Statin Discontinuation, Reinitiation, and Persistence Patterns Among Medicare Beneficiaries After Myocardial Infarction: A Cohort Study.

BACKGROUND Although the benefits of statins accrue over time, treatment discontinuation is common. Examining the patterns of statin discontinuation, reinitiation, and persistence after reinitiation among Medicare beneficiaries after hospital discharge for a myocardial infarction may help increase statin use in high-risk patients. METHODS AND RESULTS Medicare beneficiaries with a statin fill claim within 30 days after hospital discharge for myocardial infarction in 2007 to 2012 (n=158 795) were followed for 182 days post-discharge to identify discontinuation, defined as 60 continuous days without statins available. Reinitiation, defined by a statin fill, was identified in the 365 days post-discontinuation. High persistence was defined as proportion of days covered ≥80% with ≥1 day of statin supply 182 days after reinitiation. Follow-up ended on December 31, 2014. In the 182 days after myocardial infarction hospital discharge, 15.4% of beneficiaries discontinued statins. Of this group, 53.7% reinitiated statins. On reinitiation, 27.1% changed statin type, 6.9% up-titrated intensity, 14.4% down-titrated intensity, and 66.0% had the same statin and intensity. In the 182 days after reinitiation, 45.8% had high persistence. Moderate- and high- versus low-intensity statins were associated with a lower risk for statin discontinuation (moderate intensity: relative risk [RR], 0.93; 95% confidence interval [CI], 0.89-0.96; high-intensity: RR, 0.95; 95% CI, 0.91-0.99). High persistence was less common after reinitiating high- versus low-intensity statins (RR, 0.80; 95% CI, 0.75-0.86), but no association was present for those reinitiating a moderate- versus low-intensity statin (RR, 0.95; 95% CI, 0.90-1.01). Down-titrating versus reinitiating the same statin intensity (RR, 1.10; 95% CI, 1.05-1.16) and reinitiating a different versus the same statin (RR, 1.10; 95% CI, 1.06-1.14) were associated with high persistence after treatment reinitiation. CONCLUSIONS Although many people who discontinue a statin reinitiate treatment, statin persistence after reinitiation was low. Reinitiating therapy with moderate-intensity statins, down-titration, and using a different statin may promote persistence.