Physical functioning is a core outcome domain to be measured in nonspecific low back pain (NSLBP). A panel of experts recommended the Roland-Morris Disability Questionnaire (RMDQ) and Oswestry Disability Index (ODI) to measure this domain. The original 24-item RMDQ and ODI 2.1a are recommended by their developers.Purpose
The purpose of this study was to evaluate whether the 24-item RMDQ or the ODI 2.1a has better measurement properties than the other to measure physical functioning in adult patients with NSLBP.Data Sources
Bibliographic databases (MEDLINE, Embase, CINAHL, SportDiscus, PsycINFO, and Google Scholar), references of existing reviews, and citation tracking were the data sources.Study Selection
Two reviewers selected studies performing a head-to-head comparison of measurement properties (reliability, validity, and responsiveness) of the 2 questionnaires. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist was used to assess the methodological quality of these studies.Data Extraction
The studies' characteristics and results were extracted by 2 reviewers. A meta-analysis was conducted when there was sufficient clinical and methodological homogeneity among studies.Data Synthesis
Nine articles were included, for a total of 11 studies assessing 5 measurement properties. All studies were classified as having poor or fair methodological quality. The ODI displayed better test-retest reliability and smaller measurement error, whereas the RMDQ presented better construct validity as a measure of physical functioning. There was conflicting evidence for both instruments regarding responsiveness and inconclusive evidence for internal consistency.Limitations
The results of this review are not generalizable to all available versions of these questionnaires or to patients with specific causes for their LBP.Conclusions
Based on existing head-to-head comparison studies, there are no strong reasons to prefer 1 of these 2 instruments to measure physical functioning in patients with NSLBP, but studies of higher quality are needed to confirm this conclusion. Foremost, content, structural, and cross-cultural validity of these questionnaires in patients with NSLBP should be assessed and compared.