Objective: To assess associations between joint-specific hand symptoms and self-reported and performance-based functional status.
Methods: Participants were from the population-based Johnston County Osteoarthritis Project. Symptoms in the distal interphalangeal (DIP), proximal interphalangeal (PIP), first carpometacarpal (CMC), and metacarpophalangeal (MCP) joints were assessed on a 30-joint diagram of both hands. Self-reported function was assessed by Health Assessment Questionnaire (HAQ) and performance-based function by timed repeated chair stands and 8 foot walk time. Separate multiple logistic regression models examined associations between symptoms in specific hand joint groups, symptoms in ≥ 2 hand joint groups, and number of symptomatic hand joints, and functional status measures, controlling for age, race/ethnicity, sex, body mass index, radiographic knee and hip OA, knee and hip symptoms, and depressive symptoms.
Results: Those with symptomatic hand joint groups were more likely than those without these complaints to report more difficulty and require longer times for performance measures. Those with 2 or more symptomatic hand joint groups were more likely to have higher HAQ scores (OR = 1.97 [1.53 - 2.53]) and require more time to complete 5 chair stands (OR=1.98 [1.23 - 3.18]) and the 8 foot walk test (OR=1.49 [1.12 - 1.99]).
Conclusions: Joint-specific hand symptoms are associated with difficulty performing upper or lower extremity tasks, independent of knee and hip OA and symptoms, suggesting that studies examining functional status in OA should not ignore symptomatic joints beyond the joint site of interest, even when functional measures appear to be specific for the joint site under study.