BACKGROUND:

Medicare Part D improved access to cardiovascular medications. Increased cardiovascular drug use and resulting health improvements could be derailed when beneficiaries enter the coverage gap and must pay 100% of drug costs. The coverage gap remains the subject of Congressional debate; evidence regarding its impact on cardiovascular drug use and health outcomes is needed.

METHODS AND RESULTS:

We followed 122 255 Medicare beneficiaries with cardiovascular conditions with linked prescription and medical claims who reached the coverage gap spending threshold in 2006 or 2007. Beneficiaries entered the study on reaching the threshold and were followed until an event, the catastrophic coverage spending threshold, or year's end. We matched 3980 beneficiaries who reached the threshold and received no financial assistance (exposed) to 3980 with financial assistance during the gap period (unexposed), using propensity score and high-dimensional propensity score approaches. We compared rates of cardiovascular drug discontinuation, drug switching, and death or hospitalization for acute coronary syndrome (ACS) plus revascularization, congestive heart failure, or atrial fibrillation. In propensity score-matched analyses, exposed beneficiaries were more likely to discontinue (hazard ratio, 1.57; 95% confidence interval, 1.39 to 1.79; risk difference,13.76; 95% confidence interval, 10.99 to 16.54 drugs/100 person-years) but no more or less likely to switch cardiovascular drugs. There were no significant differences in rates of death (propensity score-matched hazard ratio,1.23; 95% confidence interval, 0.89 to 1.71) or other outcomes.

CONCLUSIONS:

Part D beneficiaries with cardiovascular conditions with no financial assistance during the coverage gap were at increased risk for cardiovascular drug discontinuation; however, the impact of this difference on health outcomes is not clear.