Statin persistence and adherence among older initiators: A nationwide cohort study using the national health insurance claims database in Japan.

PURPOSE

This study clarifies the reality of persistence and adherence to statins in older Japanese people who initiated statin use and compares it between primary and secondary prevention cohorts.

METHODS

The nationwide study using the national claims database targeted statin initiators aged ≥55 years from FY2014 to FY2017 in Japan. Persistence and adherence to statins were analyzed overall and according to subgroups based on sex, age stratum, and prevention cohorts. Permissible gap of median days that statins were supplied per prescription to an individual was employed. Persistence rates were estimated as Kaplan-Meier estimates. Poor adherence during persistence was evaluated and defined as <0.8 of the proportion of days covered.

RESULTS

Of 3 675 949 initiators, approximately 80% initiated statin use with strong variants. The persistence rate at 1 year was 0.61. Poor adherence to statins during persistence was 8.0% in all patients and this value gradually improved with increasing age. Persistence rate and adherence were lower for the primary prevention cohort than for the secondary prevention cohort, and a notable sex difference was observed for the secondary prevention cohort, which was lower in females but was almost never and slightly observed in the primary prevention cohorts without and with high-risk factors, respectively.

CONCLUSIONS

Many statin initiators discontinued statins shortly following statin initiation but adherence while on statin therapy was good. Attentively watching older patients not to discontinue statins and listening to their reasons for discontinuation are required, especially for initiators in primary prevention and females in secondary prevention.