Association of Statin Therapy With Risk of Epilepsy in 2 Propensity Score-Matched Cohorts

Background: Studies have suggested that statins may have a neuroprotective effect against epilepsy. However, evidence from rat models and case reports have suggested an opposite effect. Overall data are limited. Objective: To examine the association between statin use and epilepsy risk in a general population and in a healthy population (individuals with no severe comorbidities). Methods: Patients were Tricare beneficiaries from October 2003 to March 2012. Based on patients' characteristics during baseline phase (fiscal year [FY] 2004-2005), 2 propensity score (PS)-matched cohorts of statin users and nonusers were formed: (1) a PS-matched general cohort and (2) a PS-matched healthy cohort. Our outcome was defined using inpatient or outpatient ICD-9 codes for epilepsy during the follow-up phase (FY 2006 to March 2012) in the cohorts of statin users and nonusers. Results: The study included a total of 43 438 patients (13 626 statin users and 29 812 nonusers). The PS-matched general cohort matched 6342 statin users to 6342 nonusers; the odds ratio (OR) of epilepsy in this cohort during follow-up was 0.91; 95% CI = 0.67-1.23. The PS-matched healthy cohort matched 3351 statin users to 3351 nonusers; OR in the PS-matched healthy cohort during follow-up was 1.08; 95% CI = 0.64-1.83. Conclusions: This study did not demonstrate a significant beneficial or deleterious effect of statin use on risk of being diagnosed with epilepsy. Clinicians should not withhold statins, whenever indicated, in patients with epilepsy.