PCV9 Association Between Persistence With Statins and Reduction of Low Density Lipoprotein Cholesterol: Analysis of Real-Life Data from Community Settings

Abstract

To quantify the association between persistence with statins and low density lipoprotein cholesterol (LDL-C) levels using "real-life" data in community settings. A retrospective population-based cohort study was conducted among eligible 87,219 primary-prevention and 15,139 secondary-prevention patients who are members of a large health maintenance organization and initiated statins therapy between 1998 and 2008. Baseline and follow-up LDL levels were collected from three months prior to the date of first dispensed statins (index date) to six months afterwards. Persistence was assessed by proportion of follow-up days covered (PDC) with statins. Over the study follow-up period, there were significant (P< 0.001) reductions in LDL-C levels of 54, 33 and 13 mg/dl among highly persistent (PDC>=80%), poorly persistent (34%<=PDC<80%), and non-persistent statins users (PDC<=33%), respectively. In a multivariable model, high persistence with statins therapy was associated with a 27% and 25% decrement in LDL-C level among primary and secondary prevention cohorts, respectively. Similarly, a higher proportion of the persistent statins users reached target LDL-C level within the study follow-up period (80% and 58% among primary and secondary prevention cohorts, compared to only 28% and 17%, among non-persistent patients). In this observational population-based study, calculated PDC with statins during study follow-up was strongly associated with drug effect of LDL-C reduction. The results agree with previous estimates of statins efficacy from randomized clinical trials, supporting the validity of using PDC methods as a measure of drug exposure.