Clopidogrel prescription filling delays and cardiovascular outcomes in a pharmacy system integrating inpatient and outpatient care: Insights from the Veterans Affairs CART Program

Background Delays in filling clopidogrel prescriptions after percutaneous coronary intervention (PCI) have been demonstrated previously and associated with adverse outcomes. Methods This was a retrospective cohort study of 11,418 patients undergoing PCI with stent placement in Veterans Affairs (VA) hospitals between January 1, 2005, and September 30, 2010. Data were obtained from the national VA Clinical Assessment, Reporting, and Tracking Program, including post-PCI clopidogrel prescription fill date and outcomes of myocardial infarction and death within 90 days of discharge. Patients who did not fill a clopidogrel prescription on the day of discharge were considered to have a delay. Multivariable models assessed the association between clopidogrel delay and myocardial infarction/death using clopidogrel delay as a time-varying covariate. Results Of the patients, 7.2% had a delay in filling their clopidogrel prescription. Delay in filling clopidogrel was associated with increased risk of major adverse events (hazard ratio 2.34, 95% CI 1.66-3.29, P < .001). The percentage of patients who delayed filling varied by hospital, ranging from 0 to 43.5% with a median of 6.2% ( P < .001, χ2 for difference across hospitals) and a median odds ratio of 2.13 (95% CI 1.85-2.68) suggesting large site variation in clopidogrel delay across hospitals. Conclusions In a health care system with integrated inpatient and outpatient pharmacy services, 1 in 14 patients delays filling a clopidogrel prescription. The large site variation suggests a need to identify best practices that allow hospitals to optimize prescription filling at discharge to potentially improve patient outcomes.