Review Article| Volume 152, P13-22, December 2022

Almost one in five physiotherapy trials excluded people due to lack of language proficiency: A meta-epidemiological study

Published:September 20, 2022DOI:



      The objective of the study was to examine the characteristics of randomized controlled trials (RCTs) evaluating physiotherapy interventions for low back pain (LBP) that specified a language-grounded eligibility criterion and the proportion of people being excluded consequently.

      Study Design and Setting

      This is a meta-epidemiological study of RCTs evaluating at least one type of physiotherapy intervention for treatment or prevention of LBP. Records were retrieved from Physiotherapy Evidence Database (PEDro), LILACS, and SciELO from inception to May 2021. We retrieved metadata of each record from PEDro and extracted from included studies: country of recruitment, language-grounded eligibility criterion, and the number of consequent exclusions (if specified).


      This study included 2,555 trials. A language-grounded eligibility criterion was specified in 463 trials (18.1%); the proportion was higher in trials conducted in North America and Europe, published after 2000, investigating cognitive and behavioral interventions, and including large sample size. Of these 463 trials, 75 trials (16.2%) reported a total number of 2,152 people being excluded due to lack of language proficiency, equivalent to 12.5% of randomized participants.


      Nearly one in five physiotherapy clinical trials on LBP excludes people based on language proficiency, compromising the evidence to manage LBP in minority populations.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of Clinical Epidemiology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Hartvigsen J.
        • Hancock M.J.
        • Kongsted A.
        • Louw Q.
        • Ferreira M.L.
        • Genevay S.
        • et al.
        What low back pain is and why we need to pay attention.
        Lancet. 2018; 391: 2356-2367
        • GBD 2019 Diseases and Injuries Collaborators
        Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019.
        Lancet. 2020; 396: 1204-1222
        • Cieza A.
        • Causey K.
        • Kamenov K.
        • Hanson S.W.
        • Chatterji S.
        • Vos T.
        Global estimates of the need for rehabilitation based on the global burden of disease study 2019: a systematic analysis for the global burden of disease study 2019.
        Lancet. 2021; 396: 2006-2017
        • Henschke N.
        • Lorenz E.
        • Pokora R.
        • Michaleff Z.A.
        • Quartey J.N.A.
        • Oliveira V.C.
        Understanding cultural influences on back pain and back pain research.
        Best Pract Res Clin Rheumatol. 2016; 30: 1037-1049
        • Hoy D.
        • Bain C.
        • Williams G.
        • March L.
        • Brooks P.
        • Blyth F.
        • et al.
        A systematic review of the global prevalence of low back pain.
        Arthritis Rheum. 2012; 64: 2028-2037
        • Volinn E.
        The epidemiology of low back pain in the rest of the world. A review of surveys in low- and middle-income countries.
        Spine (Phila Pa 1976). 1997; 22: 1747-1754
      1. Population by income level, 1960 to 2017- total population, differentiated by World Bank income level. Our World in Data website.
        (Available at)
        • Hughson J.A.
        • Woodward-Kron R.
        • Parker A.
        • Hajek J.
        • Bresin A.
        • Knoch U.
        • et al.
        A review of approaches to improve participation of culturally and linguistically diverse populations in clinical trials.
        Trials. 2016; 17: 263
        • United States Census Bureau
        Selected characteristics of the native and foreign-born populations. 2019: ACS 1-year estimates subject tables (S0501).
        (Available at)
        • Gambino C.P.
        • Acosta Y.D.
        • Grieco E.M.
        English-speaking ability of the foreign-born population in the United States: 2012. U.S. Census Bureau- American Community Survey Reports. website.
        (Available at)
        • Australian Bureau of Statistics
        Cultural diversity in Australia, 2016. 2071.0 - census of population and housing: reflecting Australia - stories from the census, 2016.
        (Available at)
        • Stanaway F.
        • Cumming R.G.
        • Blyth F.
        Exclusions from clinical trials in Australia based on proficiency in English.
        Med J Aust. 2017; 207: 36
        • Muthukumar A.V.
        • Morrell W.
        • Bierer B.E.
        Evaluating the frequency of English language requirements in clinical trial eligibility criteria: a systematic analysis using
        PLoS Med. 2021; 18: e1003758
        • Brodeur M.
        • Herrick J.
        • Guardioloa J.
        • Richman P.
        Exclusion of non-English speakers in published emergency medicine research - a comparison of 2004 and 2014.
        Acta Inform Med. 2017; 25: 112-115
        • Murray S.
        • Buller A.M.
        Exclusion on grounds of language ability--a reporting gap in health services research?.
        J Health Serv Res Policy. 2007; 12: 205-208
        • Oliveira C.B.
        • Maher C.G.
        • Pinto R.Z.
        • Traeger A.C.
        • Lin C.W.C.
        • Chenot J.F.
        • et al.
        Clinical practice guidelines for the management of non-specific low back pain in primary care: an updated overview.
        Eur Spine J. 2018; 27: 2791-2803
        • Chou R.
        • Cote P.
        • Randhawa K.
        • Torres P.
        • Yu H.
        • Nordin M.
        • et al.
        The Global Spine Care Initiative: applying evidence-based guidelines on the non-invasive management of back and neck pain to low- and middle-income communities.
        Eur Spine J. 2018; 27: 851-860
        • Cashin A.G.
        • Lee H.
        • Bagg M.K.
        • O’Hagan E.
        • Traeger A.C.
        • Kamper S.J.
        • et al.
        A systematic review highlights the need to improve the quality and applicability of trials of physical therapy interventions for low back pain.
        J Clin Epidemiol. 2020; 126: 106-115
        • Page M.J.
        • McKenzie J.E.
        • Bossuyt P.M.
        • Boutron I.
        • Hoffmann T.C.
        • Mulrow C.D.
        • et al.
        The PRISMA 2020 statement: an updated guideline for reporting systematic reviews.
        BMJ. 2021; 372: n71
        • Michaleff Z.A.
        • Costa L.O.
        • Moseley A.M.
        • Maher C.G.
        • Elkins M.R.
        • Herbert R.D.
        • et al.
        CENTRAL, PEDro, PubMed, and EMBASE are the most comprehensive databases indexing randomized controlled trials of physical therapy interventions.
        Phys Ther. 2011; 91: 190-197
        • Moseley A.M.
        • Elkins M.R.
        • Van der Wees P.J.
        • Pinheiro M.B.
        Using research to guide practice: the physiotherapy evidence database (PEDro).
        Braz J Phys Ther. 2020; 24: 384-391
        • Physiotherapy Evidence Database (PEDro)
        Learn - frequently asked questions.
        (Available at)
        • Physiotherapy Evidence Database (PEDro)
        PEDro indexing criteria and codes.
        (Available at)
        • Physiotherapy Evidence Database (PEDro)
        PEDro scale.
        (Available at)
        Date: 1999
        Date accessed: April 20, 2021
      2. DeCS/MeSH health sciences descriptors. BIREME Latin American and caribbean center on health sciences information.
        (Available at)
        Date accessed: January 19, 2020
      3. World health statistics 2021: monitoring health for the SDGs, sustainable development goals. Geneva: World Health Organization; 2021. Annex 3: WHO Regional Groupings. pp117.

        • Isaacs T.
        • Hunt D.
        • Ward D.
        • Rooshenas L.
        • Edwards L.
        The inclusion of ethnic minority patients and the role of language in telehealth trials for type 2 diabetes: a systematic review.
        J Med Internet Res. 2016; 18: e256
        • Koes B.W.
        • Malmivaara A.
        • van Tulder M.W.
        Trend in methodological quality of randomised clinical trials in low back pain.
        Best Pract Res Clin Rheumatol. 2005; 19: 529-539
        • Koes B.W.
        • Bouter L.M.
        • van der Heijden G.J.
        Methodological quality of randomized clinical trials on treatment efficacy in low back pain.
        Spine (Phila Pa 1976). 1995; 20: 228-235
        • Antoniou S.A.
        • Andreou A.
        • Antoniou G.A.
        • Koch O.O.
        • Kohler G.
        • Luketina R.R.
        • et al.
        Volume and methodological quality of randomized controlled trials in laparoscopic surgery: assessment over a 10-year period.
        Am J Surg. 2015; 210: 922-929
        • Ahmed Ali U.
        • van der Sluis P.C.
        • Issa Y.
        • Habaga I.A.
        • Gooszen H.G.
        • Flum D.R.
        • et al.
        Trends in worldwide volume and methodological quality of surgical randomized controlled trials.
        Ann Surg. 2013; 258: 199-207
        • United Nations Department of Economic and Social Affairs, Population Division
        International migrant stock 2020.
        (Available at)
      4. McAuliffe M. Triandafyllidou A. World migration report 2022. International Organization for Migration (IOM), Geneva2021 (Available at)
        • Hajihasani A.
        • Rouhani M.
        • Salavati M.
        • Hedayati R.
        • Kahlaee A.H.
        The influence of cognitive behavioral therapy on pain, quality of life, and depression in patients receiving physical therapy for chronic low back pain: a systematic review.
        PM R. 2019; 11: 167-176
        • Moseley A.M.
        • Herbert R.D.
        • Maher C.G.
        • Sherrington C.
        • Elkins M.R.
        Reported quality of randomized controlled trials of physiotherapy interventions has improved over time.
        J Clin Epidemiol. 2011; 64: 594-601
        • O’Sullivan P.B.
        • Caneiro J.P.
        • O’Keeffe M.
        • Smith A.
        • Dankaerts W.
        • Fersum K.
        • et al.
        Cognitive functional therapy: an integrated behavioral approach for the targeted management of disabling low back pain.
        Phys Ther. 2018; 98: 408-423
        • Frayne S.M.
        • Burns R.B.
        • Hardt E.J.
        • Rosen A.K.
        • Moskowitz M.A.
        The exclusion of non-English-speaking persons from research.
        J Gen Intern Med. 1996; 11: 39-43
        • Innocenti T.
        • Giagio S.
        • Salvioli S.
        • Feller D.
        • Minnucci S.
        • Brindisino F.
        • et al.
        Completeness of reporting is suboptimal in randomized controlled trials published in rehabilitation journals, with trials with low risk of bias displaying better reporting: a meta-research study.
        Arch Phys Med Rehabil. 2022; 103: 1839-1847