Interventions to Enhance Adherence to Medications in Patients With Heart Failure

Abstract

Prognosis remains poor for patients with chronic heart failure (CHF), despite improvements in the prevention and treatment of heart failure over the last 25 years. Recent estimates indicate that the median survival after a first episode of heart failure is 2.3 years for men and 1.8 years for women.1 It is suggested that the improvements in outcomes that have been achieved can be partly explained by increases in prescribing rates of medications such as angiotensin-converting enzyme inhibitors,2 β-blockers,3 and spironolactone4 over this period.1 Although the evidence on medication efficacy for certain subgroups of patients with CHF is clear, there are also compelling data showing that many of these patients do not take their medications as prescribed by health care providers.5,6 This “nonadherence” to medication therefore remains a significant barrier to enhancing the effectiveness of existing treatments. Estimates for nonadherence to medications in CHF have varied widely.5 One of the largest studies found that only 80% of patients with a prescription for angiotensin-converting enzyme inhibitors at hospital discharge completed the prescription form 30 days after discharge, and this rate subsequently fell to 60% over 1 year.7 Full adherence, defined as filing enough prescriptions to have daily medication available for 1 year, may be as low as 10% in CHF.8 Poor adherence to medication in CHF is associated with worse outcomes in observational studies, including shorter event-free survival.9 Therefore, strategies to enhance adherence provide a potentially valuable strategy for improving survival, reducing hospitalization and managing patient symptoms in CHF. In this report, we provide an up-to-date review and analysis of those studies that have developed and evaluated medication adherence interventions in CHF. Because CHF is typically symptomatic and includes medication with actions that are discernible to the patient within hours …