Transitional adherence and persistence in the use of aldosterone antagonist therapy in patients with heart failure

Background Aldosterone antagonist therapy is recommended for selected patients with heart failure and reduced ejection fraction. Adherence to therapy in the transition from hospital to home is not well understood. Methods We identified patients with heart failure and reduced ejection fraction who were >= 65 years old, eligible for aldosterone antagonist therapy, and discharged home from hospitals in the Get With the Guidelines-Heart Failure registry between January 1, 2005, and December 31, 2008. We used Medicare prescription drug event data to measure adherence. Main outcome measures were prescription at discharge, outpatient prescription claim within 90 days, discontinuation, and adherence as measured with the medication possession ratio. We used the cumulative incidence function to estimate rates of initiation and discontinuation. Results Among 2,086 eligible patients, 561 (26.9%) were prescribed an aldosterone antagonist at discharge. Within 90 days, 78.6% of eligible patients with a discharge prescription filled a prescription for the therapy, compared with 13.0% of eligible patients without a discharge prescription (P < .001). The median medication possession ratio was 0.63 over 1 year of follow-up. Among 634 patients who filled a prescription within 90 days of discharge, 7.9% discontinued therapy within 1 year. Conclusion Most eligible patients were not prescribed aldosterone antagonist therapy at discharge from a heart failure hospitalization. Eligible patients without a discharge prescription seldom initiated therapy as outpatients. Most patients who were prescribed an aldosterone antagonist at discharge filled the prescription within 90 days and remained on therapy.