The Work Limitations Questionnaire's validity and reliability among patients with osteoarthritis.

The 25-item Work Limitations Questionnaire (WLQ) was recently developed to measure health-related decrements in ability to perform job roles among employed individuals. Research has demonstrated its validity and reliability in several populations. We assessed the WLQ's performance when administered to patients with osteoarthritis (OA), which is a leading cause of work disability and productivity loss. We recruited a representative sample of 230 employed, confirmed OA patients and a comparison group of 37 healthy employed controls. Subjects completed a mail survey. In tests of the WLQ's scale internal reliability, the questionnaire met all established criteria. Additionally, in construct validity tests, the WLQ correctly detected OA vs. control group differences, and correlated significantly with arthritis pain, stiffness, and functional limitation, and self-reported work productivity. The WLQ is an accurate and reliable source of information for assessing the work impact of OA.