Initiation of statins after hospitalization for coronary heart disease

Abstract

Background: Coronary heart disease (CHD) is a major public health problem in the United States. It has been well recognized that patients with prior CHD are at very high risk for recurrent CHD. Statins have been recommended as an effective treatment in the secondary prevention of CHD.

Objective: To (1) determine the proportion of patients who received outpatient statin therapy after CHD hospitalization and (2) identify factors associated with initiation of outpatient statin use.

Methods: Using MedStat MarketScan 1999-2003 databases, CHD hospitalizations (ICD-9-CM codes 410.xx-414.xx, 429.2) between January 1, 2000, and June 30, 2003, were identified, with each patient's first such hospitalization defined as the index hospitalization. The study sample consisted of patients who had had no statin use during the year preceding the index hospitalization and had at least 6 months of follow-up after discharge. Initiation of any statin prescription during follow-up was the outcome of interest. Demographic and clinical predictors were selected with the guidance of Andersen's health services utilization model and past studies. Effects of these independent variables on statin initiation were examined using logistic regression models.

Results: Of 17,631 subjects who met the inclusion criteria, only 8,424 (7.8%) had received statin therapy within 6 months after discharge. The following characteristics were inversely related to the likelihood of receiving an outpatient statin: baseline Charlson comorbidity score (6+ vs. 1-2, odds ratio [OR] 0.35; 95% confidence interval [CI], 0.25-0.51), nonacute myocardial infarction CHD hospitalization (OR 0.55; 95% CI, 0.51-0.58), baseline psychoses (OR 0.61; 95% CI, 0.50-0.75), use of lipid-modifying drugs other than statins at baseline (OR 0.61; 95% CI, 0.53-0.71), and patient age (continuous) (OR 0.97; 95% CI, 0.97-0.98). The following characteristics were associated with a higher likelihood of receiving an outpatient statin prescription: hospitalization for CHD in a recent year (2003 vs. 2000, OR 1.77; 95% CI, 1.61-1.94), baseline dyslipidemia (OR 1.54; 95% CI, 1.41-1.68), care by a cardiologist (OR 1.26; 95% CI, 1.18-1.34), and male gender (OR 1.18; 95% CI, 1.10-1.26). In a separate analysis of subjects with complete copayment information (N=13,765), amount of copayment for the first outpatient statin prescription was inversely related to the likelihood of receiving an outpatient statin (>or=$20 vs. <$10; OR 0.62; 95% CI, 0.56-0.68). In that equation, hospitalization for CHD in 2003 instead of in 2000 multiplied the odds of receiving statin therapy after discharge by 3.31 (95% CI, 2.95-3.71).

Conclusion: Less than 50% of patients with a CHD hospitalization during the 4-year study period from 2000 through 2003 received outpatient statin therapy within 6 months after discharge, but the proportion increased each year to 56% of patients with a CHD hospitalization in 2003. For CHD patients admitted in 2003, the odds of receiving statin therapy after discharge were approximately 80% to 230% higher than for patients admitted in 2000. Higher statin copayment amount and female gender were associated with lower likelihood of receiving a statin prescription after a CHD hospitalization.