Can We Identify Minority Patients at Risk of Nonadherence to Antiplatelet Medication at the Time of Coronary Stent Placement?

BACKGROUND: Lack of medication adherence is associated with significant morbidity and mortality, particularly among minorities. We aim to identify predictors of nonadherence to antiplatelet medications at the time of percutaneous coronary intervention (PCI) with stent among African American and Hispanic patients. METHODS: We used data collected for a randomized clinical trial that recruited 452 minority patients from a large US health insurance organization in 2010 post-PCI to compare telephone-based motivational interviewing by trained nurses with an educational video. The primary outcome was 12-month adherence to antiplatelet medications measured by the claims-based medication possession ratio (MPR). Adequate adherence was defined as an MPR of 0.80 or higher. RESULTS: More than half of the sample (age, 69.52 ± 8.8 years) was male (57%) and Hispanic (57%). Most (78%) had a median income below $30 000 and 22% completed high school or higher. Univariate analyses revealed that symptoms of depression (<.01) and not having a spouse (P = .03) were associated with inadequate adherence. In multivariate analysis, baseline self-reported adherence (1.4; 95% confidence interval [CI], 1.05-1.89), depressive symptoms (0.49; 95% CI, 0.7-0.90), comorbidity (0.89; 95% CI, 0.80-0.98), and telephone-based motivational interviewing by trained nurses (3.5; 95% CI, 1.9-2.70) were associated with adherence. CONCLUSIONS: Having multiple comorbidities, depression, suboptimal adherence to medications, and low English proficiency at the time of PCI increase the risk of poor 12-month adherence to antiplatelets among minorities. Identifying these risk factors can guide PCI therapy and the use of evidence-based strategies to improve long-term adherence.