Analgesic use and risk of recurrent falls in participants with or at risk of knee osteoarthritis: data from the Osteoarthritis Initiative

Abstract

Objective: Few studies have compared the risk of recurrent falls across different types of analgesic use, and with limited adjustment for potential confounders (e.g., pain/depression severity). We assessed analgesic use and the subsequent risk of recurrent falls, among participants with or at risk of knee osteoarthritis (OA). Methods: A longitudinal analysis included 4231 participants aged 45-79 years at baseline with 4-year follow-up from the Osteoarthritis Initiative (OAI) cohort study. We grouped participants into six mutually exclusive subgroups based on annually assessed analgesic use in the following hierarchical order of analgesic/central nervous system (CNS) potency: use of (1) opioids, (2) antidepressants, (3) other prescription pain medications, (4) over-the-counter (OTC) pain medications, (5) nutraceuticals, and (6) no analgesics. We used multivariable modified Poisson regression models with a robust error variance to estimate the effect of analgesic use on the risk of recurrent falls (>= 2) in the following year, adjusted for demographics and health status/behavior factors. Results: Opioid use increased from 2.7% at baseline to 3.6% at the 36-month visit (>80% using other analgesics/nutraceuticals), while other prescription pain medication use decreased from 16.7% to 11.9% over this time period. Approximately 15% of participants reported recurrent falls. Compared to those not using analgesics, participants who used opioids and/or antidepressants had a 22-25% increased risk of recurrent falls (opioids: RRadjusted = 1.22, 95% CI = 1.04-1.45; antidepressants: RRadjusted = 1.25, 95% CI = 1.10-1.41). Conclusion: Participants with or at risk of knee OA who used opioids and antidepressants with/without other analgesics/nutraceuticals may have an increased risk of recurrent falls after adjusting for potential confounders. Use of opioids and antidepressants warrants caution. Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International.