Abstract 182: Medication Adherence Based on Part D Claims for Heart Failure Patients after Hospitalization in the Atherosclerosis Risk in Communities Study

Abstract

Purpose: Recent analyses of national data have focused on long-term adherence in heart failure (HF) patients. Little is known about adherence of HF patients immediately following hospitalization. Methods: Hospitalized patients with an adjudicated HF diagnosis were identified from the Atherosclerosis Risk in the Communities (ARIC) study, which has followed a biracial cohort of 15,792 participants from 4 US communities since 1987. Participants with an adjudicated hospitalization diagnosis of acute or chronic HF during March 2006 - December 2009 who were also enrolled in Medicare Part D for at least 3 months prior to hospitalization were included. Part D prescriptions filled were identified using National Drug Codes and analyzed by sub-groups of patients discharged on ACE inhibitors/angiotensin receptor blockers (ACEI/ARB), beta-blockers (BB), or diuretics. Proportion days covered (PDC) was calculated for up to twelve 30-day periods after discharge. PDC was based on days outside of a hospital or skilled nursing facility. Observations were censored by death or end of study period. Results: The study sample included 431 HF patients with mean age of 75 years (range 63 to 86), 36% male, and 41% African-American. Of the total patients, 67% were discharged on ACEI/ARB, 79% on BB, and 83% on a diuretic. Among those with discharge medications, some persons never filed Part D claims during the 12 periods (29/287 for ACEI/ARB, 25/340 for BB and 32/357 for diuretics). ACEI/ARB PDC after discharge declined from 74% to 57% over time (Figure 1); BB and diuretics had similar results. Patients with ACEI/ARB PDC>0 during the first 30 day period after discharge had higher PDC for subsequent periods, declining from 92% to 65%. The greatest decline in PDC occurred during the first 2-4 months after discharge for all medications. Conclusions: This study has many advantages over some prior studies. HF diagnosis was not defined simply by ICD9 codes. Discharge medications were documented, so Part D claims were not used to identify patients. Part D claims may be missing for some medications taken (e.g., $4 generic plans, provider samples), but ACEI/ARB PDC still declined 27 percentage points among patients with Part D PDC>0 immediately post-discharge. Interventions should be developed to assure early and sustained medication adherence.