Physical Performance and Central Nervous System-Active Analgesics Independently Predict 8-Year Fall Risk in Adults with or at Risk for Knee Osteoarthritis.

OBJECTIVE

To determine whether baseline objective physical performance and central nervous system (CNS)-active analgesics use independently and jointly predict long-term fall risk among adults with or at risk for knee osteoarthritis (OA).

DESIGN

Prospective longitudinal cohort study.

SETTING

Community-based cohort from the Osteoarthritis Initiative.

PARTICIPANTS

A total of 4,783 adults aged 45-79 years with or at risk for knee OA.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Baseline exposure included CNS-active analgesic use (opioids or antidepressants). Physical performance was assessed using the repeated chair-stand test and 400-m walk test. The primary outcomes were the incidence of any falls (≥1) and recurrent falls (≥2) over 8 years. Associations were estimated using generalized estimating equations adjusted for demographic characteristics, body mass index, and depressive symptoms.

RESULTS

CNS-active analgesics use at baseline was associated with higher odds of any fall (adjusted odds ratio [AOR]: 1.16; 95% confidence interval [CI]: 1.08-1.24) and recurrent falls (AOR: 1.30; 95% CI: 1.18-1.42). Poorer physical performance was also associated with increased fall risk. Slower 400-m walk times and inability to complete the chair-stand test were independently associated with both outcomes. No statistically significant interaction was observed between analgesic use and physical performance measures.

CONCLUSIONS

Among adults with or at risk for knee OA, CNS-active analgesic use and impaired physical performance were independent predictors of long-term fall risk. Routine assessments of physical performance help clinicians identify individuals at greater risk of falls when prescribing CNS-active medications and guide the development of tailored fall-prevention strategies in rehabilitation.