Delivery Models of Diabetic Retinopathy Services in Low and Middle-income Countries: A scoping review protocol

Delivery Models of Diabetic Retinopathy Services in Low and Middle-income Countries: A scoping review protocol | 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 Research Article Delivery Models of Diabetic Retinopathy Services in Low and Middle-income Countries: A scoping review protocol Shaffi Yusuf Mdala, Petros Kayange, Thokozani Zungu, Alexander Heatley, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5886984/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Background Diabetic retinopathy(DR) is among the leading causes of blindness worldwide, including in low- and middle-income countries (LMICs) where the majority of people living with diabetes (PLWD) reside. The World Health Organisation (WHO) endorses DR screening along with timely treatment of those identified with treatable disease as a cost-effective intervention for the prevention of blindness from DR. Although this has been demonstrated to be successful in some high income countries, the service delivery models may not be practical for LMICs due to limited access to screening and treatment services. This scoping review aims to identify, map, and assess the available evidence on DR service delivery models for LMICs. Methods We will search MEDLINE, Embase, Global Health and CENTRAL on the Cochrane Library along with grey literature, to identify relevant publications in all languages reporting on DR service delivery models in LMICs. We will include studies of all designs and technical reports published since the year 2000, where the publication describes the set-up for DR service delivery in terms of one or more of the following aspects of delivery; screening, diagnosis, treatment, follow-up, referral to specialist ophthalmic care and linkage with general diabetes care. We will map current practices and identify gaps in the literature by analysing the included studies. Two reviewers will screen search results independently and data extraction will also be carried out by two reviewers and any discrepancies will be resolved through discussion or arbitration with a third reviewer. The results of the search and the study inclusion process will be presented using the PRISMA-ScR flow diagram and a narrative synthesis will be used to report the results. Discussion This scoping review will provide an overview of DR service delivery models in LMICs, synthesising findings from different countries. The review will offer insights into the components of the DR service delivery models and the extent of the evidence on the effectiveness of the models. The results will be of interest to policymakers planning on optimising DR services or conducting research aimed at reducing the burden of DR in LMICs. Scoping review registration OSF: https://doi.org/10.17605/OSF.IO/E4YX5 Diabetic retinopathy (DR) Service delivery models Low- and middle-income countries (LMICs) Screening Treatment Cost effectiveness Figures Figure 1 BACKGROUND Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM) and is the leading cause of preventable blindness in working age adults in many countries[ 1 ]. The International Diabetes Federation (IDF) estimates that there are 537 million adults (10.5%) living with DM globally and this number is expected to rise to 783 million by 2045 [ 2 ]. For sub-Saharan Africa alone, the total number of people living with diabetes (PLWD) is predicted to increase from 24 to 55 million by 2045, representing the highest percentage increase (129%) of all IDF regions [ 2 ]. With the rapid increase in the global burden of DM, the global prevalence of DR will also rise, especially in low- and middle-income countries (LMICs) where more than 80% of PLWD reside [ 2 ]. While the crude prevalence of the four leading causes of blindness has decreased over the past three decades, DR-related blindness has increased by 68%, mainly in LMICs [ 3 , 4 ]. In Africa, it is estimated that 35% of PLWD have DR, and close to 18.4% have sight-threatening DR (STDR) that requires treatment to avoid vision loss [ 5 ]. Vision loss due to DR is prevented through regular retinal screening aimed at timely identification of DR, followed by referral and treatment [ 6 ]. For high-income countries (HICs), the World Health Organisation (WHO) endorses systematic DR screening for all people with DM and laser photocoagulation treatment for those with DR as a cost-effective intervention in the management of DM [ 7 , 8 ]. Systematic DR screening is organised at a population level and includes a well-described screening pathway that is governed by protocols and guidelines and supported by an information system that can monitor performance [ 9 ]. It also incorporates quality standards based on evidence that service providers follow and the screening test is offered to an identified cohort of PLWD at an agreed interval based on a register that enables call and recall of patients [ 9 ]. Systematic DR screening coupled with treatment is cost-effective in terms of sight years preserved compared with no screening or opportunistic screening [ 10 , 11 ]. The cost-effectiveness of population-based DR screening also varies depending on the screening interval used and risk stratification of the population screened [ 12 , 13 ]. The diabetic eye screening programme in England is an example of a programme that has been able to reduce the burden of blindness from DR. The programme was launched in 2003 and it targets all PLWD from the age of 12 years and above [ 14 ]. It reached national coverage in 2008 and has maintained annual uptake levels of more than 80% [ 15 , 16 ]. As a quality assurance measure, the non-ophthalmologist graders in the programme participate in continuous professional development courses and undertake monthly tests to ensure that they maintain a high level of diagnostic accuracy [ 14 ]. Currently, DR is no longer the leading cause of blindness among working-age adults in England and this is attributed to the impact of the national diabetic eye screening programme [ 14 , 17 ]. While some HICs have successfully implemented national-level systematic DR screening programs, such models are often difficult to replicate in LMICs. This is due to shortage of skilled eye health workers, inadequate or non-existent referral systems and a shortage of diagnostic and treatment infrastructure [ 18 ]. In addition, eye health services in LMICs are usually clustered in cities and not available to hard-to-reach rural populations who may sometimes comprise the majority of the population especially in low income countries (LICs) [ 19 ]. Consequently, many LMICs have struggled to develop DR programmes as highlighted in one scoping review where no LIC had a policy to guide implementation of a diabetic eye screening programme [ 20 ]. With the predicted global epidemic of DM which will disproportionally affect LMICs, many eye care programmes in LMICs have started to establish DR programmes by mainly adapting current HIC practices to their local contexts[ 21 ]. However, there is still limited knowledge about the models for delivering DR services in LMICs. To address this gap, there is thus an urgent need to identify current service delivery models and assess the available evidence for those models in LMICs. This scoping review will map the existing DR service delivery models used in LMICs by identifying their key components and their reported effectiveness. A scoping review approach has been chosen because this methodology enables mapping of the extent, range and the nature of literature on broad or evolving topics and identification of gaps in the literature[ 22 ]. We will synthesize the literature that describes the processes of care for PLWD who are at risk for or have developed DR. We will describe how these services are organized, delivered, and accessed by patients in LMICs. The findings will be reported considering the setup for screening, diagnosis, treatment, follow-up, referral to specialist ophthalmic care and linkage with general DM care. METHODS Protocol design This protocol follows a methodological framework for scoping reviews that was developed by Arksey and O’Malley and further refined by Levac et al [ 22 – 25 ] and it includes six iterative steps: (i) identifying the research question; (ii) identifying the relevant studies; (iii) selecting studies to be included; (iv) charting the data; (v) collating, summarizing, and reporting the results and (vi) consulting stakeholders to identify gaps not explored in the literature. The sixth step is optional and will not be a part of this protocol. We developed this protocol with guidance from the Joanna Briggs Institute (JBI) methodology for scoping reviews [ 26 , 27 ] and it is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews (PRISMA-ScR) [ 28 ] (Additional file 1). This protocol has been prospectively registered on Open Science Framework (OSF) (Additional file 2) and any future amendments to the protocol will be documented on the OSF site ( https://doi.org/10.17605/OSF.IO/E4YX5 ) Step 1: Identifying the Scoping Review Question The primary research question for this scoping review is: What delivery models for DR services are used in low- and middle-income countries (LMICs)? The secondary research question is as follows: What is the nature and extent of the evidence as to the effectiveness of the current models of delivering DR services in LMICs? We define a DR service delivery model as the organisation of structures and processes that are used in a health system to offer DR screening and management services. While effectiveness will be defined as the outcome of a DR service delivery model in terms of cost effectiveness and impact on the incidence of blindness due to DR. Being an iterative process, it is possible that additional research questions may be generated, informed by emerging themes from the body of the literature identified during the scoping review. To address the two research questions, we have adapted a conceptual framework developed by Donabedian in 1966, originally proposed to assess the quality of a healthcare system [ 29 , 30 ]. Our framework utilizes Donabedian’s three components to measure quality of care - structure, process, and outcome – and maps the DR care continuum to these components. For DR, structure refers to the characteristics of the setting in which the service is provided e.g. the health system level and the resources available such as personnel offering the screening or treatment services and the equipment used. Process refers to the methods and interactions by which DR care is provided such as usage of screening or treatment protocols and linkage between the DR services and DM services. It also describes whether the screening approach used is systematic or opportunistic, where DR screening is offered and performed when patients with DM present to a health facility to access general DM services or other care without any scheduled appointment for DR-specific care. Outcomes are the effects of a service on the health status of a population[ 29 ]. In the context of DR service delivery, this refers to the health gains realised from DR screening and treatment such as the incidence of blindness due to DR. It also includes any measure of cost-effectiveness of the DR intervention utilised e.g. years of sight saved, health-related quality of life, Fig. 1 . Step 2: Identifying relevant studies Eligibility Criteria This scoping review will consider both experimental and quasi-experimental study designs including randomized controlled trials, non-randomized controlled trials, before and after studies and interrupted time-series studies. We will also include analytical observational studies such as prospective and retrospective cohort studies, case-control studies and analytical cross-sectional studies as well as descriptive observational study designs. This will include case studies, case series, individual case reports and descriptive cross-sectional studies. In addition, we will include qualitative studies, policy documents and technical or evaluation reports authored in LMICs. The review will include publications regarding people of any age living with any type of DM who are eligible for an intervention meant to screen and/or treat DR. We will consider all relevant publications written in all languages and pertaining to a LMIC setting as classified by the World Bank [ 30 ]. For studies, we will only include publications of primary studies and this will include MSc or PhD theses and we will also search the references of relevant systematic or literature reviews on the topic. Searches will be restricted to publications from the year 2000 to date, reflecting a period that has witnessed significant growth in DR technologies and services [ 30 , 31 ]. We will exclude studies that focus on discussing technical aspects of diagnostic tools or treatments (such as diagnostic accuracy or treatment efficacy studies) without describing the health system context. We will also exclude studies conducted in high income countries, editorials and conference abstracts. The search strategy for the scoping review will be based on the PCC framework (population, concept, and context) [ 27 ] as described in Table 1 . Table 1 Eligibility criteria Inclusion criteria Exclusion criteria Population People with a diagnosis of DM (Type 1, Type 2 or gestational DM) of any age or gender who require DR screening and/or treatment Other populations not fitting the inclusion criteria Concept DR care, defined as any intervention aimed at screening, diagnosing and/or treating DR • Studies focusing on technical aspects of diagnostic tools or treatments that do not describe the health system context. Context Low- and middle-income countries Other countries not fitting the inclusion criteria Evidence Sources • Peer-reviewed publications of primary research and MSc or PhD theses • Technical or evaluation reports • Abstract reported in the English language • Published since the year 2000 • Commentaries, opinion pieces, letters, editorials, trial registrations, abstracts, book chapters, protocols • Conference proceedings • Articles with no full text • Systematic or literature reviews Study design Interventional, observational and qualitative study designs Information Sources The research team, in consultation with the Information Specialist (IG) undertook an initial search of MEDLINE (Ovid) to identify articles on the topic. The text words contained in the titles and abstracts of relevant articles, and the index terms used to describe the articles were used to develop a full search strategy for Embase (Ovid), Global Health (Ovid), and CENTRAL on the Cochrane Library (Additional file 3). These databases have been selected due to their broad subject coverage including clinical care, public health, health policy development and health services research. To capture a comprehensive range of data on service delivery model, we will also identify grey literature by directly contacting key stakeholders via email and giving them four weeks to respond. The list of relevant stakeholders will be compiled using publicly available information and networks within the ophthalmology and global eye health communities. This will include Ministries of Health, national Ophthalmological Societies, and non-governmental organizations (NGOs) known to support DR and eye health services in all LMICs according to classification by the World Bank [ 30 ]. We will specifically request technical reports, publications, program evaluations, or any other relevant documents that report the DR service delivery models that are implemented in the countries. One follow-up email will be sent after four weeks to non-responding stakeholders to maximize data acquisition. All retrieved documents will be included in the review if they meet the pre-defined inclusion criteria. Search strategy An experienced information specialist (IG) developed a comprehensive search strategy in consultation with the study team that employs keywords, medical subject headings (MeSH) or subject headings search terms that relate to DR, LMICs, and healthcare delivery models. The search strategy, including all identified keywords and index terms, was adapted for each included database. Search strategies for all databases are presented in Additional file 3. We will also use a snowballing approach to screen reference lists of all included sources of evidence to identify additional studies Step 3: Study selection The search results will be collated and imported into Covidence systematic review software, Veritas Health Innovation, Melbourne, Australia [ 32 ] and duplicates will be removed. To ensure reliability between reviewers, a training exercise will be conducted before the screening process. Following a pilot test, two reviewers (SM, TZ, AH and CB working in pairs) will independently review each title and abstract using the software to identify publications that are potentially relevant. We will calculate interrater agreement using Cohen’s Kappa statistic (Κ) and a K value of ≥ 0.8 will be considered as a high level of agreement. If a low level of agreement is observed, the training will be repeated or the inclusion criteria will be clarified. Full-text articles will be retrieved and reviewed in detail against the inclusion criteria by two reviewers (SM, TZ, AH and CB working in pairs). Full text publications that do not meet the inclusion criteria will be excluded and listed in the appendix of the scoping review along with the reasons for exclusion. Any disagreements that arise between the reviewers at each stage of the selection process will be resolved through discussion, or with an additional reviewer. The results of the search and the study inclusion process will be reported using the PRISMA-ScR flow diagram [ 28 ] Step 4: Charting the data Data will be extracted from the included publications by two independent reviewers using Covidence software [ 32 ]. The data extraction template will be piloted independently by two investigators on 5 to 10 publications of different designs. If poor inter-rater reliability (K < 0.8) is noted between the investigators during the piloting stage, the investigators will be retrained on the data extraction criteria. Any discrepancies will be discussed and if consensus is not reached, a third reviewer will arbitrate and the data extraction form will be updated accordingly. Any modifications to the data extraction form will be detailed in the report The extracted data will include specific details about the publications included, the participants and the structure, processes and outcomes of the DR services in each study context, Table 2 . Table 2 Data items to be extracted Data categories Data Publication characteristics Title, year of study/publication, country of study/publication, funding source Methods Study design or type of publication Population characteristics Sample size, age, gender Structure • Organisation of screening o Setting for DR screening (rural/urban) o Health system level where DR screening services are offered (community/outreach/mobile clinic, primary, secondary or tertiary,) o Screening personnel (trained eye health workers or task-shifting/task-sharing cadres) o Equipment used: direct ophthalmoscope, slit lamp/indirect fundoscopy, static fundus camera, portable fundus camera o Supporting staff for call-and-recall or follow-up • Organisation of treatment o Setting for DR treatment (rural/urban) o Health system level where DR treatment services are offered (primary, secondary, tertiary) o Treatment providers (ophthalmologists, allied eye health workers, task-shifting/task-sharing cadres) o Laser machine availability Process • Screening procedure o Screening approach (systematic/opportunistic) o Screening frequency (annual/biannual) o Grading procedure (Artificial intelligence, Telemedicine or point of care grading by health worker) o Diagnostic test accuracy of screening (sensitivity, specificity, positive predictive value or negative predictive value) o Screening Coverage: The percentage of eligible PLWD who underwent DR screening within a specified time frame o Screening Uptake: The percentage of PLWD who were offered DR screening and underwent screening within a specified time frame o Positivity rate: Proportion of screened patients diagnosed with any level of DR o Most prevalent stage of DR at first diagnosis (and percentage) • Treatment procedures o Referral uptake/treatment attendance rate: The percentage of patients with referable DR who presented for treatment following screening and referral o Usage of treatment guidelines or protocols o Treatment options (anti-VEGF, laser, steroids, vitrectomy) • Linkage mechanisms o Call-and-recall/ follow-up system used o Linkage of screening with specialist ophthalmic care (integrated or vertical) o Linkage of screening with DM care (Integrated or vertical) • Barriers/enablers to the delivery of DR screening/treatment services • Barriers/enablers to accessing DR screening/treatment services Outcomes • Incidence of blindness from DR or of STDR • Any measure of cost-effectiveness of DR screening and/or treatment e.g. years of sight saved, health-related quality of life Step 5: Collating, summarizing, and reporting the results The results will be summarised using tables and a narrative synthesis approach and the findings will be presented in line with the PRISMA-ScR guidelines. Studies will be mapped according to attributes such as geographical location, service delivery processes, available evidence and study design. This will enable us to identify gaps in the literature and highlight where data is lacking or inconsistent across different regions and aspects of DR service delivery. Themes and sub-themes relevant to the research questions will be developed around DR screening and DR treatment with descriptions of the structure of the DR services, the processes of delivering care and the outcomes reported from the DR programmes in various LMICs. DISCUSSION To the best of our knowledge, this is the first review to identify the scope of evidence and gaps in the literature on delivery models for DR services in LMICs. This scoping review will provide a comprehensive overview of the key components that constitute DR services in LMICs by mapping the extent of the literature on the different DR screening and treatment approaches. In addition, we will identify the reported patient outcomes and effectiveness of the different components of the DR service delivery models identified. One limitation of our study is that there may be delivery models for DR services that are used in LMICs but are not reported in the scope of literature that will be included in this review. However, by synthesizing evidence identified from diverse LMIC contexts, the study will inform policymakers and healthcare providers on potential applicable approaches to optimizing DR service delivery in resource-constrained settings. The review will also highlight gaps in the literature, guiding future research and initiatives aimed at integrating DR services into health systems to mitigate the growing burden of DR in LMICs. Abbreviations DM Diabetes mellitus DR Diabetic retinopathy HIC High-income country LMIC Low- and middle-income country OSF Open Science Framework PLWD People living with diabetes PRISMA-ScR Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review WHO World Health Organisation Declarations Ethics approval and consent to participate Not applicable Consent for publication Not applicable Availability of data and materials Not applicable—no data sets currently available. Competing interests None declared Funding This research was funded by the National Institute of Health and Care Research (NIHR), as part of a Global Health project in which CB is the principal investigator ( NIHR158474). MB is supported by the Wellcome Trust (207472/Z/17/Z) Authors' contributions CB conceptualised the scoping review. SM drafted and revised the protocol with suggestions from PK, TZ, AH, IG, JE, APM, MB and CB, who all reviewed the protocol and provided feedback on the draft. IG constructed the search. All authors read and approved the final manuscript. Acknowledgements Not applicable Authors' information International Centre for Eye Health, Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom. Shaffi Mdala, Iris Gordon, Jennifer Evans, Ana Patricia Marques, Matthew Burton & Covadonga Bascaran Ophthalmology Unit, Department of Surgery, Kamuzu University of Health Sciences, Blantyre, Malawi. Shaffi Mdala, Petros Kayange & Thokozani Zungu University College London, Faculty of Medical Sciences, London, United Kingdom Alexander Heatley Corresponding author Correspondence to Shaffi Mdala Supplementary information Additional file 1. Reporting standards – PRISMA ScR Checklist. Additional file 2. 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Mdala","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0002-3581-523X","institution":"London School of Hygiene \u0026 Tropical Medicine Faculty of Infectious and Tropical Diseases","correspondingAuthor":true,"prefix":"","firstName":"Shaffi","middleName":"Yusuf","lastName":"Mdala","suffix":""},{"id":476262933,"identity":"21916cf0-31ee-4706-8532-853bf342a1a9","order_by":1,"name":"Petros Kayange","email":"","orcid":"","institution":"Kamuzu University of Health Sciences: University of Malawi College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Petros","middleName":"","lastName":"Kayange","suffix":""},{"id":476262934,"identity":"2e5f240d-7078-4033-8a1e-7c7a52a16d55","order_by":2,"name":"Thokozani Zungu","email":"","orcid":"","institution":"Kamuzu University of Health Sciences: University of Malawi College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Thokozani","middleName":"","lastName":"Zungu","suffix":""},{"id":476262935,"identity":"eaa6b429-a803-4e87-ba7b-4a7a03b3d508","order_by":3,"name":"Alexander Heatley","email":"","orcid":"","institution":"UCL Faculty of Medical Sciences: University College London Faculty of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Alexander","middleName":"","lastName":"Heatley","suffix":""},{"id":476262936,"identity":"7049d2f6-28d7-4083-84af-a90d8120d05b","order_by":4,"name":"Iris Gordon","email":"","orcid":"","institution":"London School of Hygiene \u0026 Tropical Medicine Faculty of Infectious and Tropical Diseases","correspondingAuthor":false,"prefix":"","firstName":"Iris","middleName":"","lastName":"Gordon","suffix":""},{"id":476262937,"identity":"61650f27-c280-4176-b8af-c3fb81def53b","order_by":5,"name":"Jennifer R Evans","email":"","orcid":"","institution":"London School of Hygiene \u0026 Tropical Medicine Faculty of Infectious and Tropical Diseases","correspondingAuthor":false,"prefix":"","firstName":"Jennifer","middleName":"R","lastName":"Evans","suffix":""},{"id":476262938,"identity":"efeba2d2-6e25-4f66-acec-181bc23c48a0","order_by":6,"name":"Ana Patricia Marques","email":"","orcid":"","institution":"London School of Hygiene \u0026 Tropical Medicine Faculty of Infectious and Tropical Diseases","correspondingAuthor":false,"prefix":"","firstName":"Ana","middleName":"Patricia","lastName":"Marques","suffix":""},{"id":476262939,"identity":"e36bef43-7cb7-4b04-b7b3-cfb11dee3801","order_by":7,"name":"Matthew J Burton","email":"","orcid":"","institution":"London School of Hygiene \u0026 Tropical Medicine Faculty of Infectious and Tropical Diseases","correspondingAuthor":false,"prefix":"","firstName":"Matthew","middleName":"J","lastName":"Burton","suffix":""},{"id":476262940,"identity":"cc196751-da58-4593-8ae7-c42eafdd021e","order_by":8,"name":"Covadonga Bascaran","email":"","orcid":"","institution":"London School of Hygiene \u0026 Tropical Medicine Faculty of Infectious and Tropical Diseases","correspondingAuthor":false,"prefix":"","firstName":"Covadonga","middleName":"","lastName":"Bascaran","suffix":""}],"badges":[],"createdAt":"2025-01-23 09:35:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5886984/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5886984/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":85795914,"identity":"fb33fd37-21da-48ea-a06d-113ced5d7d58","added_by":"auto","created_at":"2025-07-01 19:37:51","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":99843,"visible":true,"origin":"","legend":"\u003cp\u003eConceptual Framework for DR Service Delivery Models\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5886984/v1/8f0e0449cff98a1c759d15d4.jpg"},{"id":85796661,"identity":"e984146e-7aff-4387-a461-6f24fec30c0b","added_by":"auto","created_at":"2025-07-01 19:53:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":929887,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5886984/v1/faab989d-44aa-475e-b1af-f70e11c4e286.pdf"},{"id":85795913,"identity":"3d9bf6f6-e675-4523-9075-7461bcac8b5b","added_by":"auto","created_at":"2025-07-01 19:37:51","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":50531,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile1PRISMAScRChecklist.docx","url":"https://assets-eu.researchsquare.com/files/rs-5886984/v1/25a030f9e7d5e811317e6af6.docx"},{"id":85795356,"identity":"4e9d5b88-0d9a-46a9-b936-8b4d0b43f87c","added_by":"auto","created_at":"2025-07-01 19:21:51","extension":"docx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":54920,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile3Searchstrategy.docx","url":"https://assets-eu.researchsquare.com/files/rs-5886984/v1/6f161b9989159f164f21cb21.docx"}],"financialInterests":"","formattedTitle":"Delivery Models of Diabetic Retinopathy Services in Low and Middle-income Countries: A scoping review protocol","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eDiabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM) and is the leading cause of preventable blindness in working age adults in many countries[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The International Diabetes Federation (IDF) estimates that there are 537\u0026nbsp;million adults (10.5%) living with DM globally and this number is expected to rise to 783\u0026nbsp;million by 2045 [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. For sub-Saharan Africa alone, the total number of people living with diabetes (PLWD) is predicted to increase from 24 to 55\u0026nbsp;million by 2045, representing the highest percentage increase (129%) of all IDF regions [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWith the rapid increase in the global burden of DM, the global prevalence of DR will also rise, especially in low- and middle-income countries (LMICs) where more than 80% of PLWD reside [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. While the crude prevalence of the four leading causes of blindness has decreased over the past three decades, DR-related blindness has increased by 68%, mainly in LMICs [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. In Africa, it is estimated that 35% of PLWD have DR, and close to 18.4% have sight-threatening DR (STDR) that requires treatment to avoid vision loss [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eVision loss due to DR is prevented through regular retinal screening aimed at timely identification of DR, followed by referral and treatment [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. For high-income countries (HICs), the World Health Organisation (WHO) endorses systematic DR screening for all people with DM and laser photocoagulation treatment for those with DR as a cost-effective intervention in the management of DM [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Systematic DR screening is organised at a population level and includes a well-described screening pathway that is governed by protocols and guidelines and supported by an information system that can monitor performance [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. It also incorporates quality standards based on evidence that service providers follow and the screening test is offered to an identified cohort of PLWD at an agreed interval based on a register that enables call and recall of patients [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSystematic DR screening coupled with treatment is cost-effective in terms of sight years preserved compared with no screening or opportunistic screening [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The cost-effectiveness of population-based DR screening also varies depending on the screening interval used and risk stratification of the population screened [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe diabetic eye screening programme in England is an example of a programme that has been able to reduce the burden of blindness from DR. The programme was launched in 2003 and it targets all PLWD from the age of 12 years and above [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. It reached national coverage in 2008 and has maintained annual uptake levels of more than 80% [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. As a quality assurance measure, the non-ophthalmologist graders in the programme participate in continuous professional development courses and undertake monthly tests to ensure that they maintain a high level of diagnostic accuracy [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Currently, DR is no longer the leading cause of blindness among working-age adults in England and this is attributed to the impact of the national diabetic eye screening programme [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhile some HICs have successfully implemented national-level systematic DR screening programs, such models are often difficult to replicate in LMICs. This is due to shortage of skilled eye health workers, inadequate or non-existent referral systems and a shortage of diagnostic and treatment infrastructure [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In addition, eye health services in LMICs are usually clustered in cities and not available to hard-to-reach rural populations who may sometimes comprise the majority of the population especially in low income countries (LICs) [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Consequently, many LMICs have struggled to develop DR programmes as highlighted in one scoping review where no LIC had a policy to guide implementation of a diabetic eye screening programme [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWith the predicted global epidemic of DM which will disproportionally affect LMICs, many eye care programmes in LMICs have started to establish DR programmes by mainly adapting current HIC practices to their local contexts[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. However, there is still limited knowledge about the models for delivering DR services in LMICs. To address this gap, there is thus an urgent need to identify current service delivery models and assess the available evidence for those models in LMICs.\u003c/p\u003e \u003cp\u003eThis scoping review will map the existing DR service delivery models used in LMICs by identifying their key components and their reported effectiveness. A scoping review approach has been chosen because this methodology enables mapping of the extent, range and the nature of literature on broad or evolving topics and identification of gaps in the literature[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. We will synthesize the literature that describes the processes of care for PLWD who are at risk for or have developed DR. We will describe how these services are organized, delivered, and accessed by patients in LMICs. The findings will be reported considering the setup for screening, diagnosis, treatment, follow-up, referral to specialist ophthalmic care and linkage with general DM care.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eProtocol design\u003c/h2\u003e \u003cp\u003eThis protocol follows a methodological framework for scoping reviews that was developed by Arksey and O\u0026rsquo;Malley and further refined by Levac et al [\u003cspan additionalcitationids=\"CR23 CR24\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] and it includes six iterative steps: (i) identifying the research question; (ii) identifying the relevant studies; (iii) selecting studies to be included; (iv) charting the data; (v) collating, summarizing, and reporting the results and (vi) consulting stakeholders to identify gaps not explored in the literature. The sixth step is optional and will not be a part of this protocol.\u003c/p\u003e \u003cp\u003eWe developed this protocol with guidance from the Joanna Briggs Institute (JBI) methodology for scoping reviews [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] and it is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews (PRISMA-ScR) [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] (Additional file 1). This protocol has been prospectively registered on Open Science Framework (OSF) (Additional file 2) and any future amendments to the protocol will be documented on the OSF site (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.17605/OSF.IO/E4YX5\u003c/span\u003e\u003cspan address=\"10.17605/OSF.IO/E4YX5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eStep 1: Identifying the Scoping Review Question\u003c/h3\u003e\n\u003cp\u003eThe primary research question for this scoping review is: What delivery models for DR services are used in low- and middle-income countries (LMICs)? The secondary research question is as follows: What is the nature and extent of the evidence as to the effectiveness of the current models of delivering DR services in LMICs?\u003c/p\u003e \u003cp\u003eWe define a DR service delivery model as the organisation of structures and processes that are used in a health system to offer DR screening and management services. While effectiveness will be defined as the outcome of a DR service delivery model in terms of cost effectiveness and impact on the incidence of blindness due to DR. Being an iterative process, it is possible that additional research questions may be generated, informed by emerging themes from the body of the literature identified during the scoping review.\u003c/p\u003e \u003cp\u003eTo address the two research questions, we have adapted a conceptual framework developed by Donabedian in 1966, originally proposed to assess the quality of a healthcare system [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Our framework utilizes Donabedian\u0026rsquo;s three components to measure quality of care - structure, process, and outcome \u0026ndash; and maps the DR care continuum to these components.\u003c/p\u003e \u003cp\u003eFor DR, structure refers to the characteristics of the setting in which the service is provided e.g. the health system level and the resources available such as personnel offering the screening or treatment services and the equipment used. Process refers to the methods and interactions by which DR care is provided such as usage of screening or treatment protocols and linkage between the DR services and DM services. It also describes whether the screening approach used is systematic or opportunistic, where DR screening is offered and performed when patients with DM present to a health facility to access general DM services or other care without any scheduled appointment for DR-specific care. Outcomes are the effects of a service on the health status of a population[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. In the context of DR service delivery, this refers to the health gains realised from DR screening and treatment such as the incidence of blindness due to DR. It also includes any measure of cost-effectiveness of the DR intervention utilised e.g. years of sight saved, health-related quality of life, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eStep 2: Identifying relevant studies\u003c/h3\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eEligibility Criteria\u003c/h2\u003e \u003cp\u003eThis scoping review will consider both experimental and quasi-experimental study designs including randomized controlled trials, non-randomized controlled trials, before and after studies and interrupted time-series studies. We will also include analytical observational studies such as prospective and retrospective cohort studies, case-control studies and analytical cross-sectional studies as well as descriptive observational study designs. This will include case studies, case series, individual case reports and descriptive cross-sectional studies. In addition, we will include qualitative studies, policy documents and technical or evaluation reports authored in LMICs.\u003c/p\u003e \u003cp\u003eThe review will include publications regarding people of any age living with any type of DM who are eligible for an intervention meant to screen and/or treat DR. We will consider all relevant publications written in all languages and pertaining to a LMIC setting as classified by the World Bank [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. For studies, we will only include publications of primary studies and this will include MSc or PhD theses and we will also search the references of relevant systematic or literature reviews on the topic. Searches will be restricted to publications from the year 2000 to date, reflecting a period that has witnessed significant growth in DR technologies and services [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWe will exclude studies that focus on discussing technical aspects of diagnostic tools or treatments (such as diagnostic accuracy or treatment efficacy studies) without describing the health system context. We will also exclude studies conducted in high income countries, editorials and conference abstracts. The search strategy for the scoping review will be based on the PCC framework (population, concept, and context) [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] as described in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEligibility criteria\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInclusion criteria\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eExclusion criteria\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePopulation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePeople with a diagnosis of DM (Type 1, Type 2 or gestational DM) of any age or gender who require DR screening and/or treatment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOther populations not fitting the inclusion criteria\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eConcept\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDR care, defined as any intervention aimed at screening, diagnosing and/or treating DR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026bull; Studies focusing on technical aspects of diagnostic tools or treatments that do not describe the health system context.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eContext\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLow- and middle-income countries\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOther countries not fitting the inclusion criteria\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEvidence Sources\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Peer-reviewed publications of primary research and MSc or PhD theses\u003c/p\u003e \u003cp\u003e\u0026bull; Technical or evaluation reports\u003c/p\u003e \u003cp\u003e\u0026bull; Abstract reported in the English language\u003c/p\u003e \u003cp\u003e\u0026bull; Published since the year 2000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026bull; Commentaries, opinion pieces, letters, editorials, trial registrations, abstracts, book chapters, protocols\u003c/p\u003e \u003cp\u003e\u0026bull; Conference proceedings\u003c/p\u003e \u003cp\u003e\u0026bull; Articles with no full text\u003c/p\u003e \u003cp\u003e\u0026bull; Systematic or literature reviews\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStudy design\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInterventional, observational and qualitative study designs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eInformation Sources\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe research team, in consultation with the Information Specialist (IG) undertook an initial search of MEDLINE (Ovid) to identify articles on the topic. The text words contained in the titles and abstracts of relevant articles, and the index terms used to describe the articles were used to develop a full search strategy for Embase (Ovid), Global Health (Ovid), and CENTRAL on the Cochrane Library (Additional file 3). These databases have been selected due to their broad subject coverage including clinical care, public health, health policy development and health services research.\u003c/p\u003e \u003cp\u003eTo capture a comprehensive range of data on service delivery model, we will also identify grey literature by directly contacting key stakeholders via email and giving them four weeks to respond. The list of relevant stakeholders will be compiled using publicly available information and networks within the ophthalmology and global eye health communities. This will include Ministries of Health, national Ophthalmological Societies, and non-governmental organizations (NGOs) known to support DR and eye health services in all LMICs according to classification by the World Bank [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. We will specifically request technical reports, publications, program evaluations, or any other relevant documents that report the DR service delivery models that are implemented in the countries. One follow-up email will be sent after four weeks to non-responding stakeholders to maximize data acquisition. All retrieved documents will be included in the review if they meet the pre-defined inclusion criteria.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSearch strategy\u003c/h3\u003e\n\u003cp\u003eAn experienced information specialist (IG) developed a comprehensive search strategy in consultation with the study team that employs keywords, medical subject headings (MeSH) or subject headings search terms that relate to DR, LMICs, and healthcare delivery models. The search strategy, including all identified keywords and index terms, was adapted for each included database. Search strategies for all databases are presented in Additional file 3. We will also use a snowballing approach to screen reference lists of all included sources of evidence to identify additional studies\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStep 3: Study selection\u003c/h2\u003e \u003cp\u003eThe search results will be collated and imported into Covidence systematic review software, Veritas Health Innovation, Melbourne, Australia [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] and duplicates will be removed. To ensure reliability between reviewers, a training exercise will be conducted before the screening process. Following a pilot test, two reviewers (SM, TZ, AH and CB working in pairs) will independently review each title and abstract using the software to identify publications that are potentially relevant. We will calculate interrater agreement using Cohen\u0026rsquo;s Kappa statistic (Κ) and a K value of \u0026ge;\u0026thinsp;0.8 will be considered as a high level of agreement. If a low level of agreement is observed, the training will be repeated or the inclusion criteria will be clarified.\u003c/p\u003e \u003cp\u003eFull-text articles will be retrieved and reviewed in detail against the inclusion criteria by two reviewers (SM, TZ, AH and CB working in pairs). Full text publications that do not meet the inclusion criteria will be excluded and listed in the appendix of the scoping review along with the reasons for exclusion. Any disagreements that arise between the reviewers at each stage of the selection process will be resolved through discussion, or with an additional reviewer. The results of the search and the study inclusion process will be reported using the PRISMA-ScR flow diagram [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eStep 4: Charting the data\u003c/h3\u003e\n\u003cp\u003eData will be extracted from the included publications by two independent reviewers using Covidence software [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. The data extraction template will be piloted independently by two investigators on 5 to 10 publications of different designs. If poor inter-rater reliability (K\u0026thinsp;\u0026lt;\u0026thinsp;0.8) is noted between the investigators during the piloting stage, the investigators will be retrained on the data extraction criteria. Any discrepancies will be discussed and if consensus is not reached, a third reviewer will arbitrate and the data extraction form will be updated accordingly. Any modifications to the data extraction form will be detailed in the report\u003c/p\u003e \u003cp\u003eThe extracted data will include specific details about the publications included, the participants and the structure, processes and outcomes of the DR services in each study context, Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eData items to be extracted\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eData categories\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eData\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePublication characteristics\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTitle, year of study/publication, country of study/publication, funding source\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMethods\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eStudy design or type of publication\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePopulation characteristics\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSample size, age, gender\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eStructure\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Organisation of screening\u003c/p\u003e \u003cp\u003eo Setting for DR screening (rural/urban)\u003c/p\u003e \u003cp\u003eo Health system level where DR screening services are offered (community/outreach/mobile clinic, primary, secondary or tertiary,)\u003c/p\u003e \u003cp\u003eo Screening personnel (trained eye health workers or task-shifting/task-sharing cadres)\u003c/p\u003e \u003cp\u003eo Equipment used: direct ophthalmoscope, slit lamp/indirect fundoscopy, static fundus camera, portable fundus camera\u003c/p\u003e \u003cp\u003eo Supporting staff for call-and-recall or follow-up\u003c/p\u003e \u003cp\u003e\u0026bull; Organisation of treatment\u003c/p\u003e \u003cp\u003eo Setting for DR treatment (rural/urban)\u003c/p\u003e \u003cp\u003eo Health system level where DR treatment services are offered (primary, secondary, tertiary)\u003c/p\u003e \u003cp\u003eo Treatment providers (ophthalmologists, allied eye health workers, task-shifting/task-sharing cadres)\u003c/p\u003e \u003cp\u003eo Laser machine availability\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eProcess\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Screening procedure\u003c/p\u003e \u003cp\u003eo Screening approach (systematic/opportunistic)\u003c/p\u003e \u003cp\u003eo Screening frequency (annual/biannual)\u003c/p\u003e \u003cp\u003eo Grading procedure (Artificial intelligence, Telemedicine or point of care grading by health worker)\u003c/p\u003e \u003cp\u003eo Diagnostic test accuracy of screening (sensitivity, specificity, positive predictive value or negative predictive value)\u003c/p\u003e \u003cp\u003eo Screening Coverage: The percentage of eligible PLWD who underwent DR screening within a specified time frame\u003c/p\u003e \u003cp\u003eo Screening Uptake: The percentage of PLWD who were offered DR screening and underwent screening within a specified time frame\u003c/p\u003e \u003cp\u003eo Positivity rate: Proportion of screened patients diagnosed with any level of DR\u003c/p\u003e \u003cp\u003eo Most prevalent stage of DR at first diagnosis (and percentage)\u003c/p\u003e \u003cp\u003e\u0026bull; Treatment procedures\u003c/p\u003e \u003cp\u003eo Referral uptake/treatment attendance rate: The percentage of patients with referable DR who presented for treatment following screening and referral\u003c/p\u003e \u003cp\u003eo Usage of treatment guidelines or protocols\u003c/p\u003e \u003cp\u003eo Treatment options (anti-VEGF, laser, steroids, vitrectomy)\u003c/p\u003e \u003cp\u003e\u0026bull; Linkage mechanisms\u003c/p\u003e \u003cp\u003eo Call-and-recall/ follow-up system used\u003c/p\u003e \u003cp\u003eo Linkage of screening with specialist ophthalmic care (integrated or vertical)\u003c/p\u003e \u003cp\u003eo Linkage of screening with DM care (Integrated or vertical)\u003c/p\u003e \u003cp\u003e\u0026bull; Barriers/enablers to the delivery of DR screening/treatment services\u003c/p\u003e \u003cp\u003e\u0026bull; Barriers/enablers to accessing DR screening/treatment services\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOutcomes\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Incidence of blindness from DR or of STDR\u003c/p\u003e \u003cp\u003e\u0026bull; Any measure of cost-effectiveness of DR screening and/or treatment e.g. years of sight saved, health-related quality of life\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eStep 5: Collating, summarizing, and reporting the results\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe results will be summarised using tables and a narrative synthesis approach and the findings will be presented in line with the PRISMA-ScR guidelines. Studies will be mapped according to attributes such as geographical location, service delivery processes, available evidence and study design. This will enable us to identify gaps in the literature and highlight where data is lacking or inconsistent across different regions and aspects of DR service delivery. Themes and sub-themes relevant to the research questions will be developed around DR screening and DR treatment with descriptions of the structure of the DR services, the processes of delivering care and the outcomes reported from the DR programmes in various LMICs.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eTo the best of our knowledge, this is the first review to identify the scope of evidence and gaps in the literature on delivery models for DR services in LMICs. This scoping review will provide a comprehensive overview of the key components that constitute DR services in LMICs by mapping the extent of the literature on the different DR screening and treatment approaches. In addition, we will identify the reported patient outcomes and effectiveness of the different components of the DR service delivery models identified.\u003c/p\u003e \u003cp\u003eOne limitation of our study is that there may be delivery models for DR services that are used in LMICs but are not reported in the scope of literature that will be included in this review. However, by synthesizing evidence identified from diverse LMIC contexts, the study will inform policymakers and healthcare providers on potential applicable approaches to optimizing DR service delivery in resource-constrained settings. The review will also highlight gaps in the literature, guiding future research and initiatives aimed at integrating DR services into health systems to mitigate the growing burden of DR in LMICs.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDiabetes mellitus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDiabetic retinopathy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHIC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHigh-income country\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLMIC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLow- and middle-income country\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOSF\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOpen Science Framework\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePLWD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePeople living with diabetes\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePRISMA-ScR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePreferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWHO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eWorld Health Organisation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u0026mdash;no data sets currently available.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone declared\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was funded by the National Institute of Health and Care Research (NIHR), as part of a Global Health project in which CB is the principal investigator ( NIHR158474). MB is supported by the Wellcome Trust (207472/Z/17/Z)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCB conceptualised the scoping review. SM drafted and revised the protocol with suggestions from PK, TZ, AH, IG, JE, APM, MB and CB, who all reviewed the protocol and provided feedback on the draft. IG constructed the search. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInternational Centre for Eye Health, Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom. \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eShaffi Mdala, Iris Gordon, Jennifer Evans, Ana Patricia Marques, Matthew Burton \u0026amp; Covadonga Bascaran\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOphthalmology Unit, Department of Surgery, Kamuzu University of Health Sciences, Blantyre, Malawi.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eShaffi Mdala, Petros Kayange \u0026amp; Thokozani Zungu\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUniversity College London, Faculty of Medical Sciences, London, United Kingdom\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAlexander Heatley\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorresponding author\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence to \u003cstrong\u003eShaffi Mdala\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eSupplementary information\u003c/p\u003e\n\u003cp\u003eAdditional file 1. Reporting standards \u0026ndash; PRISMA ScR Checklist.\u003c/p\u003e\n\u003cp\u003eAdditional file 2. Registration on OSF: https://doi.org/10.17605/OSF.IO/E4YX5\u003c/p\u003e\n\u003cp\u003eAdditional file 3. Search strategy\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCheung N, Mitchell P, Wong TY. Diabetic retinopathy. Lancet [Internet]. 2010 Jul 10 [cited 2024 Oct 19];376(9735):124\u0026ndash;36. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.thelancet.com/article/S0140673609621243/fulltext\u003c/span\u003e\u003cspan address=\"http://www.thelancet.com/article/S0140673609621243/fulltext\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIDF Diabetes Atlas. 10th edition [Internet]. 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Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://datahelpdesk.worldbank.org/knowledgebase/articles/906519-world-bank-country-and-lending-groups\u003c/span\u003e\u003cspan address=\"https://datahelpdesk.worldbank.org/knowledgebase/articles/906519-world-bank-country-and-lending-groups\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSabanayagam C, Banu R, Chee ML, Lee R, Wang YX, Tan G et al. Incidence and progression of diabetic retinopathy: a systematic review. Lancet Diabetes Endocrinol [Internet]. 2019 Feb 1 [cited 2024 Oct 17];7(2):140\u0026ndash;9. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.thelancet.com/article/S2213858718301281/fulltext\u003c/span\u003e\u003cspan address=\"http://www.thelancet.com/article/S2213858718301281/fulltext\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVeritas Health Innovation. Covidence systematic review software [Internet]. Melbourne; Available from: www.covidence.org.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"systematic-reviews","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sysr","sideBox":"Learn more about [Systematic Reviews](http://systematicreviewsjournal.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/sysr/default.aspx","title":"Systematic Reviews","twitterHandle":"@MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Diabetic retinopathy (DR), Service delivery models, Low- and middle-income countries (LMICs), Screening, Treatment, Cost effectiveness","lastPublishedDoi":"10.21203/rs.3.rs-5886984/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5886984/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eDiabetic retinopathy(DR) is among the leading causes of blindness worldwide, including in low- and middle-income countries (LMICs) where the majority of people living with diabetes (PLWD) reside. The World Health Organisation (WHO) endorses DR screening along with timely treatment of those identified with treatable disease as a cost-effective intervention for the prevention of blindness from DR. Although this has been demonstrated to be successful in some high income countries, the service delivery models may not be practical for LMICs due to limited access to screening and treatment services. This scoping review aims to identify, map, and assess the available evidence on DR service delivery models for LMICs.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe will search MEDLINE, Embase, Global Health and CENTRAL on the Cochrane Library along with grey literature, to identify relevant publications in all languages reporting on DR service delivery models in LMICs. We will include studies of all designs and technical reports published since the year 2000, where the publication describes the set-up for DR service delivery in terms of one or more of the following aspects of delivery; screening, diagnosis, treatment, follow-up, referral to specialist ophthalmic care and linkage with general diabetes care. We will map current practices and identify gaps in the literature by analysing the included studies. Two reviewers will screen search results independently and data extraction will also be carried out by two reviewers and any discrepancies will be resolved through discussion or arbitration with a third reviewer. The results of the search and the study inclusion process will be presented using the PRISMA-ScR flow diagram and a narrative synthesis will be used to report the results.\u003c/p\u003e\u003ch2\u003eDiscussion\u003c/h2\u003e \u003cp\u003eThis scoping review will provide an overview of DR service delivery models in LMICs, synthesising findings from different countries. The review will offer insights into the components of the DR service delivery models and the extent of the evidence on the effectiveness of the models. The results will be of interest to policymakers planning on optimising DR services or conducting research aimed at reducing the burden of DR in LMICs.\u003c/p\u003e\u003ch2\u003eScoping review registration\u003c/h2\u003e \u003cp\u003eOSF: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.17605/OSF.IO/E4YX5\u003c/span\u003e\u003cspan address=\"10.17605/OSF.IO/E4YX5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e","manuscriptTitle":"Delivery Models of Diabetic Retinopathy Services in Low and Middle-income Countries: A scoping review protocol","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-01 19:21:46","doi":"10.21203/rs.3.rs-5886984/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-06-30T11:42:18+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-25T10:57:26+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-03-14T16:06:57+00:00","index":"","fulltext":""},{"type":"submitted","content":"Systematic Reviews","date":"2025-01-23T04:33:41+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"systematic-reviews","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sysr","sideBox":"Learn more about [Systematic Reviews](http://systematicreviewsjournal.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/sysr/default.aspx","title":"Systematic Reviews","twitterHandle":"@MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"15e703c7-0149-4349-9497-118b6f20f7ef","owner":[],"postedDate":"July 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-07-01T19:21:46+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-01 19:21:46","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5886984","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5886984","identity":"rs-5886984","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}