Background: Eliminating out-of-pocket costs for patients after myocardial infarction (MI) improves adherence to preventive therapies and reduces clinical events. Because adherence to medical therapy is low among patients treated with coronary artery bypass graft surgery (CABG), we evaluated the impact of providing full prescription coverage to this patient subgroup.
Methods and results: The MI Free Rx Event and Economic Evaluation (FREEE) trial randomly assigned 5855 patients with MI to full prescription coverage or usual formulary coverage for all statins, β-blockers, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers. We assessed the impact of full prescription coverage on adherence, clinical outcomes, and healthcare costs using adjusted models among the 1052 patients who underwent CABG at the index hospitalization and 4803 who did not. CABG patients were older and had more comorbid illness (P<0.01). After MI, CABG patients were significantly more likely to receive β-blockers and statins but were less likely to receive angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy (P<0.01). Receiving full drug coverage increased rates of adherence to all preventative medications after CABG (all P<0.05). Full coverage was also associated with nonsignificant reductions in the rate of major vascular events or revascularization for patients treated with CABG (hazard ratio, 0.91; 95% confidence interval, 0.66-1.25) or without CABG (hazard ratio, 0.93; 95% confidence interval, 0.82-1.06), with no interaction noted (Pint=NS). After CABG, full prescription coverage significantly reduced patient out-of-pocket spending for drugs (P=0.001) without increasing overall health expenditures (P=NS).
Conclusions: Eliminating drug copayments after MI provides consistent benefits to patients treated with or without CABG, leading to increased medication adherence, trends toward improved clinical outcomes, and reduced patient out-of-pocket expenses.
Keywords: coronary artery bypass graft surgery; prescription coverage; prevention.