ORIGINAL ARTICLE Self-reported versus ‘true ’ adherence in heart failure patients: a study using the Medication Event Monitoring System

# The Author(s) 2012. This article is published with open access at Springerlink.com Background Adherence to (non)pharmacological treatment is important in heart failure (HF) patients, since it leads to better clinical outcome. Although self-reported and objec-tively measured medication adherence in HF patients have been compared in previous studies, none of these studies have used an evidence-based cutpoint to differentiate be-tween adherence and non-adherence. Methods In 37 HF patients (mean age 68±10 years, 27 % female, 40 % NYHA functional class III-IV), medication (ACEi/ARB) adherence was objectively measured using the Medication Event Monitoring System (MEMS). Adherence to and importance of taking medication was also assessed by self-report using the Revised HF Compliance Questionnaire. Results All patients reported that adherence was (highly) important to them and that they ‘always ’ took their medica-tion as prescribed (i.e. 100 % adherence). However, when measured by the MEMS, only 76 % of all patients were adherent. Non-adherent patients more often had a complex medication regimen (78 % vs. 21 %, P<.01), more often depressive symptoms (75 % vs. 29 %, P0.04) and a shorter history of HF (8 vs. 41 months, P0.04), compared with adherent patients. Conclusions Medication adherence measured by the MEMS was remarkably lower than self-reported adherence. Given the evidence of its importance, further efforts are needed to improve adherence to the pharmacological regi-men in HF patients