Determinants of the Differences in Ldl-Cholesterol After Initiation of Statin Treatment:

Background:Randomized clinical trials may not accurately predict drug benefit in clinical practice because the patients and conditions of therapy almost always differ between those settings.Objective:To determine whether differences in low-density lipoprotein cholesterol (LDL-C) time curves between clinical trial results and usual care experience after initiation of statin therapy could be explained fully in terms of observable characteristics of patients and practice in usual care.Methods:We compared LDL-C measurements for 3 years after initiation of statin treatment in individuals enrolled in a health maintenance organization (HMO), with enrollees in the active treatment arm of the CARE (Cholesterol and Recurrent Events) trial. Analysis of the determinants of variation in LDL-C in the HMO cohort was used to adjust the crude results to the distribution of patient and treatment characteristics in the trial.Results:The mean percent decrease in LDL-C was lower in the HMO cohort (n = 1245) than in the clinic...