Statin use and risk of joint replacement due to osteoarthritis and rheumatoid arthritis: a propensity-score matched longitudinal cohort study.

OBJECTIVE: Statins are reported to have a potential benefit on progression of OA and on disease activity in RA, but existing evidence is conflicting. Our objective was to examine whether statins associate with reduction in the risk for joint replacement due to OA and RA. METHODS: This was a propensity score-matched cohort study. Electronic health records from the UK Clinical Practice Research Datalink were used. We selected people prescribed statins and people never prescribed statins. Each statin user was matched to a non-user by age, gender, practice and propensity score for statin prescription. The main outcome measures were knee or hip joint replacement overall, and specifically because of OA or RA. The association between statins and risk of joint replacement was assessed using Cox proportional hazard regression. Statin exposure was categorized according to the potency of reducing low-density lipoprotein as low (21-28%), medium (32-38%) or high (42-55%) intensity. RESULTS: A total of 178 467 statin users were matched with 178 467 non-users by age, gender, practice and propensity score. Overall, statin was not associated with reduced risk of knee or hip replacement (hazard ratio 0.99, 95% CI: 0.97, 1.03), unless prescribed at high strength (0.86, 0.75-0.98). The reduced risk was only observed for joint replacement due to RA (0.77, 0.63-0.94) but not OA (0.97, 0.94-1.01). CONCLUSION: Statins at high intensity may reduce the risk of hip or knee replacement. This effect may be RA specific. Further studies to investigate mechanisms of risk reduction and the impact in people with RA are warranted.