Pre-rehabilitation scores of functioning measured using the World Health Organization Disability Assessment Schedule in persons with nonspecific low back pain: a scoping review

Abstract

Knowledge of the pre-rehabilitation generic status of functioning in individuals with low back pain is necessary to understand the clinical utility of rehabilitation care. We conducted a scoping review to describe the pre-rehabilitation functioning status of persons with nonspecific low back pain using the World Health Organization Disability Assessment Schedule (WHODAS)-36 or WHODAS-12. We searched multiple databases from 2010 to 2021 for studies reporting pre-rehabilitation scores using WHODAS in persons with low back pain. Reviewers independently screened articles and extracted data, and we descriptively summarized results by the duration of low back pain (acute/subacute <3 months; chronic ≥3 months), and the WHODAS version. Of 1770 citations screened, eight citations were relevant. Five studies were conducted in Europe, two in America, and one in the African Region (mostly high-income countries). In persons with acute low back pain, the mean WHODAS-36 pre-rehabilitation summary score (complex scoring) was 22.8/100 (SD = 15.4) (one study). In persons with chronic low back pain, the mean WHODAS-36 summary score (complex scoring) ranged from 22.8/100 (SD = 5.7) to 41.5/100 (SD = 13.8) (two studies). For WHODAS-12 in persons with chronic low back pain, the mean summary score was 11.4/48 (SD = 8.7) or 14.4/48 (SD = 9.4) using simple scoring (two studies), and 25.8/100 (SD = 2.2) using complex scoring (one study). No floor or ceiling effects were observed in WHODAS-36 summary scores for chronic low back pain. Our scoping review comprehensively summarizes available studies reporting pre-rehabilitation levels of functioning using WHODAS in persons with low back pain. Persons with low back pain seeking rehabilitation have moderate limitations in functioning, and limitations level tends to be worse with chronic low back pain.

Introduction

The global need for rehabilitation is high, increasing over time and largely unmet; many people who require rehabilitation are not receiving these services, particularly in low- and middle-income countries and remote communities [1,2]. The World Health Organization (WHO) issued a call to increase access to rehabilitation services globally by strengthening the health system for rehabilitation [3]. Low back pain (LBP) is the main reason for unmet rehabilitation needs globally [1,4]. It is thus critically important that people with LBP receive rehabilitation services to improve functioning and health.

Knowledge of the pre-rehabilitation overall status of functioning in individuals with LBP is necessary to understand the clinical utility of rehabilitation care. It is also important to measure whether the delivery of rehabilitation services effectively improves functioning at individual and population levels. To assess whether rehabilitation is effective, we need to analyze the pre-rehabilitation level of functioning in persons with LBP, and determine whether rehabilitation achieves a threshold of important benefit. The distribution and mean scores of the overall status of functioning in persons seeking rehabilitation for LBP are unclear.

Various instruments have the potential to assess pre-rehabilitation levels of functioning, including generic and condition-specific instruments. Most commonly used condition-specific instruments may not fully capture all constructs of functioning as per the International Classification of Functioning, Disability and Health (ICF) [5], and it is recommended that measurement of rehabilitation outcomes be based on the ICF [6]. This is particularly relevant in adults with chronic LBP as a complex condition with multiple contributors to disability, including psychological, social and biophysical factors, and comorbidities [7]. Moreover, generic measures of functioning [e.g. WHO Disability Assessment Schedule (WHODAS), Patient-Reported Outcomes Measurement Information System (PROMIS)] can be more useful than condition-specific instruments for measuring functioning related to chronic LBP in the population. Generic measures do not target specific diseases or etiology, providing a common metric of the impact of any health condition or general health on functioning. We selected WHODAS because it is a self-reported questionnaire developed by the WHO as a generic tool that integrates an individual’s level of functioning in major life domains, and is directly linked to ICF concepts [8]. The WHODAS is brief, applicable across various cultures and settings, and easy to administer in clinical and population-based settings [8]. As a generic measure of functioning, the WHODAS allows knowledge users to assess functioning levels in the general population and across specific groups, including different physical and mental conditions [8].

In collaboration with the WHO Rehabilitation Programme, we conducted two reviews to inform the development of a global indicator of effective coverage for LBP rehabilitation. First, a systematic review was conducted to synthesize the evidence on the measurement properties and minimal important change of WHODAS for LBP [9]. Second, we conducted this scoping review to establish pre-rehabilitation data of functioning using WHODAS in persons with LBP, which will be used to calculate the effects of rehabilitation in the population. The research question was: What is the distribution of pre-rehabilitation scores of functioning measured using the WHODAS-36 or WHODAS-12 in persons with nonspecific LBP?

Methods

The scoping review protocol was registered with the Open Science Framework Registries on 15 June 2021 (https://doi.org/10.17605/OSF.IO/GQYVB). The scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews statement [10]. To guide the conduct of this scoping review, we followed the 6-stage framework outlined by Arksey and O’Malley and advanced by Levac et al. and others [11–13]. This framework involves: (1) identifying the research question; (2) identifying relevant studies; (3) study selection; (4) charting data; (5) collating, summarizing, and reporting the results and (6) consultation exercise.

Stage 1: identifying the research question

As previously stated, our scoping review was guided by the following research question: What is the distribution of pre-rehabilitation scores of functioning measured using the WHODAS-36 or WHODAS-12 in persons with nonspecific LBP?

Stage 2: identifying relevant studies

The search strategy was developed with an experienced librarian, which was reviewed by a second librarian using the Peer Review of Electronic Search Strategies Checklist [14] (see Supplementary Appendix I, Supplemental digital content 1, http://links.lww.com/IJRR/A26, which lists the search strategies). MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), APA PsycInfo (Ovid), EBSCO Discovery Service, and Cochrane Central Register of Controlled Trials were searched from 1 January 2010 to 22 June 2021. The search included subject headings (e.g. MeSH in MEDLINE) and free text words related to spinal pain and WHODAS. The search strategy was first developed in MEDLINE and adapted to other bibliographic databases. EndNote was used to de-duplicate references electronically. A supplemental search of a related systematic review (assessing the psychometric properties or minimal important change of WHODAS in persons with LBP [9]) was conducted to identify any other relevant studies (see Supplementary Appendix II, Supplemental digital content 1, http://links.lww.com/IJRR/A26, which lists the supplemental search).

Stage 3: study selection

Population

Studies of persons with nonspecific LBP were included. Nonspecific LBP is defined as pain between the costal margin and inferior gluteal folds with or without leg pain in the absence of underlying serious or major pathology (e.g. fractures, dislocations, spinal cord injury, inflammatory arthritides, neoplasms, malignancies, any other serious pathology from trauma or deformities) [15]. Studies targeting musculoskeletal conditions or spinal pain were included if WHODAS scores were stratified for LBP. Studies were excluded if they targeted major neuromusculoskeletal or connective tissue disorders, autoimmune disorders, congenital disorders, major trauma (e.g. with serious pathology) or deformities.

Instrument

The WHODAS 2.0 is a generic, self-reported assessment instrument developed by the WHO to provide a standardized method for measuring functioning across different health conditions, cultures and settings [8]. We included the WHODAS-36 and WHODAS-12 questionnaires, including simple and complex scoring, and summary and domain scores of the WHODAS [8]. Simple scoring involves adding up the scores from each WHODAS item without recoding or collapsing response categories; thus, there is no weighting of individual items [8]. Complex scoring involves item response theory-based scoring, which accounts for multiple levels of difficulty for each WHODAS item, using an algorithm to determine the summary score by differentially weighting the items and levels of severity [8].

Rehabilitation

The WHO defines rehabilitation as a set of interventions designed to optimize functioning and reduce disability in individuals with health conditions in interaction with their environment [2]. Examples of interventions for the rehabilitation of LBP include education, medication, physical exercise, manual therapies, acupuncture, electro-physical modalities, psychological therapies, home or workplace adaptations, interventions for return to work and injections. We included studies that did not describe an intervention or were conducted in the general population to represent persons who may seek rehabilitation. Surgical procedures were excluded (e.g. discectomy, spinal decompression, fusion, disc replacement and surgeries for fractures, major trauma or deformities) to focus on noninvasive interventions and rehabilitation services in this review.

In addition to the above criteria, eligible studies met the following: (1) published in English, French, Farsi, Chinese, German, Greek, Swedish or Italian languages (to increase the feasibility of conducting the review) and (2) randomized trials, cohort studies and cross-sectional studies that report pre-rehabilitation scores using WHODAS-36 or WHODAS-12 in persons with nonspecific LBP. Cohort and cross-sectional studies conducted in all settings were eligible, including population-based, clinical and hospital settings. The following were excluded during screening: (1) guidelines, letters, editorials, commentaries, government reports, books and book chapters, conference proceedings, meeting abstracts, lectures and addresses, consensus development statements, guideline statements, studies not reporting on methodology and (2) systematic reviews, literature reviews and case studies.

A two-phase screening process (titles/abstracts and full-text screening) was used to select eligible studies. The pilot screening was conducted with a random sample of citations (50 titles/abstracts) using predefined inclusion and exclusion criteria to review any disagreements with reviewers before starting screening. Pairs of trained reviewers independently screened articles in phase I (titles/abstracts) and phase II (full text) to identify relevant studies (J.J.W., A.D., H.V., S.M., P.S., D.S., S.A., M.B., N.L. and P.C.). Reviewers met to discuss disagreements and reach a consensus on the eligibility of studies. A third reviewer was involved if consensus could not be reached. Study authors were contacted for additional information as needed during citation screening and data extraction of studies.

Stage 4: charting data

A reviewer extracted all data from eligible studies to build evidence tables. The WHODAS scores were independently extracted by a second reviewer and discussed to reach a consensus. For all other data items (e.g. population characteristics, instrument administration), a second reviewer verified the data extraction items by checking the extracted data. Data were extracted from each study on the author, year, study design, setting and participants, instrument and pre-rehabilitation scores of the WHODAS (e.g. mean, SD, median, interquartile range, range, ceiling and floor effects). All available data were extracted on the distribution and mean scores of WHODAS reported in relevant studies.

Stage 5: collating, summarizing, and reporting the results

The kappa of the agreement for citation screening was computed. Based on charted data, pre-rehabilitation WHODAS scores were summarized by the duration of LBP (acute/subacute: <3 months versus chronic: ≥3 months), WHODAS questionnaire (WHODAS-36 versus WHODAS-12) and scoring method (simple versus complex scoring). We described the main areas of research and provided simple frequency counts of studies under the following categories [16]: (1) duration of LBP (acute/subacute or chronic), (2) WHODAS questionnaire (WHODAS-36 or WHODAS-12; language), (3) geographical location (WHO region; low-, middle- or high-income country).

Stage 6: consultation exercise

This scoping review was conducted in collaboration with the WHO Rehabilitation Programme as the main knowledge user. With regular meetings throughout the project, the WHO was involved in developing the research question and methodology, interpreting findings, drafting key messages and disseminating results.

Results

Study selection

We screened 1770 titles and abstracts in phase 1 and 225 full texts in phase 2 (Fig. 1). Of these, eight relevant studies provided pre-rehabilitation WHODAS scores in persons with LBP. Pilot screening achieved 82% (titles/abstracts) and 80% (full-texts) agreement before discussion to reach consensus. The inter-rater agreement for screening before the discussion to reach consensus was 91% agreement, kappa = 0.56, 95% confidence interval (CI), 0.51–0.62. We contacted the authors of three studies [17–19] during data extraction for clarification on study methodology or WHODAS scores, and all responded with additional information.

Fig. 1.

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) flow diagram for scoping reviews showing identification and selection of included studies. LBP, low back pain; WHODAS, World Health Organization Disability Assessment Schedule.

Descriptive numerical analysis

Of the eight included studies, five studies utilized WHODAS-36 [17,19–22] and three utilized WHODAS-12 [18,23,24] (Table 1). Four studies used a non-English version of WHODAS (Polish, Igbo, Portuguese, Italian and German language) [17,19,21,24]. The proportions of women in study populations ranged from 42% to 67% and the mean age ranged from 45 to 71 years. Study populations included acute LBP (one study) [20], chronic LBP (six studies) [17–19,21,23,24], and LBP with duration not specified (one study) [22]. Five studies were conducted in the European region [17,21–24], two studies in the region of the Americas [18,20] and one study in the African region [19]. Seven out of eight studies were conducted in high-income countries [17,18,20–24]. Seven studies were conducted in clinical or rehabilitation settings [17,19–24], whereas one study was conducted in the general population [18].

Table 1.

Data extraction table for scoping review on prerehabilitation functioning scores measured using the WHO Disability Assessment Schedule (WHODAS) in persons with low back pain

	Population				Instrument administration						Functioning score measured using WHODAS
Author, year, study design	N	Age in years, mean (SD, range)	Sex (% female)	Health condition, duration (mean, SD)	Setting	Country, WHO region, low/middle/high-income country	Version of instrument, language	Response rate	Mode of administrationa	Scoring methodb
Acute/subacute LBP
Chwastiak et al. (2003), cohort study [20]	76	44.6 (range 22–61)	42.0%	Acute episode of LBP; no diagnosis of LBP in preceding 120 days	Primary care setting	United States; region of the Americas; high-income	WHODAS-36; language not specified	Follow-up rate: 90.7% for follow-up interviews at 3 months	Telephone interview	Summary and domain scores; complex scoring; 0–100 scale	Total score: Baseline, mean (SD): 22.75 (15.4) 3-month follow-up, mean: 13.49
Chronic LBP
Bärlund et al. (2021), cross-sectional study [23]	1379	47.6 (14.9)	64%	Chronic LBP; Diagnoses of M (Musculoskeletal system) 92%; of which 50% had M54 (Dorsalgia); chronic duration not specified	Outpatient physical and rehabilitation medicine clinic at a university hospital	Finland; European region; high-income	WHODAS-12; language not specified	Response rate 44% (for those who completed both ODI and WHODAS)	Self-administered	Summary scores; simple scoring; 0–48 scale	Total score: Mean (SD) 14.4 (9.4)
Csupak et al. (2018), cross-sectional study [18]	25 113 (entire study sample); 5205 (back pain specific)	48.5 (SE 0.1)	50.7%	18.1% of entire sample with back pain; chronic duration ≥6 months	Not reported	Canada; region of the Americas; high-income	WHODAS-12; language not specified	Response rate 86.3% (entire sample)	Administered by trained lay interviewers	Summary scores; complex scoring; 0–100 scale	Total score: Mean (SE): 25.80 (2.22)
Cwirlej-Sozanska et al. (2020), cohort study [21]	92	66.0 (11.6)	62.0	Chronic LBP (≥12 weeks)	Hospital rehabilitation ward	Poland; European region; high-income	WHODAS-36; Polish	Participation rate study I: 87.6%; follow-up rate for study II: 94.6%; follow-up for study III: 74.7%	Direct interview implementing a pen and paper interview method (self-reported questionnaire)	Summary and domain scores; complex scoring; 0-100 scale	Total score: Mean (SD):41.53 (13.84) No floor or ceiling effects observed in the total score
Gonçalves Silva et al. (2016), cross-sectional analysis of cohort study [24]	504	70.9 (7.5)	67.1%	Chronic conditions; LBP (n = 206) 54.8% of entire sample; LBP duration <6 months (n = 16) 7.7%, ≥6 months (n = 190) 92.3%	Primary healthcare practices	Portugal; European region; high-income	WHODAS-12; Portuguese	Participation rate not reported	Interview-based	Summary scores; simple scoring; 0–60	Total score for individuals with LBP: Mean (SD) 23.4 (8.7)
Igwesi-Chidobe et al. (2020), cross-cultural adaptation, test-retest measurements and cross-sectional study [19]	12 (cross-cultural adaptation, pilot/pretesting); 50 (Test-retest reliability); 200 (Construct validity)	Depending on subgroup: 45.0 (10.36); 45.2 (11.55); 48.6 (12.0)	Depending on subgroup: 41.7%; 64.0%; 44.0%	Chronic LBP; chronic duration not specified	Urban and rural areas of Nigeria	Nigeria; African region; lower-middle income	WHODAS-36;Igbo	Participation rate not reported	Interview-based	Summary and domain scores; complex scoring; 0–100 scale	Total score:Mean (SD) 22.8 (15.7), min 0, max 63.5; no floor or ceiling effects observed in the total score
Other
Garin et al. (2010), cohort study [22]	1190 (entire sample) 118 (LBP specific)	52.7 (15.6)	56.2%	9.9% of entire sample with LBP; duration not specified	Seven different European centers	Czech Republic, Germany, Italy, Slovenia, Spain; European region; high-income	WHODAS-36; language not specified	Response rate not reported for entire sample Stable at 6 weeks; LBP specific n = 17 Improved at 3 months; LBP specific n = 11	Self-administered or interviewer-administered	Summary and domain scores; complex scoring; 0–100 scale	See Appendix III, Supplemental Digital Content, which lists the domain-specific scores
Jonsdottir et al. (2010), cross-sectional study[17]	118	52.15 (14.50)	60.17%	Chronic LBP; mean duration 8.53 years (SD 11.03)	Orthopedic department and clinic for physical medicine	Italy and Germany; European region; high-income	WHODAS-36; Italian and German	Response rate not reported	Self-administered	Summary score; complex scoring; 0–100 scale	Total score:Mean (SD) 33.26 (17.38)

LBP, low back pain; ODI, Oswestry Disability Index; SE, standard error; WHODAS, World Health Organization Disability Assessment Schedule.

^aMode of administration includes self-report, interview-based, parent/proxy report, etc.

^bScoring method includes scale, summary or domain score, simple or complex scoring.

^cWHODAS score includes mean and SD; median and interquartile range; range (min, max); ceiling and floor effects; proportion (%) in categories.

*As per World Bank.

Pre-rehabilitation scores measured using WHODAS

WHO Disability Assessment Schedule-36 in persons with acute low back pain

In persons with acute LBP, the mean WHODAS-36 summary score (complex scoring) was 22.8/100 (SD 15.4) based on one study conducted in the region of the Americas (high-income country) [20].

WHO Disability Assessment Schedule-36 in persons with chronic low back pain

In persons with chronic LBP, the mean WHODAS-36 summary score (complex scoring) ranged from 22.8/100 (SD 15.7; range of 0 to 63.5) [19] to 41.5/100 (SD 13.8) [21] based on three studies, two conducted in the European region (high-income) [17,21] and one in the African region (lower-middle income country) [19].

WHO Disability Assessment Schedule-12 in persons with chronic low back pain

In persons with chronic LBP, the mean WHODAS-12 summary score (simple scoring) ranged from 11.4/48 (SD 8.7) [24] to 14.4/48 (SD 9.4) [23] based on two studies conducted in the European region (high-income countries). Note that the former results [24] were presented originally on a 12–60 scale, and we have transformed them to have the same scaling for both results. In persons with chronic LBP, the mean WHODAS-12 summary score (complex scoring) was 25.8/100 (SD 2.2) based on one study conducted in the region of the Americas (high-income country) [18].

WHO Disability Assessment Schedule-36 domain-specific scores in persons with low back pain (duration not specified)

The WHODAS-36 domain-specific scores (complex scoring, 0–100 scale) varied in persons with mild LBP (defined as 0–3 pain intensity on a 0–10 scale), moderate LBP (4–6 pain intensity) and severe LBP (7–10 pain intensity) based on one study conducted in the European region (high-income country) [22]. In this study, the reported mean WHODAS-36 domain scores ranged from: (1) 7.4 (SD 12.7) for ‘self-care’ to 31.5 (SD 29.6) in ‘life activities (household)’ in persons with mild LBP; (2) 13.4 (SD 16.1) for ‘self-care’ to 35.1 (SD 26.2) for ‘life activities (household)’ in persons with moderate LBP and (3) 10.5 (SD 14.5) for ‘getting along with people’ to 45.2 (SD 27.9) for ‘life activities (household)’ in persons with severe LBP.

Floor and ceiling effects of WHO Disability Assessment Schedule-36

Two studies conducted in the European (high-income country) and African (lower-middle income country) region reported no floor or ceiling effects observed in WHODAS-36 summary scores (complex scoring, 0–100) in persons with chronic LBP [19,21]. Floor and ceiling effects were defined as ≥15% of participants providing the lowest or highest possible score on the WHODAS-36, respectively [19,21].

Discussion

Our scoping review summarizes results from available studies reporting pre-rehabilitation levels of functioning measured using WHODAS in persons with nonspecific LBP excluding surgical interventions. Evidence suggests that persons with LBP seeking rehabilitation have moderate limitations in functioning, and limitations level tends to be worse in those with chronic LBP. Levels of pre-rehabilitation functioning in persons with LBP measured using WHODAS may be comparable to those with other musculoskeletal conditions or cancer, but disability levels may be lower when compared to severe cases of certain conditions including depression and rheumatoid arthritis [22,24–26]. For example, Garin et al. [22] reported that mean WHODAS-36 scores in persons with severe LBP were more than 20/100 points lower than mean WHODAS-36 scores in persons with severe depression or rheumatoid arthritis.

To our knowledge, this is the first comprehensive review of pre-rehabilitation functioning scores measured using WHODAS in persons with nonspecific LBP seeking rehabilitation. Historically, functioning for LBP has been measured in clinical settings with LBP-specific scales (e.g. Oswestry Disability Index, Roland Morris Disability Questionnaire and others), which typically focus on condition-specific limitations in functioning [5]. However, little is known about the level of functioning measured using generic instruments in this population. Our review provides evidence on the overall level of functioning in persons with nonspecific LBP measured using WHODAS, which covers the major domains of functioning as linked to the ICF [8]. Due to the limited number of studies, we were unable to assess for differences in functioning levels among persons with nonspecific LBP across different world regions or between low- and middle-income versus high-income countries. Since almost all relevant studies (7/8) were conducted in high-income countries, studies are needed to assess pre-rehabilitation functioning among persons with LBP in low- and middle-income countries.

In this scoping review, most studies (7/8) reporting pre-rehabilitation WHODAS scores in persons with LBP were conducted in clinical or rehabilitation settings [17,19–24]; only one study in this scoping review was conducted in the general population [18]. The limited number of studies precluded us from determining whether pre-rehabilitation WHODAS scores meaningfully differ between persons with LBP who present to clinical settings for rehabilitation compared to those in the general population. People with difficulties accessing health care services are more likely to have poor or fair self-rated health [27]. On the other hand, those with LBP and worse functioning are more likely to seek health care [28]. It is therefore unclear whether using pre-rehabilitation WHODAS scores collected in clinical or rehabilitation settings would underestimate or overestimate the level of limitations for LBP in the general population. Studies are needed to determine the extent to which our findings apply to persons with LBP at the population level. We conducted a systematic review that estimated a minimal detectable change of 10.45-13.99/100 and minimal important change of 9.74/100 for WHODAS-36 (complex scoring), and a minimal detectable change of 8.6/48 and minimal important change of 4.68/48 for WHODAS-12 (simple scoring) [9]. In addition to pre-rehabilitation WHODAS scores, this information provides a threshold of important benefit to inform monitoring of effective coverage for back pain rehabilitation at the population level.

This scoping review identified only eight relevant studies, which were mostly conducted in the European region and in samples with chronic LBP. Therefore, there may be limited generalizability of the pre-rehabilitation WHODAS scores identified. Nonetheless, the review findings help to inform our understanding of levels of functioning for LBP, and WHODAS can be used in both clinical and population-based settings. Future directions may assess the use of WHODAS, a questionnaire applicable across health conditions, to measure functioning related to rehabilitation interventions at the population level. For example, a previous study converted WHODAS scores that were pre- and post-intervention (rehabilitation) to calculate disability weights [29]. Disability weights can then be used to calculate population health summary measures, such as Quality-Adjusted Life Years, Disability-Adjusted Life Years and Years Lived with Disability. Future research in this area is warranted.

Strength and limitations

Our scoping review has strengths. Our review was planned a priori with the protocol registered on Open Science Framework Registries. We followed recommended approaches to the conduct and reporting of scoping reviews, including the 6-step framework outlined by Arksey and O’Malley and advanced by others[11–13] and the PRISMA Extension for Scoping Reviews Statement [10]. In addition, we conducted pilot testing of screening to calibrate reviewers, involved pairs of independent reviewers for screening using predefined eligibility criteria, and had one reviewer extract data and a second reviewer verify all extracted data.

Our review has limitations. First, we included studies published in English, French, Farsi, Chinese, German, Greek, Swedish or Italian languages to increase the feasibility of conducting this review. Evidence suggests that this language restriction likely did not greatly impact our results [30,31]. In addition, we did not identify any possibly relevant studies published in other languages during screenin g. Second, we did not conduct a search of gray literature for feasibility reasons. However, we employed a comprehensive search strategy of multiple databases that was peer-reviewed by a second librarian using the Peer Review of Electronic Search Strategies Checklist [14]. We also conducted a supplemental search of a related systematic review to identify any relevant studies.

Conclusion

Our scoping review comprehensively summarizes available data reporting on pre-rehabilitation levels of functioning measured using the WHODAS in persons with nonspecific LBP. Evidence suggests that persons with nonspecific LBP seeking rehabilitation have moderate limitations in functioning, and limitations level tends to be worse in persons with chronic LBP. Future studies assessing WHODAS functioning scores among persons with LBP in low- and middle-income countries are needed.

Acknowledgements

The authors thank Dr. Dorcas Beaton, PhD for helpful suggestions on methodology and Mr. Kent Murnaghan, MA, MIST for peer review of the search strategy. This research was funded by the Canadian Chiropractic Research Foundation (#2021-02). The funder was not involved in the design, data collection, analysis, interpretation, writing of the report, or the decision to submit the article for publication. This research was undertaken, in part, thanks to funding from the Canada Research Chairs Program to Professor Pierre Côté, Canada Research Chair in Disability Prevention and Rehabilitation at Ontario Tech University.

OSF Registries (https://osf.io/gqyvb).

Conceptualization: J.W., A.D., S.H.J., W.D.G., A.C. and P.C. Methodology: J.W., A.D., S.H.J., W.D.G., S.M., P.S., D.S., S.A., M.B., N.L., M.N. and P.C. Literature search: K.M. Data collection: J.W., A.D., H.V., S.M., P.S., D.S., S.A., M.B., N.L. and P.C. Writing – original draft: J.W., with input from A.D., P.C. Writing – review and editing: J.W., A.D., S.H.J., W.D.G., H.V., S.M., P.S., D.S., S.A., M.B., N.L., M.N., K.M., A.C. and PC. All authors read and approved the final article.

Conflicts of interest

J.J.W. reports research grants from the Canadian Chiropractic Research Foundation (paid to institution); and the Canadian Institutes of Health Research (CIHR; paid to institution) outside the submitted work. P.C. reports research grants from the Canadian Chiropractic Research Foundation (paid to institution); CIHR, College of Chiropractors of British Columbia, and the WHO (paid to institution) outside the submitted work; payment for expert (court) testimony from the Canadian Chiropractic Protective Association and NCMIC; and support for attending meetings and/or travel from Eurospine, Sophiahemmet University, and World Federation of Chiropractic. M.C.N. reports leadership role (unpaid) with World Spine Care, SPINE20, and Eurospine. For the remaining authors, there are no conflicts of interest.