Instruments used to assess functional limitations in workers applying for disability benefit: a systematic review.

PURPOSE To systematically review the quality of the psychometric properties of instruments for assessing functional limitations in workers applying for disability benefit. METHOD Electronic searches of Medline, Embase, CINAHL and PsycINFO were performed to identify studies focusing on the psychometric properties of instruments used to assess functional limitations in workers' compensation claimants. Two independent reviewers applied the inclusion criteria to select relevant articles and then evaluated the psychometric qualities of the instruments found. RESULTS Of the 712 articles that were identified, 10 studies met the inclusion criteria, reporting on four instruments: the Roland-Morris Disability Questionnaire (RMDQ), the Patient-Specific Functional Scale (PSFS), the Isernhagen Work System (IWS) and the Multiperspective Multidimensional Pain Assessment Protocol (MMPAP). The questionnaires (RMDQ and PSFS) did not focus specifically on the work situation and measured three to eight functional limitations. The psychometric qualities of the IWS were poor to moderate. For the MMPAP, only predictive validity was measured. The instruments assessed a range varying between 3 and 34 physical functional limitations. No instruments were found for assessing mental limitations in workers' compensation claimants. CONCLUSION Studies on four instruments specifically focusing on assessing physical functional limitations in workers applying for disability benefit were found. All four instruments have limitations regarding their psychometric qualities or contents. Since the RMDQ has the best demonstrated psychometric qualities and takes little time to complete it, we recommend the RMDQ for clinicians in rehabilitation. For the assessment of functional limitations in workers applying for disability benefit a combination of questionnaires, performance tests or interviews together with the judgment by physicians looks the most promising.