Associations between Health Assessment Questionnaire Disability Index and physical performance in rheumatoid arthritis and osteoarthritis.

Objectives: To investigate whether the Health Assessment Questionnaire Disability Index (HAQ-DI) reflects objective measures of physical function in people with osteoarthritis (OA) and rheumatoid arthritis (RA).

Methods: In total, 139 people, 71 with RA fulfilling the American College of Rheumatology (ACR) criteria (1987) and 68 with OA fulfilling ACR criteria for OA of the hip or knee, completed the HAQ-DI. Physical function was assessed using Timed Up and Go (TUG), 30 seconds Sit to Stand (STS), grip strength dynamometry and pedometer steps over 7 days.