Influence of baseline low-density lipoprotein cholesterol values on statin therapy persistence

Abstract

Purpose: Persistence to statins is low, in part due to lack of perception of cardiovascular (CV) risk. High values of low-density lipoprotein cholesterol (LDL-C) might increase the motivation for patients to be persistent. We investigated whether the baseline LDL-C value influences the discontinuation of statin treatment in patients with and without previous CV events.

Methods: A cohort study was performed using information from the Swedish national registers concerning dispensed drugs, hospital contacts, cause of death, and socioeconomic status, and linked with data from clinical laboratories. Incident statin users 20 years of age or older and starting treatment between 2006 and 2007 were identified and followed for 1 year. Baseline LDL-C level was defined as the last available laboratory test result during 6 months before the index statin dispensing. Cox regression was used to study discontinuation and estimate the effect on persistence of the baseline LDL-C value adjusting for sex, age, income, comorbidity, previous CV events, type of prescriber, and country of birth. Subgroup analyses stratifying by previous CV events and by diagnosis of diabetes among subjects without previous CV events were performed.

Results: A total of 29,389 patients were identified; 35.4% had a previous CV event. A high baseline LDL-C value was associated with a lower discontinuation rate (hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.72-0.91) in patients without previous CV events. When stratifying further by diabetes diagnosis, the association was confirmed only in patients without diabetes. No association between LDL-C and persistence was found in patients with previous CV events.

Conclusions: High levels of LDL-C were positively associated with statin persistence in newly treated diabetes patients without previous CV events.

Keywords: Lipid values; Persistence; Pharmacoepidemiology; Statin; Therapy discontinuation.