Abstract 112: Depression Does Not Predict Longitudinal Medication Adherence in an Acute Coronary Syndrome Population

Abstract

Background: Prior studies have shown that depression may be associated with longitudinal medication non-adherence for patients with chronic cardiovascular disease. However, little is known about depression and medication adherence following acute coronary syndrome (ACS) hospitalization. Our objective was to assess whether depression was associated with longitudinal medication adherence following ACS among Veterans enrolled in a clinical trial designed to improve medication adherence. Methods: Patients included in the current analysis were enrolled in the MEDICATION study, which tested a multifaceted intervention versus usual care to improve medication adherence in the year following ACS hospitalization at 4 VA Medical Centers. Depression was assessed using the Patient Health Questionnaire (PHQ-9) prior to hospital discharge based on a score of ≥10. Medication adherence was assessed for 4 classes of cardioprotective medications (Statins, ACEI/ARBs, Clopidogrel, and Beta Blockers) in the 12-months following hospital discharge using pharmacy refill data. A proportion of days covered (PDC) was calculated based on the 4 classes of medications, and adherent patients were categorized based on a PDC ≥0.80. Then, we assessed the association between depression and medication adherence in the year after ACS hospitalization. Results: Of the 241 patients, the average age was 63.9 years, mean BMI was 30.9 kg/m 2 , and they had a number of comorbidities: 45.2% had diabetes and 65.6% had a history of coronary artery disease. The mean PHQ-9 score was 8.2 and 35.4% had depression (PHQ≥10) prior to discharge, with no difference in the prevalence of depression between treatment groups. In the year after ACS hospitalization, the mean PDC was 0.90 for all patients and there was no difference between depressed (PDC=0.91) and non-depressed patients (PDC=0.90). Among patients in the usual care group, there was also no difference in adherence between depressed (PDC=0.88) and non-depressed (PDC=0.86) patients. Conclusions: In this cohort of patients enrolled in a clinical trial, depression was present in 1 out of 3 patients during ACS hospitalization but not associated with medication adherence in the year after hospital discharge. A potential explanation for the lack of association between depression and adherence may be related to the overall high adherence rates found in the MEDICATION study. It will be important to assess whether depression is a marker of medication non-adherence in other ACS cohorts.