The prevalence of foot pain and association with baseline characteristics in people participating in education and supervised exercise for knee or hip osteoarthritis: a cross-sectional study of 26,003 participants from the GLA:D® registry

The prevalence of foot pain and association with baseline characteristics in people participating in education and supervised exercise for knee or hip osteoarthritis: a cross-sectional study of 26,003 participants from the GLA:D® registry | 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 The prevalence of foot pain and association with baseline characteristics in people participating in education and supervised exercise for knee or hip osteoarthritis: a cross-sectional study of 26,003 participants from the GLA:D® registry Lucy S Gates, Lindsey Cherry, Dorte T Grønne, Ewa M Roos, Soren T Skou This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3099487/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 Nov, 2023 Read the published version in Journal of Foot and Ankle Research → Version 1 posted 7 You are reading this latest preprint version Abstract Background Osteoarthritis (OA) affecting the knee or hip is highly prevalent in the general population and has associated high disease burden. Early identification of modifiable risk factors that prevent, limit, or resolve disease symptoms is critical. Foot pain may represent a potentially modifiable factor however little is known about the prevalence of foot pain in people with knee or hip OA nor whether foot pain is associated with clinical characteristics. The main aim of this study was therefore to determine the prevalence of foot pain in people with knee or hip OA attending an education and supervised exercise-based intervention in Denmark (GLA:D ® ) and determine if baseline demographic or clinical characteristics are associated with foot pain. Methods Analysis was conducted on baseline data of 26,003 people with symptomatic knee or hip OA completing a body mannequin as part of the Good Life with osteoArthritis in Denmark (GLA:D ® ) primary care programme. Odds Ratios (OR) and 95% confidence intervals (CI) were calculated to estimate the strength of association between baseline clinical characteristics (including pain severity in worst knee/hip joint, number of painful knee/hip joints, pain medication use and physical activity level) and the presence of baseline foot pain. Results Twelve percent of participants (n = 3,049) reported foot pain. In those people with index knee OA (n = 19,391), knee pain severity (OR 1.01 CI 1.00, 1.01), number of painful knee/hip joints (OR 1.67 CI 1.58, 1.79), and use of pain medication (OR 1.23 CI 1.12, 1.36) were statistically associated with foot pain. Excluding use of pain medication, similar associations were seen in those with index hip OA. Conclusion Twelve percent of people with knee or hip OA participating in GLA:D ® had foot pain. Those with worse knee/hip pain, and greater number of painful joints were more likely to report foot pain. This study is the first to demonstrate a significant relationship between clinical characteristics and foot pain in people with knee or hip OA participating in education and supervised exercise. Future investigation should consider the role that foot pain may play on knee and hip related outcomes following therapeutic intervention. osteoarthritis knee hip foot pain cross-sectional Figures Figure 1 Figure 2 Background and rationale Osteoarthritis (OA) is the most prevalent chronic joint disease with hip and knee OA causing the greatest burden to the population in terms of pain, stiffness and disability ( 1 ). Due to a lack of effective disease modifying treatments for OA, attention has also turned to identifying modifiable risk factors to help alleviate the disease burden ( 2 , 3 ). Understanding the role that clinical characteristics play in knee and hip OA is therefore important and may contribute new insight into the design, conduct or content of interventions to reduce disease burden. Foot pain is highly prevalent in the general population, with estimates ranging from 13–36% ( 4 ) and is notably higher in people with radiographic knee OA with estimates of around 25% ( 5 ). Furthermore, the presence of foot/ankle pain in people with symptomatic radiographic knee OA has previously been shown to be associated with increased risk of worsening knee pain over time ( 6 ). However, little is known about the epidemiology of foot pain in people with symptomatic knee or hip OA, or the potential strength of association between clinical characteristics of this group and foot pain. Thus, the overall aim of this study was to estimate the prevalence of foot pain in people with knee or hip OA and to determine if baseline clinical characteristics were associated with foot pain. Methods Design, aim and context Secondary data analysis was conducted on cross-sectional baseline data of individuals enrolled on Good Life with osteoArthritis in Denmark (GLA:D ® ). GLA:D ® was initiated in 2013 with the overarching aim of implementing clinical guidelines for the treatment of knee and hip OA in clinical practice to facilitate high quality care of people with OA in the Danish population. GLA:D ® consists of three mandatory elements: a 2-day course for physiotherapists; 8 weeks of patient education and supervised neuromuscular exercise therapy for people with knee or hip OA symptoms delivered by a certified physiotherapist in clinical practice; and data entry into the national GLA:D ® registry, with data from baseline, three and 12 month follow-up (7). Data are objectively measured, therapist-reported and patient-reported (7). This study, reported according to the STROBE guidelines for reporting cross-sectional studies (8), utilized baseline data to estimate the prevalence of foot pain in people with knee or hip OA participating in GLA:D ® and to determine if baseline clinical characteristics were associated with foot pain. Ethical approval and consent According to the ethics committee of the North Denmark Region, ethical approval of GLA:D ® was not needed. However, ethics approval for secondary analysis was received from University of Southampton Ethics and Research Online (ethics no: 56534). GLA:D ® was approved by the Danish Data Protection Agency (SDU; 10.084). According to the Danish Data Protection Act patient consent for secondary analysis was not required as personal data was processed exclusively for research and statistical purposes. Participants and sampling All participants in the GLA:D ® registry have knee and/or hip joint symptoms or functional limitations associated with knee and/or hip OA that have resulted in contact with the health care system. For the current study we included individuals enrolled in GLA:D ® between 1st of July 2014 and 8th of April 2018 and who had completed a baseline pain body mannequin. Patients enrolled in GLA:D ® after this date were not included as pain mannequin data were not collected due to a database error (9 th of April 2018 - 3 rd of November 2020). Self-reported, objective clinical, & derived outcome measures All independent variables were selected based on prior research (9,10) or clinical reasoning. Where it was believed other variables may introduce a confounding effect based upon clinical reasoning these were also included where available. The presence of foot pain was derived from positive indication on a 56-site body diagram (4 sites based on plantar or superior aspect of left or right feet; figure 1) indicating where the participant had experienced pain during the last 24 hours. The prevalence of foot pain was calculated as a percentage of those with i) pain in either foot, ii) pain in both feet, or iii) pain in neither foot. Index knee and hip pain were derived from specific questions based on the most affected joint (hip or knee) and side (left or right). The prevalence of knee and hip symptoms was based on a positive indication of knee or hip joint being affected and the distribution of knee and hip symptoms based on side affected. The number of painful knee/hip joints were calculated based on a count of 1-4. Pain intensity in the worst knee/hip joint during the past month was captured (VAS 0-100) and use of pain medication in the past three months for knee or hip pain recorded (Yes/No). Current physical activity level was measured using the University of California Los Angeles (UCLA) activity score (11), which assessed activity levels in the past 4 weeks, providing a range of levels from one (wholly inactive) to ten (very high activity). Activity levels were dichotomized as low to moderate activity (UCLA score 1–6) and high activity (UCLA score 7–10)(12). The presence of depression was derived from the self-reported question “Do you have a depression?” (Yes/No). Sex was derived directly from the Civil Registration number (CPR) which identifies every citizen in Denmark and age derived from a combination of the Civil Registration number (containing date of birth) and date of initiating the intervention. Body Mass Index (BMI, kg/m2) was calculated from height and weight assessment completed during baseline clinical visit. Statistical analysis Complete case analysis was used due to the low number of missing observations (0.49%) within the main exposure variable (most affected knee/hip joint). Participants who had both outcome and exposure data available and were not missing observations from any potential confounders (age and sex) were included in the analyses. Comparisons were made between those with and without missing data for key variables. Descriptive data for demographic characteristics and baseline foot, knee, and hip pain were calculated using means and standard deviations or frequencies. Univariable and Multivariable logistic regression analysis was undertaken to calculate the strength of association between baseline clinical characteristics (including pain severity in worst knee/hip joint, number of painful knee/hip joints, pain medication use, and physical activity level) and the outcome of foot pain, in those selected for hip or knee OA. Analysis was stratified by those with index knee problems and index hip problems. Directed acyclic graphs (DAG) were used as a visual representation of associations between variables (figure 2). Multicollinearity was assessed by tolerance and variance inflation factor (VIF). All analyses were carried out in Stata 15.1 (StataCorp, College Station, TX, USA). Results Of 26,003 individuals included in this study, 74.6% (n=19,391) were enrolled with the knee as their most affected joint and 25.4% (n=6,612) with hip as the most affected joint. Of 26,003 included patients (mean age 64.83 ± 9.69 years, mean BMI 28.32 ± 5.26), 72.2% (n= 18,784) were registered as female, 4.4% (n=1,137) reported having depression, 63.0% (n=16,370) used pain medication, 64.3% (n=16,706) had a low to moderate ULCA score. Those patients missing data were older (mean difference of 2.5 years) and had lower knee pain intensity scores (mean difference in scores of -5.25). There was a higher percentage of females with missing data (1.2%) than males (0.9%) (see Appendix 1 for missing data table). **Table 1** Irrespective of the index joint, 83.6% (n=21,738) participants reported either left or right knee affected and 38.5% (n=10,017) reported either left or right hip affected. The prevalence of foot pain in those with knee or hip OA was 11.7% (n=3,049). Specifically, 12.4% (n=2,396) of those whose most affected joint was the knee and 9.9% (n=653) of those whose most affected joint was the hip, reported foot pain (see table 1 for distribution of foot, knee, and hip pain). Of those with left knee symptoms (n=15,328), 11.0% also had left foot pain and 11.5% with right knee symptoms (n=15,535) also had right foot pain, irrespective of index joint. Likewise, in those with left hip symptoms (n= 5,825) 10.7% (n= 624) also had left foot pain, and of those with right hip symptoms (n=6,386), 11.2% (n= 712) also had right foot pain. Adjusted regression analysis showed that the number of painful knee/hip joints and knee/hip pain severity in the worst knee/hip joint, were significantly associated with foot pain in those with knee and hip OA, whilst taking pain medication showed association with foot pain in those with index knee OA only (table 2). Physical activity was negatively associated with foot pain; however, this relationship was attenuated within fully adjusted analysis. **Table 2** Discussion The overall prevalence of foot pain in people with symptoms of knee or hip OA attending the GLA:D® programme was 12%, this differed slightly according to whether the index joint was knee (12%) or hip (10%). The number of other painful knee/hip joints and pain severity in worst knee/hip joint, were associated with foot pain for those with knee or hip OA. Use of pain medication was associated with foot pain in those with index knee OA only. No associations were seen for physical activity level and foot pain in either those with index knee or hip pain. The prevalence of foot pain was slightly lower than previously reported general population prevalence estimates of 13–36% ( 4 ). It is possible that the use of a full body pain mannequin to estimate specific joint pain may underestimate multi-site pain prevalence. Also the definition of foot pain in GLA:D® was based on pain during the last 24h, which does not reflect fluctuations in foot pain over a longer period of time, nor does it consider symptoms such as aching or stiffness unlike other cohort studies ( 4 ). Paterson et al ( 5 ) previously reported a notably higher prevalence of foot pain (25%) than identified in this work, in their cohort analysis of people with symptomatic radiographic knee OA, defined by frequent knee symptoms (including pain, aching, or stiffness in and around the knee on most days of the month for at least 1 month in the past year) and radiographic evidence of knee OA (Kellgren/Lawrence grade ≥ 2). The difference could be accounted for by variance in sampling strategy between studies; people were enrolled onto the GLA:D® programme based upon having self-reported knee/hip joint problems that resulted in contact with the Danish healthcare system, where they were assessed by the treating therapist to have symptomatic OA ( 7 ), and thus may represent a wider spectrum of disease, including those with potentially earlier pathogenesis and minimal radiographically observable change. This is the first study to determine a prevalence estimate of foot pain in those with symptomatic hip OA and as such similar comparisons cannot yet be drawn. It is unclear from cross-sectional observation alone whether foot pain precedes, coincides with, or follows the presence of symptomatic knee or hip OA. Clinically, such information could provide useful steer for future treatment targets and as such future longitudinal studies are recommended. This study has however highlighted that whilst the direction of this relationship is unclear, the odds of having foot pain is significantly increased with knee or hip pain severity and the presence of pain in more than one hip or knee joint. This highlights the importance of including foot pain measures within the clinical assessment of knee and hip symptoms, particularly in those with a diagnosis of OA. Given that it is known that people with pre-operative foot pain are more likely to have poorer clinically important outcomes following knee arthroplasty ( 13 ), the potential for foot pain to negatively impact concurrent knee and hip symptoms and vice versa should therefore be considered. Participants of the GLA:D® programme with knee or hip OA symptoms and foot pain were more likely to experience worse pain intensity and pain in more sites. Furthermore, those with symptomatic knee OA and foot pain were also more likely to be using analgesic medicine. The findings reported here are consistent with similar prior observations, where worsening knee pain was associated with foot symptoms over four years in those with symptomatic radiographic knee OA ( 6 ). It is noteworthy that factors such as worsening pain have also been associated with poorer outcome or disease progression in previous studies of knee and hip OA interventions ( 14 , 15 ). Arguably, based on our findings, future consideration should also be given to the effect that foot health/pain could have upon the likely success of various treatments for knee or hip OA, including exercise and surgical intervention. Future epidemiological studies could seek to build upon the data presented here to explore the wider impact of foot pain upon people living with symptomatic knee or hip OA. We may then consider the need to optimize foot health as a potentially modifiable treatment target for wider determinants of lower limb health or health-related outcomes. Some of the limitations of this study have already been described. In addition, there is a potential lack of generalisability as the current study only includes those who sought education and exercise for their knee/hip OA pain, also other factors that were not accounted for may have contributed to the associations found. We do not know the reasons for foot pain, nor the longevity of its presence, and this type of information would be useful within a future longitudinal study to better understand the relationship between foot, knee, and hip symptoms. Conclusion Twelve percent of people with knee or hip OA participating in patient education and exercise reported having foot pain, to which a range of clinical knee and hip characteristics were associated. Foot pain may therefore be an important factor to consider in the assessment of knee and hip OA. Future longitudinal epidemiological research is required to explore the natural history of foot pain in people with OA, and the potential for foot pain to be a modifiable therapeutic target to reduce disease/ symptom progression or increase treatment success. Declarations Ethics approval and consent to participate According to the ethics committee of the North Denmark Region, ethical approval of GLA:D ® was not needed. However, ethics approval for secondary analysis was received from University of Southampton Ethics and Research Online (ethics no: 56534). GLA:D ® was approved by the Danish Data Protection Agency (SDU; 10.084). According to the Danish Data Protection Act patient consent for secondary analysis and reporting was not required as personal data was processed exclusively for research and statistical purposes. Consent for publication According to the Danish Data Protection Act patient consent for secondary analysis and reporting was not required as personal data was processed exclusively for research and statistical purposes. No personal identifiable data is included within this publication. Availability of data and materials The data that support the findings of this study are available from Søren T. Skou [email protected] or Ewa M. Roos [email protected] but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of Søren T. Skou [email protected] or Ewa M. Roos [email protected] on behalf of the GLA:D® programme team. Competing interests EMR is on the Editorial Board of Osteoarthritis and Cartilage, the developer of the Knee injury and Osteoarthritis Outcome Score (KOOS) and several other patient-reported outcome measures and co-founder of GLA:D®, a not-for profit initiative hosted at University of Southern Denmark aimed at implementing clinical guidelines for osteoarthritis in clinical practice. EMR has received personal fees from TrustMed-Ed and Learn Physio outside the submitted work. STS is associate editor of the Journal of Orthopaedic and Sports Physical Therapy, has received personal fees from Munksgaard, TrustMe-Ed, and Nestlé Health Science, outside the submitted work, and is co-founder of GLA:D®. The other authors declare that they have no competing interests. Funding No direct funding was obtained to undertake this research. The initiation of GLA:D® was partly funded by the Danish Physiotherapy Association’s fund for research, education and practice development; the Danish Rheumatism Association; and the Physiotherapy Practice Foundation. STS is currently funded by a program grant from Region Zealand (Exercise First) and two grants from the European Union’s Horizon 2020 research and innovation program, one from the European Research Council (MOBILIZE, grant agreement No 801790) and the other under grant agreement No 945377 (ESCAPE). These institutions had no role in the study. Authors contributions STS, EMR, DTG contributed to the registration and conduct of the original source data. DTG contributed to the data cleaning and retrieval for this study. All authors contributed to the design, analysis, and reporting of this research. All authors read and approved the final manuscript. Acknowledgements The authors wish to acknowledge the participants of the GLA:D ® study for their time and contribution to data collection and the staff and volunteers involved in the delivery and running of the GLA:D ® programme. For the purpose of open access, the author has applied a Creative Commons attribution license (CC BY) to any Author Accepted Manuscript version arising from this submission. References Litwic A, Edwards MH, Dennison EM, Cooper C. Epidemiology and burden of osteoarthritis. British Medical Bulletin. 2013;105(1):185-99. Grässel S, Muschter D. Recent advances in the treatment of osteoarthritis. F1000Res. 2020;9:F1000 Faculty Rev-325. Georgiev T, Angelov AK. Modifiable risk factors in knee osteoarthritis: treatment implications. Rheumatology International. 2019;39(7):1145-57. Gates LS, Arden NK, Hannan MT, Roddy E, Gill TK, Hill CL, et al. Prevalence of Foot Pain Across an International Consortium of Population-Based Cohorts. Arthritis Care Res (Hoboken). 2019;71(5):661-70. Paterson KL, Hinman RS, Hunter DJ, Wrigley TV, Bennell KL. Impact of concurrent foot pain on health and functional status in people with knee osteoarthritis: data from the osteoarthritis initiative. Arthritis care & research. 2015;67(7):989-95. Paterson KL, Kasza J, Hunter DJ, Hinman RS, Menz HB, Peat G, et al. Longitudinal association between foot and ankle symptoms and worsening of symptomatic radiographic knee osteoarthritis: data from the osteoarthritis initiative. Osteoarthritis Cartilage. 2017;25(9):1407-13. Skou ST, Roos EM. Good Life with osteoArthritis in Denmark (GLA:D™): evidence-based education and supervised neuromuscular exercise delivered by certified physiotherapists nationwide. BMC Musculoskeletal Disorders. 2017;18(1):72. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP; STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)statement: guidelines for reporting observational studies. J Clin Epidemiol. 2008 Apr;61(4):344-9. PMID: 18313558 Hill CL, Gill TK, Menz HB, Taylor AW. Prevalence and correlates of foot pain in a population-based study: the North West Adelaide health study. Journal of foot and ankle research. 2008;1(1):2. Awale A, Dufour AB, Katz P, Menz HB, Hannan MT. Link Between Foot Pain Severity and Prevalence of Depressive Symptoms. Arthritis care & research. 2016;68(6):871-6. Zahiri CA, Schmalzried TP, Szuszczewicz ES, Amstutz HC. Assessing activity in joint replacement patients. The Journal of arthroplasty. 1998;13(8):890-5. Lübbeke A, Zimmermann-Sloutskis D, Stern R, Roussos C, Bonvin A, Perneger T, et al. Physical Activity Before and After Primary Total Hip Arthroplasty: A Registry-Based Study. Arthritis Care & Research. 2014;66(2):277-84. Gates LS, Bowen CJ, Sanchez-Santos MT, Delmestri A, Arden NK. Do foot & ankle assessments assist the explanation of 1 year knee arthroplasty outcomes? Osteoarthritis and Cartilage. 2017;25(6):892-8. Birch S, Stilling M, Mechlenburg I, Hansen TB. The association between pain catastrophizing, physical function and pain in a cohort of patients undergoing knee arthroplasty. BMC Musculoskeletal Disorders. 2019;20(1):421. Judge A, Arden NK, Cooper C, Kassim Javaid M, Carr AJ, Field RE, et al. Predictors of outcomes of total knee replacement surgery. Rheumatology. 2012;51(10):1804-13. Tables Table 1. Presence and distribution of foot, knee, and hip pain, stratified by index joint Index knee Pain (n=19,391) Index hip pain (n=6,612) Foot pain presence, n (%) Yes 2,396 (12.4) 653 (9.9) Foot pain distribution Left * 1,947 (10.0) 524 (7.9) *not exclusive to one side Right * 1,986 (10.2) 523 (7.9) Left (unilateral) 410 (2.1) 130 (2.0) Right (unilateral) 449 (2.3) 129 (2.0) Bilateral 1537 (7.9) 394 (6.0) Either foot 2,396 (12.4) 653 (9.9) Most affected joint side, n (%) Right 10,104 (52.1) 3,581 (54.2) Knee/Hip pain severity, mean (SD), VAS 48.12 (22.1) 48.10 (21.5) Knee pain distribution, n (%) Left 5,140 (26.5) 1,063 (16.1) Right 5,457 (28.1) 953 (14.4) Bilateral 8,794 (45.35) 331 (5.01) No Knee pain NA 4,265 (64.50) Hip pain distribution, n (%) Left 1,373 (7.08) 2,258 (34.15) Right 1,521 (7.84) 2,671 (40.40) Bilateral 511 (2.64) 1,683 (25.45) No Hip pain 15,986 (82.44) NA Number of knee/hip joints affected, n (%) One 8,080 (41.67) 2,922 (44.19) Two 10,284 (53.03) 3,188 (48.22) Three 655 (3.38) 333 (5.04) Four 372 (1.92) 169 (2.56) Table 2. Associations between foot pain and baseline characteristics based in adjusted multivariable models Index knee (n= 19,391) Index hip (n=6,612) Univariable Multivariable Univariable Multivariable OR 95% CI OR 95% CI OR 95% CI OR 95% CI Number of painful knee/hip joints 1.76 1.65, 1.87 1.68 1.58, 1.79 1.72 1.55, 1.91 1.62 1.48, 1.83 Knee/hip pain severity in worst knee/hip joint 1.01 1.01, 1.01 1.01 1.00, 1.01 1.01 1.01, 1.02 1.01 1.01, 1.01 Use of pain medication for knee/hip 1.48 1.35, 1.62 1.23 1.12, 1.36 1.31 1.09, 1.56 1.07 0.89, 1.29 Physical activity level 0.94 0.92, 0.96 1.00 0.97, 1.02 0.94 0.90, 0.98 1.00 0.95, 1.05 Supplementary Files Appendix.docx Cite Share Download PDF Status: Published Journal Publication published 23 Nov, 2023 Read the published version in Journal of Foot and Ankle Research → Version 1 posted Reviewers agreed at journal 09 Jul, 2023 Reviewers invited by journal 09 Jul, 2023 Reviewer # 1 agreed at journal 08 Jul, 2023 Editor assigned by journal 05 Jul, 2023 Submission checks completed at journal 04 Jul, 2023 Editor invited by journal 04 Jul, 2023 First submitted to journal 25 Jun, 2023 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. 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09:04:34","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3099487/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3099487/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13047-023-00673-5","type":"published","date":"2023-11-23T15:00:49+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":39980290,"identity":"043e127b-bebc-49a8-b50d-3573dd5ef8b3","added_by":"auto","created_at":"2023-07-13 14:10:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":358867,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cu\u003e56-site body diagram.\u003c/u\u003e The presence of foot pain was derived from positive indication on a 56-site body diagram (4 sites based on plantar or superior aspect of left or right feet).\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-3099487/v1/346a413b71d763515a6c40d8.png"},{"id":39980291,"identity":"a9fbcd6a-94fc-49f0-b6c9-15118bbbf30c","added_by":"auto","created_at":"2023-07-13 14:10:45","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":220697,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cu\u003eVariable inter-relational Directed Acyclic Graph (DAG)\u003c/u\u003e.\u003c/p\u003e\n\u003cp\u003eThe DAG provides visual representation of potential relationships between independent variables and dependant variable (green line), potential confounders and covariates potentially on the causal pathway (red text).\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-3099487/v1/3798b719d0db63eff1cab76d.png"},{"id":47146296,"identity":"6a9f0309-c6ee-4024-a98f-acd6664ca16f","added_by":"auto","created_at":"2023-11-27 15:07:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":899343,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3099487/v1/81520066-3cda-4006-b13e-d33e532bb15e.pdf"},{"id":39980289,"identity":"0070c1b9-6602-4c57-9f6b-558aca0f9bf1","added_by":"auto","created_at":"2023-07-13 14:10:45","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":14545,"visible":true,"origin":"","legend":"","description":"","filename":"Appendix.docx","url":"https://assets-eu.researchsquare.com/files/rs-3099487/v1/d357f04e92b4d41b7bdab7a4.docx"}],"financialInterests":"","formattedTitle":"The prevalence of foot pain and association with baseline characteristics in people participating in education and supervised exercise for knee or hip osteoarthritis: a cross-sectional study of 26,003 participants from the GLA:D® registry","fulltext":[{"header":"Background and rationale","content":"\u003cp\u003eOsteoarthritis (OA) is the most prevalent chronic joint disease with hip and knee OA causing the greatest burden to the population in terms of pain, stiffness and disability (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Due to a lack of effective disease modifying treatments for OA, attention has also turned to identifying modifiable risk factors to help alleviate the disease burden (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Understanding the role that clinical characteristics play in knee and hip OA is therefore important and may contribute new insight into the design, conduct or content of interventions to reduce disease burden.\u003c/p\u003e \u003cp\u003eFoot pain is highly prevalent in the general population, with estimates ranging from 13\u0026ndash;36% (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) and is notably higher in people with radiographic knee OA with estimates of around 25% (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Furthermore, the presence of foot/ankle pain in people with symptomatic radiographic knee OA has previously been shown to be associated with increased risk of worsening knee pain over time (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). However, little is known about the epidemiology of foot pain in people with symptomatic knee or hip OA, or the potential strength of association between clinical characteristics of this group and foot pain. Thus, the overall aim of this study was to estimate the prevalence of foot pain in people with knee or hip OA and to determine if baseline clinical characteristics were associated with foot pain.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eDesign, aim and context\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSecondary data analysis was conducted on cross-sectional baseline data of individuals enrolled on Good Life with osteoArthritis in Denmark (GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e). GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e was initiated in 2013 with the overarching aim of implementing clinical guidelines for the treatment of knee and hip OA in clinical practice to facilitate high quality care of people with OA in the Danish population. GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e consists of three mandatory elements: a 2-day course for physiotherapists; 8 weeks of patient education and supervised neuromuscular exercise therapy for people with knee or hip OA symptoms delivered by a certified physiotherapist in clinical practice; and data entry into the national GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e registry, with data from baseline, three and 12 month follow-up (7). Data are objectively measured, therapist-reported and patient-reported (7). This study, reported according to the STROBE guidelines for reporting cross-sectional studies (8), utilized baseline data to estimate the prevalence of foot pain in people with knee or hip OA participating in GLA:D\u003csup\u003e\u0026reg;\u0026nbsp;\u003c/sup\u003eand to determine if baseline clinical characteristics were associated with foot pain.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval and consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAccording to the ethics committee of the North Denmark Region, ethical approval of GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e was not needed. However, ethics approval for secondary analysis was received from University of Southampton Ethics and Research Online (ethics no: 56534). GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e was approved by the Danish Data Protection Agency (SDU; 10.084). According to the Danish Data Protection Act patient consent for secondary analysis was not required as personal data was processed exclusively for research and statistical purposes.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eParticipants and sampling\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants in the GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e registry have knee and/or hip joint symptoms or functional limitations associated with knee and/or hip OA that have resulted in contact with the health care system. For the current study we included individuals enrolled in GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e between 1st of July 2014 and 8th of April 2018 and who had completed a baseline pain body mannequin. Patients enrolled in GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e after this date were not included as pain mannequin data were not collected due to a database error (9\u003csup\u003eth\u003c/sup\u003e of April 2018 - 3\u003csup\u003erd\u003c/sup\u003e of November 2020). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSelf-reported, objective clinical, \u0026amp; derived outcome measures\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll independent variables were selected based\u0026nbsp;on prior research\u0026nbsp;(9,10)\u0026nbsp;or\u0026nbsp;clinical reasoning. Where it was believed other variables may introduce a confounding effect based upon clinical reasoning these were also included where available. The presence of foot pain was derived from positive indication on a 56-site body diagram (4 sites based on plantar or superior aspect of left or right feet; figure 1) indicating where the participant had experienced pain during the last 24 hours. The prevalence of foot pain was\u0026nbsp;calculated as a percentage of those with i) pain in either foot, ii) pain in both feet, or iii) pain in neither foot. Index knee and hip pain were derived from specific questions based on the most affected joint (hip or knee) and side (left or right). The prevalence of knee and hip symptoms was based on a positive indication of knee or hip joint being affected and the distribution of knee and hip symptoms based on side affected. The number of painful knee/hip joints were calculated based on a count of 1-4. Pain intensity in the worst knee/hip joint during the past month was captured (VAS 0-100) and use of pain medication in the past three months for knee or hip pain recorded (Yes/No). Current physical activity level was measured using the University of California Los Angeles (UCLA) activity score\u0026nbsp;(11), which assessed activity levels in the past 4 weeks, providing a range of levels from one (wholly inactive) to ten (very high activity). Activity levels were dichotomized as low to moderate activity (UCLA score 1\u0026ndash;6) and high activity (UCLA score 7\u0026ndash;10)(12). The presence of depression was derived from the self-reported question \u0026ldquo;Do you have a depression?\u0026rdquo; (Yes/No). Sex was derived directly from the Civil Registration number (CPR) which identifies every citizen in Denmark and age derived from a combination of the Civil Registration number (containing date of birth) and date of initiating the intervention.\u0026nbsp;Body Mass Index (BMI,\u0026nbsp;kg/m2) was calculated from height and weight assessment completed during baseline clinical visit.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eComplete case analysis was used due to the low number of missing observations (0.49%) within the main exposure variable (most affected knee/hip joint). Participants who had both outcome and exposure data available and were not missing observations from any potential confounders (age and sex) were included in the analyses. Comparisons were made between those with and without missing data for key variables.\u0026nbsp;Descriptive data for demographic characteristics and baseline foot, knee, and hip pain were calculated using means and standard deviations or frequencies.\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUnivariable and Multivariable logistic regression analysis was undertaken to calculate the strength of association between baseline clinical characteristics (including pain severity in worst knee/hip joint, number of painful knee/hip joints, pain medication use, and physical activity level) and the outcome of foot pain, in those selected for hip or knee OA. Analysis was stratified by those with index knee problems and index hip problems. Directed acyclic graphs (DAG) were used as a visual representation of associations between variables (figure 2). Multicollinearity was assessed by tolerance and variance inflation factor (VIF). All analyses were carried out in Stata 15.1 (StataCorp, College Station, TX, USA).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eOf 26,003 individuals included in this study, 74.6% (n=19,391) were enrolled with the knee as their most affected joint and 25.4% (n=6,612) with hip as the most affected joint. Of 26,003 included patients (mean age 64.83 \u0026plusmn; 9.69 years, mean BMI 28.32 \u0026plusmn; 5.26), 72.2% (n= 18,784) were registered as female, 4.4% (n=1,137) reported having depression, 63.0% (n=16,370) used pain medication, 64.3% (n=16,706) had a low to moderate ULCA score. Those patients missing data were older (mean difference of 2.5 years) and had lower knee pain intensity scores (mean difference in scores of -5.25). There was a higher percentage of females with missing data (1.2%) than males (0.9%) (see Appendix 1 for missing data table).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e**Table 1**\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIrrespective of the index joint, 83.6% (n=21,738) participants reported either left or right knee affected and 38.5% (n=10,017) reported either left or right hip affected. The prevalence of foot pain in those with knee or hip OA was 11.7% (n=3,049). Specifically, 12.4% (n=2,396) of those whose most affected joint was the knee and 9.9% (n=653) of those whose most affected joint was the hip, reported foot pain (see table 1 for distribution of foot, knee, and hip pain). Of those with left knee symptoms (n=15,328), 11.0% also had left foot pain and 11.5% with right knee symptoms (n=15,535) also had right foot pain, irrespective of index joint. Likewise, in those with left hip symptoms (n= 5,825) 10.7% (n= 624) also had left foot pain, and of those with right hip symptoms (n=6,386), 11.2% (n= 712) also had right foot pain.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAdjusted regression analysis showed that the number of painful knee/hip joints and knee/hip pain severity in the worst knee/hip joint, were significantly associated with foot pain in those with knee and hip OA, whilst taking pain medication showed association with foot pain in those with index knee OA only (table 2). Physical activity was negatively associated with foot pain; however, this relationship was attenuated within fully adjusted analysis.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e**Table 2**\u003c/strong\u003e\u003cstrong\u003e\u003cu\u003e\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe overall prevalence of foot pain in people with symptoms of knee or hip OA attending the GLA:D\u0026reg; programme was 12%, this differed slightly according to whether the index joint was knee (12%) or hip (10%). The number of other painful knee/hip joints and pain severity in worst knee/hip joint, were associated with foot pain for those with knee or hip OA. Use of pain medication was associated with foot pain in those with index knee OA only. No associations were seen for physical activity level and foot pain in either those with index knee or hip pain.\u003c/p\u003e \u003cp\u003eThe prevalence of foot pain was slightly lower than previously reported general population prevalence estimates of 13\u0026ndash;36% (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). It is possible that the use of a full body pain mannequin to estimate specific joint pain may underestimate multi-site pain prevalence. Also the definition of foot pain in GLA:D\u0026reg; was based on pain during the last 24h, which does not reflect fluctuations in foot pain over a longer period of time, nor does it consider symptoms such as aching or stiffness unlike other cohort studies (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Paterson et al (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) previously reported a notably higher prevalence of foot pain (25%) than identified in this work, in their cohort analysis of people with symptomatic radiographic knee OA, defined by frequent knee symptoms (including pain, aching, or stiffness in and around the knee on most days of the month for at least 1 month in the past year) and radiographic evidence of knee OA (Kellgren/Lawrence grade\u0026thinsp;\u0026ge;\u0026thinsp;2). The difference could be accounted for by variance in sampling strategy between studies; people were enrolled onto the GLA:D\u0026reg; programme based upon having self-reported knee/hip joint problems that resulted in contact with the Danish healthcare system, where they were assessed by the treating therapist to have symptomatic OA (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), and thus may represent a wider spectrum of disease, including those with potentially earlier pathogenesis and minimal radiographically observable change. This is the first study to determine a prevalence estimate of foot pain in those with symptomatic hip OA and as such similar comparisons cannot yet be drawn.\u003c/p\u003e \u003cp\u003eIt is unclear from cross-sectional observation alone whether foot pain precedes, coincides with, or follows the presence of symptomatic knee or hip OA. Clinically, such information could provide useful steer for future treatment targets and as such future longitudinal studies are recommended. This study has however highlighted that whilst the direction of this relationship is unclear, the odds of having foot pain is significantly increased with knee or hip pain severity and the presence of pain in more than one hip or knee joint. This highlights the importance of including foot pain measures within the clinical assessment of knee and hip symptoms, particularly in those with a diagnosis of OA. Given that it is known that people with pre-operative foot pain are more likely to have poorer clinically important outcomes following knee arthroplasty (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e), the potential for foot pain to negatively impact concurrent knee and hip symptoms and vice versa should therefore be considered.\u003c/p\u003e \u003cp\u003eParticipants of the GLA:D\u0026reg; programme with knee or hip OA symptoms and foot pain were more likely to experience worse pain intensity and pain in more sites. Furthermore, those with symptomatic knee OA and foot pain were also more likely to be using analgesic medicine. The findings reported here are consistent with similar prior observations, where worsening knee pain was associated with foot symptoms over four years in those with symptomatic radiographic knee OA (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). It is noteworthy that factors such as worsening pain have also been associated with poorer outcome or disease progression in previous studies of knee and hip OA interventions (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Arguably, based on our findings, future consideration should also be given to the effect that foot health/pain could have upon the likely success of various treatments for knee or hip OA, including exercise and surgical intervention. Future epidemiological studies could seek to build upon the data presented here to explore the wider impact of foot pain upon people living with symptomatic knee or hip OA. We may then consider the need to optimize foot health as a potentially modifiable treatment target for wider determinants of lower limb health or health-related outcomes.\u003c/p\u003e \u003cp\u003eSome of the limitations of this study have already been described. In addition, there is a potential lack of generalisability as the current study only includes those who sought education and exercise for their knee/hip OA pain, also other factors that were not accounted for may have contributed to the associations found. We do not know the reasons for foot pain, nor the longevity of its presence, and this type of information would be useful within a future longitudinal study to better understand the relationship between foot, knee, and hip symptoms.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eTwelve percent of people with knee or hip OA participating in patient education and exercise reported having foot pain, to which a range of clinical knee and hip characteristics were associated. Foot pain may therefore be an important factor to consider in the assessment of knee and hip OA. Future longitudinal epidemiological research is required to explore the natural history of foot pain in people with OA, and the potential for foot pain to be a modifiable therapeutic target to reduce disease/ symptom progression or increase treatment success.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAccording to the ethics committee of the North Denmark Region, ethical approval of GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e was not needed. However, ethics approval for secondary analysis was received from University of Southampton Ethics and Research Online (ethics no: 56534). GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e was approved by the Danish Data Protection Agency (SDU; 10.084). According to the Danish Data Protection Act patient consent for secondary analysis and reporting was not required as personal data was processed exclusively for research and statistical purposes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAccording to the Danish Data Protection Act patient consent for secondary analysis and reporting was not required as personal data was processed exclusively for research and statistical purposes. No personal identifiable data is included within this publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from S\u0026oslash;ren T. Skou [email protected] or Ewa M. Roos [email protected] but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of S\u0026oslash;ren T. Skou [email protected] or Ewa M. Roos [email protected] on behalf of the GLA:D\u0026reg; programme team.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEMR is on the Editorial Board of Osteoarthritis and Cartilage, the developer of the Knee injury and Osteoarthritis Outcome Score (KOOS) and several other patient-reported outcome measures and co-founder of GLA:D\u0026reg;, a not-for profit initiative hosted at University of Southern Denmark aimed at implementing clinical guidelines for osteoarthritis in clinical practice. EMR has received personal fees from TrustMed-Ed and Learn Physio outside the submitted work. STS is associate editor of the Journal of Orthopaedic and Sports Physical Therapy, has received personal fees from Munksgaard, TrustMe-Ed, and Nestl\u0026eacute; Health Science, outside the submitted work, and is co-founder of GLA:D\u0026reg;.\u003c/p\u003e\n\u003cp\u003eThe other authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo direct funding was obtained to undertake this research.\u003c/p\u003e\n\u003cp\u003eThe initiation of GLA:D\u0026reg; was partly funded by the Danish Physiotherapy Association\u0026rsquo;s fund for research, education and practice development; the Danish Rheumatism Association; and the Physiotherapy Practice Foundation. STS is currently funded by a program grant from Region Zealand (Exercise First) and two grants from the European Union\u0026rsquo;s Horizon 2020 research and innovation program, one from the European Research Council (MOBILIZE, grant agreement No 801790) and the other under grant agreement No 945377 (ESCAPE). These institutions had no role in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSTS, EMR, DTG contributed to the registration and conduct of the original source data. DTG contributed to the data cleaning and retrieval for this study. All authors contributed to the design, analysis, and reporting of this research. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors wish to acknowledge the participants of the GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e study for their time and contribution to data collection and the staff and volunteers involved in the delivery and running of the GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e programme.\u003c/p\u003e\n\u003cp\u003eFor the purpose of open access, the author has applied a Creative Commons attribution license (CC BY) to any Author Accepted Manuscript version arising from this submission.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLitwic A, Edwards MH, Dennison EM, Cooper C. Epidemiology and burden of osteoarthritis. British Medical Bulletin. 2013;105(1):185-99.\u003c/li\u003e\n\u003cli\u003eGr\u0026auml;ssel S, Muschter D. Recent advances in the treatment of osteoarthritis. F1000Res. 2020;9:F1000 Faculty Rev-325.\u003c/li\u003e\n\u003cli\u003eGeorgiev T, Angelov AK. Modifiable risk factors in knee osteoarthritis: treatment implications. Rheumatology International. 2019;39(7):1145-57.\u003c/li\u003e\n\u003cli\u003eGates LS, Arden NK, Hannan MT, Roddy E, Gill TK, Hill CL, et al. Prevalence of Foot Pain Across an International Consortium of Population-Based Cohorts. Arthritis Care Res (Hoboken). 2019;71(5):661-70.\u003c/li\u003e\n\u003cli\u003ePaterson KL, Hinman RS, Hunter DJ, Wrigley TV, Bennell KL. Impact of concurrent foot pain on health and functional status in people with knee osteoarthritis: data from the osteoarthritis initiative. Arthritis care \u0026amp; research. 2015;67(7):989-95.\u003c/li\u003e\n\u003cli\u003ePaterson KL, Kasza J, Hunter DJ, Hinman RS, Menz HB, Peat G, et al. Longitudinal association between foot and ankle symptoms and worsening of symptomatic radiographic knee osteoarthritis: data from the osteoarthritis initiative. Osteoarthritis Cartilage. 2017;25(9):1407-13.\u003c/li\u003e\n\u003cli\u003eSkou ST, Roos EM. Good Life with osteoArthritis in Denmark (GLA:D\u0026trade;): evidence-based education and supervised neuromuscular exercise delivered by certified physiotherapists nationwide. BMC Musculoskeletal Disorders. 2017;18(1):72.\u003c/li\u003e\n\u003cli\u003evon Elm E, Altman DG, Egger M, Pocock SJ, G\u0026oslash;tzsche PC, Vandenbroucke JP; STROBE Initiative.\u003cstrong\u003eThe Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)statement: guidelines for reporting observational studies.\u003c/strong\u003e J Clin Epidemiol. 2008 Apr;61(4):344-9. PMID: 18313558\u003c/li\u003e\n\u003cli\u003eHill CL, Gill TK, Menz HB, Taylor AW. Prevalence and correlates of foot pain in a population-based study: the North West Adelaide health study. Journal of foot and ankle research. 2008;1(1):2.\u003c/li\u003e\n\u003cli\u003eAwale A, Dufour AB, Katz P, Menz HB, Hannan MT. Link Between Foot Pain Severity and Prevalence of Depressive Symptoms. Arthritis care \u0026amp; research. 2016;68(6):871-6.\u003c/li\u003e\n\u003cli\u003eZahiri CA, Schmalzried TP, Szuszczewicz ES, Amstutz HC. Assessing activity in joint replacement patients. The Journal of arthroplasty. 1998;13(8):890-5.\u003c/li\u003e\n\u003cli\u003eL\u0026uuml;bbeke A, Zimmermann-Sloutskis D, Stern R, Roussos C, Bonvin A, Perneger T, et al. Physical Activity Before and After Primary Total Hip Arthroplasty: A Registry-Based Study. Arthritis Care \u0026amp; Research. 2014;66(2):277-84.\u003c/li\u003e\n\u003cli\u003eGates LS, Bowen CJ, Sanchez-Santos MT, Delmestri A, Arden NK. Do foot \u0026amp;amp; ankle assessments assist the explanation of 1 year knee arthroplasty outcomes? Osteoarthritis and Cartilage. 2017;25(6):892-8.\u003c/li\u003e\n\u003cli\u003eBirch S, Stilling M, Mechlenburg I, Hansen TB. The association between pain catastrophizing, physical function and pain in a cohort of patients undergoing knee arthroplasty. BMC Musculoskeletal Disorders. 2019;20(1):421.\u003c/li\u003e\n\u003cli\u003eJudge A, Arden NK, Cooper C, Kassim Javaid M, Carr AJ, Field RE, et al. Predictors of outcomes of total knee replacement surgery. Rheumatology. 2012;51(10):1804-13.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1. Presence and distribution of foot, knee, and hip pain, stratified by index joint\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" align=\"left\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003eIndex knee Pain\u003c/p\u003e\n \u003cp\u003e(n=19,391)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003eIndex hip pain\u003c/p\u003e\n \u003cp\u003e(n=6,612)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003eFoot pain presence, n (%) Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e2,396 (12.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e653 (9.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003eFoot pain distribution\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eLeft *\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e1,947 (10.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e524 (7.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003e*not exclusive to one side\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eRight *\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e1,986 (10.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e523 (7.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eLeft (unilateral)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e410 (2.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e130 (2.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eRight (unilateral)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e449 (2.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e129 (2.0) \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eBilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e1537 (7.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e394 (6.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eEither foot\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e2,396 (12.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e653 (9.9) \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003eMost affected joint side, n (%) Right \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e10,104 (52.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e3,581 (54.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" valign=\"top\"\u003e\n \u003cp\u003eKnee/Hip pain severity, mean (SD), VAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e48.12 (22.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e48.10 (21.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" rowspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003eKnee pain distribution, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e5,140 (26.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e1,063 (16.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e5,457 (28.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e953 (14.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eBilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e8,794 (45.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e331 (5.01)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eNo Knee pain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e4,265 (64.50)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" rowspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003eHip pain distribution, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e1,373 (7.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e2,258 (34.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e1,521 (7.84)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e2,671 (40.40)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eBilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e511 (2.64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e1,683 (25.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eNo Hip pain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e15,986 (82.44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"45.590682196339436%\" rowspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003eNumber of knee/hip joints affected, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\" valign=\"top\"\u003e\n \u003cp\u003eOne\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.80199667221298%\" valign=\"top\"\u003e\n \u003cp\u003e8,080 (41.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.302828618968388%\" valign=\"top\"\u003e\n \u003cp\u003e2,922 (44.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eTwo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e10,284 (53.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e3,188 (48.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eThree\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e655 (3.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e333 (5.04)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.804281345565748%\" valign=\"top\"\u003e\n \u003cp\u003eFour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.5565749235474%\" valign=\"top\"\u003e\n \u003cp\u003e372 (1.92)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.63914373088685%\" valign=\"top\"\u003e\n \u003cp\u003e169 (2.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003c/strong\u003e\u003cstrong\u003eTable 2. Associations between foot pain and baseline characteristics based in adjusted multivariable models\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.285714285714286%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"42.857142857142854%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eIndex knee (n= 19,391)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"42.857142857142854%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eIndex hip (n=6,612)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.285714285714286%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.428571428571427%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eUnivariable\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.428571428571427%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMultivariable\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.428571428571427%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eUnivariable\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.428571428571427%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMultivariable\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.262023217247098%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.262023217247098%\" valign=\"top\"\u003e\n \u003cp\u003eNumber of painful knee/hip joints\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.65, \u0026nbsp; \u0026nbsp;1.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.58, 1.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.55, \u0026nbsp; 1.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.48, \u0026nbsp; \u0026nbsp;1.83\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.262023217247098%\" valign=\"top\"\u003e\n \u003cp\u003eKnee/hip pain severity in worst knee/hip joint\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.01, \u0026nbsp; \u0026nbsp; 1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.00, 1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.01, 1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.01, \u0026nbsp; \u0026nbsp; 1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.262023217247098%\" valign=\"top\"\u003e\n \u003cp\u003eUse of pain medication for knee/hip\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.35, \u0026nbsp; \u0026nbsp;1.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.12, 1.36\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.09, \u0026nbsp; 1.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e0.89, \u0026nbsp; \u0026nbsp; 1.29\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.262023217247098%\" valign=\"top\"\u003e\n \u003cp\u003ePhysical activity level\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e0.92, 0.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e0.97, 1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.613598673300165%\" valign=\"top\"\u003e\n \u003cp\u003e0.90, 0.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.779436152570481%\" valign=\"top\"\u003e\n \u003cp\u003e0.95, \u0026nbsp; \u0026nbsp;1.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-foot-and-ankle-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jfar","sideBox":"Learn more about [Journal of Foot and Ankle Research](http://jfootankleres.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/jfar/default.aspx","title":"Journal of Foot and Ankle Research","twitterHandle":"@jfootankleres","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"osteoarthritis, knee, hip, foot, pain, cross-sectional","lastPublishedDoi":"10.21203/rs.3.rs-3099487/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3099487/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eOsteoarthritis (OA) affecting the knee or hip is highly prevalent in the general population and has associated high disease burden. Early identification of modifiable risk factors that prevent, limit, or resolve disease symptoms is critical. Foot pain may represent a potentially modifiable factor however little is known about the prevalence of foot pain in people with knee or hip OA nor whether foot pain is associated with clinical characteristics. The main aim of this study was therefore to determine the prevalence of foot pain in people with knee or hip OA attending an education and supervised exercise-based intervention in Denmark (GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e) and determine if baseline demographic or clinical characteristics are associated with foot pain.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eAnalysis was conducted on baseline data of 26,003 people with symptomatic knee or hip OA completing a body mannequin as part of the Good Life with osteoArthritis in Denmark (GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e) primary care programme. Odds Ratios (OR) and 95% confidence intervals (CI) were calculated to estimate the strength of association between baseline clinical characteristics (including pain severity in worst knee/hip joint, number of painful knee/hip joints, pain medication use and physical activity level) and the presence of baseline foot pain.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eTwelve percent of participants (n\u0026thinsp;=\u0026thinsp;3,049) reported foot pain. In those people with index knee OA (n\u0026thinsp;=\u0026thinsp;19,391), knee pain severity (OR 1.01 CI 1.00, 1.01), number of painful knee/hip joints (OR 1.67 CI 1.58, 1.79), and use of pain medication (OR 1.23 CI 1.12, 1.36) were statistically associated with foot pain. Excluding use of pain medication, similar associations were seen in those with index hip OA.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eTwelve percent of people with knee or hip OA participating in GLA:D\u003csup\u003e\u0026reg;\u003c/sup\u003e had foot pain. Those with worse knee/hip pain, and greater number of painful joints were more likely to report foot pain. This study is the first to demonstrate a significant relationship between clinical characteristics and foot pain in people with knee or hip OA participating in education and supervised exercise. Future investigation should consider the role that foot pain may play on knee and hip related outcomes following therapeutic intervention.\u003c/p\u003e","manuscriptTitle":"The prevalence of foot pain and association with baseline characteristics in people participating in education and supervised exercise for knee or hip osteoarthritis: a cross-sectional study of 26,003 participants from the GLA:D® registry","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-07-13 14:10:41","doi":"10.21203/rs.3.rs-3099487/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2023-07-09T11:17:46+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-07-09T11:14:19+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2023-07-09T00:00:00+00:00","index":1,"fulltext":""},{"type":"editorAssigned","content":"","date":"2023-07-06T03:03:36+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-07-04T23:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2023-07-04T23:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Foot and Ankle Research","date":"2023-06-25T16:53:42+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-foot-and-ankle-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jfar","sideBox":"Learn more about [Journal of Foot and Ankle Research](http://jfootankleres.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/jfar/default.aspx","title":"Journal of Foot and Ankle Research","twitterHandle":"@jfootankleres","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c1cd7e74-5cd8-4330-a900-dc62cac54f3d","owner":[],"postedDate":"July 13th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-11-27T15:03:48+00:00","versionOfRecord":{"articleIdentity":"rs-3099487","link":"https://doi.org/10.1186/s13047-023-00673-5","journal":{"identity":"journal-of-foot-and-ankle-research","isVorOnly":false,"title":"Journal of Foot and Ankle Research"},"publishedOn":"2023-11-23 15:00:49","publishedOnDateReadable":"November 23rd, 2023"},"versionCreatedAt":"2023-07-13 14:10:41","video":"","vorDoi":"10.1186/s13047-023-00673-5","vorDoiUrl":"https://doi.org/10.1186/s13047-023-00673-5","workflowStages":[]},"version":"v1","identity":"rs-3099487","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3099487","identity":"rs-3099487","version":["v1"]},"buildId":"-HB7Z8yhvgn0wM9Nzuekk","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}