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

OBJECTIVE: The study investigated 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 the ages of 65-85 in a prospective, observational population-based study with 12-18 month 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 Minimal Clinically Important Difference of 4 on the AUStralian/CANadian hand OA Index and of 2 on the Western Ontario and McMaster Universities hip/knee OA 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/anti-inflammatory 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/anti-inflammatory medications mediated the combined effect of hip/knee OA+pain on functional decline in the 554 individuals classified as having "worse" hip/knee functionality and the 1,291 "not worse" persons. Peripheral artery disease, obesity, and cognitive impairment were other baseline risk factors.

CONCLUSION: Study findings showed that together with emotional status, chronic physical and cognitive conditions, OA affects hand and hip/knee functional decline.