OBJECTIVES: Examine the relationship of statin noncompliance to subsequent hospitalization among new statin users after coronary heart disease (CHD) hospitalization. METHODS: Medstat Marketscan 1999-2002 databases including inpatient, outpatient and pharmacy claims were utilized for this study. The first statin prescription fill date within six months of CHD hospitalization was identified as the index date. The sample consisted of adults who had no statin use during the year prior to the CHD hospitalization and had at least 2-years continuous enrollment after the index date. Medication possession ratio (MPR) was calculated as the ratio of total days supply of statins to the total days during the first year after the index date (initial use period). Statin noncompliance was defined as having a MPR less than 80%. The outcome was hospitalization during the year following the initial use period. Association of statin noncompliance in the initial use period to subsequent hospitalization was examined by multiple logistic regression, controlling for age, gender, region, comorbidity, prior hospital admission and number of drug therapeutic classes in the initial use period. RESULTS: A total of 3063 subjects met the inclusion criteria and were included in the analysis. A total of 1170 (38.2%) had a MPR less than 80% in the initial use period. Compared with patients who were compliant to statins, noncompliant patients were about 40% more likely to have a subsequent hospitalization (OR: 1.37; 95% CI, 1.13-1.65). Other factors associated with significantly higher risk of subsequent hospitalization included female gender, older age, higher Charlson comorbidity index score, higher number of drug therapeutic classes, and prior hospitalization in the use period. CONCLUSIONS: Statin noncompliance in the year after CHD hospitalization was common among new statin users and associated with higher risk of subsequent hospitalization. These findings suggest that interventions to improve compliance could reduce risk for hospitalization.