Nonadherence to statin therapy: discontinuation after a single fill

Adherence to statin medications is known to be suboptimal. What is less known is the rate of discontinuation immediately after therapy has been initiated. The primary objective of this study was to determine what proportion of nonadherence in the first year of statin therapy was due to discontinuation after a single fill.

We identified new statin users within low-risk (hypertension [HTN]), medium-risk (coronary heart disease [CHD]), and high-risk (heart failure [HF]) cohorts during a 9-year period. All data came from administrative health care databases.

The cohorts included 9445 HTN, 1141 CHD, and 778 HF patients. At 1 year, the proportions of patients with less than 80% adherence to statin medications were 47.9% (HTN), 38.3% (CHD), and 50.0% (HF). Among all patients classified as nonadherent at 1 year, 18.0% of HTN, 16.3% of CHD, and 28.2% of HF patients had discontinued statin medications after only 1 dispensation. Within 3 months of starting statin therapy, 29.7%, 40.3%, and 47.5% of all nonadherent HTN, CHD, and HF patients, respectively, had discontinued the new statin medication. After regression analysis, the only independent covariate that was consistently associated with discontinuation after a single fill was receiving fewer medical follow-up visits.

Immediate discontinuation after a single fill contributes disproportionately to statin nonadherence. This suggests an important time to prevent nonadherence is within the first month of treatment initiation.