Measurement Properties and Minimal Important Change of the World Health Organization Disability Assessment Schedule 2.0 in Persons With Low Back Pain: A Systematic Review.

OBJECTIVE: To determine the measurement properties and minimal important change (MIC) of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) short (12 questions) and full (36 questions) versions in persons with nonspecific low back pain (LBP). DATA SOURCES: MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, APA PsycInfo, and Cochrane Central Register of Controlled Trials (inception to May 2021). STUDY SELECTION: Eligible studies assessed measurement properties or MIC of WHODAS 2.0 in persons with LBP. DATA EXTRACTION: Paired reviewers screened articles, extracted data, and assessed risk of bias using Consensus-Based Standards for Selection of Health Measurement Instruments (COSMIN) and COSMIN-Outcome Measures in Rheumatology checklists. DATA SYNTHESIS: We descriptively synthesized results stratified by measurement property and LBP duration (subacute: 6 weeks to 3 months; chronic: ≥3 months). RESULTS: We screened 297 citations and included 14 studies (reported in 15 articles). Methodological quality of studies was very good for internal consistency and varied between very good and doubtful for construct validity, doubtful for responsiveness, and adequate for all other properties assessed. Evidence suggests that WHODAS 2.0 full version has adequate content validity (2 studies); WHODAS 2.0 short and full versions have adequate structural validity (3 studies), but construct validity is indeterminate (9 studies). WHODAS 2.0 short and full versions have adequate internal consistency (10 studies), and the full version has adequate test-retest and interrater reliability (3 studies) in persons with LBP. Minimal detectable change (MDC) was 10.45-13.99 of 100 for the full version and 8.6 of 48 for the short version in persons with LBP (4 studies). WHODAS 2.0 full version has no floor or ceiling effects, but the short version has potential floor effects in persons with chronic LBP (3 studies). One study estimated MIC for the full version as 4.87 of 100 or 9.74 of 100 (corresponding to 1- and 2-point change on 0- to 10-cm visual analog scale for pain, respectively), and 1 study estimated 3.09-4.68 of 48 for the short version. CONCLUSIONS: In persons with LBP, WHODAS 2.0 full version has adequate content validity, structural validity, internal consistency, and reliability. WHODAS 2.0 short version has adequate structural validity and internal consistency. Construct validity of the short and full versions is indeterminate. Since MDC is estimated to be larger than MIC, users may consider both MIC and MDC thresholds to measure change in functioning for LBP.

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

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.