Medication Adherence Based on Part D Claims for Patients with Heart Failure after Hospitalization (from the Atherosclerosis Risk in Communities Study)

Medication nonadherence is a common precipitant of heart failure (HF) hospitalization and is associated with poor outcomes. Recent analyses of national data focus on long-term medication adherence. Little is known about adherence of patients with HF immediately after hospitalization. Hospitalized patients with HF were identified from the Atherosclerosis Risk in Communities study. Atherosclerosis Risk in Communities data were linked to Medicare inpatient and part D claims from 2006 to 2009. Inclusion criteria were a chart-adjudicated diagnosis of acute decompensated or chronic HF; documentation of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB), β blocker (BB), or diuretic prescription at discharge; and Medicare part D coverage. Proportion of ambulatory days covered was calculated for up to twelve 30-day periods after discharge. Adherence was defined as ≥80% proportion of ambulatory days covered. We identified 402 participants with Medicare part D: mean age 75, 30% men, and 41% black. Adherence at 1, 3, and 12 months was 70%, 61%, and 53% for ACEI/ARB; 76%, 66%, and 62% for BB; and 75%, 68%, and 59% for diuretic. Adherence to any single drug class was positively correlated with being adherent to other classes. Adherence varied by geographic site/race for ACEI/ARB and BB but not diuretics. In conclusion, despite having part D coverage, medication adherence after discharge for all 3 medication classes decreases over 2 to 4 months after discharge, followed by a plateau over the subsequent year. Interventions should focus on early and sustained adherence.