Abstract
OBJECTIVE: To systematically rate the evidence on the measurement properties of work functioning instruments for people with arthritis and other rheumatologic conditions. METHODS: A systematic review was conducted through a structured search to identify the quality of articles describing studies of assessment development and studies of their psychometric properties. The Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist was used to appraise the included studies. Finally, an evidence synthesis was performed to combine findings. RESULTS: Nine arthritis-specific work outcome assessments were identified; 17 articles examining the psychometric properties of these instruments were identified and their quality was reviewed. Quality of studies was highly variable. The evidence synthesis showed that the Work Limitations Questionnaire had the strongest quality evidence of internal consistency and content validity (including structural validity and hypothesis testing), followed by the Work Instability Scale. None of the instruments had strong quality evidence of criterion validity or responsiveness. CONCLUSION: Considering the high variability and the low quality of the literature, we recommend that instrument developers integrate a full psychometric assessment of their instruments, including responsiveness and criterion validity, and consult guidelines (i.e., COSMIN) in reporting their findings.