Impact of Patient and Plan Design Factors on Switching to Preferred Statin Therapy

Background:Changing formulary status is a common strategy to encourage greater use of lower-cost brand and generic drugs.Objective:To examine the relationship between patient and plan design factors and formulary adherence after the formulary status change of atorvastatin.Methods:We conducted a cross-sectional, cohort study of patients enrolled in one of 2139 commercial (no Medicare or Medicaid) plans that offer a 3-tier benefit design and changed atorvastatin from formulary to nonformulary status on January 1,2006. Adults on atorvastatin therapy who were receiving targeted communications in the fourth quarter of 2005 were included for analysis. We used bivariate and multivariate logistic regression analyses to examine the relationship between covariates and formulary adherence for patients receiving atorvastatin through retail or home delivery (HD) pharmacies.Results:A total of 211,083 patients met the study inclusion criteria, and more than 42% switched from atorvastatin to a formulary statin (33.1% ret...