Health Organization adult attention-deficit/hyperactivity disorder self-report screening scale for DSM-5. JAMA Psychiatry. 2017;74(5):520\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDarke S, Hall W, Wodaki A, Heather N, Ward J. Development and validation of a multidimensional instrument for assessing outcome of treatment among opiate users: the Opiate Treatment Index. Br J Addict. 1992;87(5):733\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJablensky A, McGrath J, Herrman H, Castle D, Gureje O, Evans M, et al. Psychotic disorders in urban areas: an overview of the Study on Low Prevalence Disorders. Aust NZ J Psychiatry. 2000;34(2):221\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLukoff D, Nuechterlein K, Ventura J. Manual for the expanded brief psychiatric rating scale. Schizophr Bull. 1986;12:594\u0026ndash;602.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKessler RC, Barker PR, Colpe LJ, Epstein JF, Gfroerer JC, Hiripi E, et al. Screening for serious mental illness in the general population. Arch Gen Psychiatry. 2003;60(2):184\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTopp L, Mattick RP. Choosing a cut-off on the Severity of Dependence Scale (SDS) for amphetamine users. Addiction. 1997;92(7):839\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSobell L, Sobell M, Buchan G, Cleland P, Fedoroff I, Leo G et al. Timeline followback method (drugs, cigarettes, and marijuana). In 30th Annual Meeting of the Association for Advancement of Behavior Therapy1996 Nov 21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDolan P. Modeling valuations for EuroQol health states. Medical care. 1997:1095\u0026thinsp;\u0026ndash;\u0026thinsp;108.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMclachlan A. Whāngaihia te hua o oranga ki ō tatou whānau whānui: Ko te tikanga o te whakamahinga o Hua Oranga. Wellington: Te Rau Ora; 2022.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJoe GW, Simpson DD, Broome KMJD. Retention and patient engagement models for different treatment modalities in DATOS. Drug Alcohol Depend. 1999;57(2):113\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAustin PC, Stuart EA. Moving towards best practice when using inverse probability of treatment weighting (IPTW) using the propensity score to estimate causal treatment effects in observational studies. Stat Med. 2015;34(28):3661\u0026ndash;79.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBerk RA. An introduction to sample selection bias in sociological data. Am Sociol Rev. 1983:386\u0026ndash;98.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCiketic S, Hayatbakhsh R, McKetin R, Doran CM, Najman JM. Cost-effectiveness of counselling as a treatment option for methamphetamine dependence. J Subst Use. 2015;20(4):239\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHusereau D, Drummond M, Petrou S, Carswell C, Moher D, Greenberg D, et al. Consolidated health economic evaluation reporting standards (CHEERS) statement. Cost Eff Resource Allocation. 2013;11(1):6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eManca A, Hawkins N, Sculpher MJ. Estimating mean QALYs in trial-based cost‐effectiveness analysis: the importance of controlling for baseline utility. Health Econ. 2005;14(5):487\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTuthill EL, Maltby AE, DiClemente K, Pellowski JA. Longitudinal qualitative methods in health behavior and nursing research: assumptions, design, analysis and lessons learned. Int J Qual Methods. 2020;19:1609406920965799.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalman L, Brunton L, Molassiotis A. Developing longitudinal qualitative designs: lessons learned and recommendations for health services research. BMC Med Res Methodol. 2013;13(1):14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAudulv \u0026Aring;, Hall EO, Kneck \u0026Aring;, Westergren T, Fegran L, Pedersen MK, et al. Qualitative longitudinal research in health research: a method study. BMC Med Res Methodol. 2022;22(1):255.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNeale J. Iterative categorization (IC): a systematic technique for analysing qualitative data. Addiction. 2016;111(6):1096\u0026ndash;106.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVon Elm E, Altman DG, Egger M, Pocock SJ, G\u0026oslash;tzsche PC, Vandenbroucke JP. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet. 2007;370(9596):1453\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eInternational Committee of Medical Journal Editors. Defining the Role of Authors and Contributors: International Committee of Medical Journal Editors; [cited 2025 12/03/2025]. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html\u003c/span\u003e\u003cspan address=\"https://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Methamphetamine Use Disorder, Treatment, Longitudinal, Cohort, Longitudinal Qualitative, Māori","lastPublishedDoi":"10.21203/rs.3.rs-6256539/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6256539/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Methamphetamine is the second most used illicit drug in Aotearoa New Zealand, after cannabis. Regular and heavy users of methamphetamine are likely to develop methamphetamine use disorder (MUD), and significant health and psychiatric harm. Effective treatments for MUD are limited, and relapses are common. Tū Whakaruruhau is a programme of research that aims to understand what treatment approaches are effective in managing MUD and related physical and psychological harms, in New Zealand.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: Tū Whakaruruhau comprises two studies. The first study is a 24-month longitudinal cohort study that will follow people receiving treatment and those not in treatment for MUD (outpatient counselling, residential treatment, and detoxification) in the Auckland, Northland, and Waikato regions of New Zealand. Data collection will occur on entry to treatment (baseline), then 3-, 12-, and 24-months later. The primary outcome is self-reported methamphetamine use (days used in the past month) at 12-months. Secondary outcomes include psychiatric comorbidity, polydrug use, change in diagnosis of MUD, criminal involvement, healthcare utilisation, and expectations and experiences of treatment. Three hundred and twenty participants (50% indigenous Māori, 240 in the Treatment Group, 80 in the Non treatment Group) will be sought for 90% power on the primary outcome. The second study is a longitudinal qualitative study involving interviews at baseline, 6-, and 12-months with 30 participants (50% Māori) from the Treatment Group, to explore their expectations of treatment and lived experiences of treatment for MUD over time.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiscussion: \u003c/strong\u003eThis programme of work will provide the first evidence of treatment outcomes for MUD and the relative effectiveness of the current approaches to treating MUD, in the New Zealand context. It will provide information on what factors predict better and more equitable health outcomes. The incorporation of qualitative interviews will ensure that the participants’ treatment experiences are captured. This will inform perspectives about what treatment approaches work, and do not work, so that the most appropriate interventions are made available to support consumer needs. Findings will be incorporated into relevant reviews, informing practice and policy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAustralian and New Zealand Clinical Trial Registry: ACTRN12623000438651p. Registered 1\u003csup\u003est\u003c/sup\u003e May 2023.\u003c/p\u003e","manuscriptTitle":"Tū Whakaruruhau: The evaluation of treatment outcomes for methamphetamine dependence in Aotearoa New Zealand – study protocol for a prospective longitudinal cohort study and longitudinal qualitative study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-03-20 10:01:52","doi":"10.21203/rs.3.rs-6256539/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d386b6be-b26e-4357-8476-60dc5badac03","owner":[],"postedDate":"March 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-03-21T06:23:50+00:00","versionOfRecord":[],"versionCreatedAt":"2025-03-20 10:01:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6256539","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6256539","identity":"rs-6256539","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}