Factors Associated With Functional Decline in Hand and Hip/Knee Osteoarthritis After One Year: Data From a Population-Based Study

Objective To investigate factors that together with hand or hip/knee osteoarthritis (OA) could contribute to functional decline over a year's time in elderly individuals. Methods The data of 1,886 individuals between ages 65 and 85 years in a prospective, observational population-based study with 12-18 months of follow-up in the context of the European Project on Osteoarthritis were analyzed. The outcome measures were self-reported hand and hip/knee functional decline, evaluated using a minimum clinically important difference of 4 on the Australian/Canadian Hand OA Index and of 2 on the Western Ontario and McMaster Universities Osteoarthritis Index hip/knee physical function subscales, both normalized to 0-100. Using regression models adjusted for sex, age, country, and education level, the baseline factors considered were clinical hand or hip/knee OA, pain, analgesic/antiinflammatory medications, comorbidities, social isolation, income, walking time, grip strength, physical activity time, and medical/social care. Results After a year, 453 participants were identified as having worse hand functionality and 1,389 as not worse. Hand OA, anxiety, walking time, and grip strength were risk factors for hand functional decline; pain was a confounder of the effect of hand OA. Analgesic/antiinflammatory medications mediated the combined effect of hip/knee OA plus pain on functional decline in the 554 individuals classified as having worse hip/knee functionality and the 1,291 persons who were not worse. Peripheral artery disease, obesity, and cognitive impairment were other baseline risk factors. Conclusion Study findings showed that together with emotional status and chronic physical and cognitive conditions, OA affects hand and hip/knee functional decline.