Adherence to the medical regime in patients with heart failure

Abstract

Aims To assess adherence to medical treatment in patients with heart failure (HF) using a specific questionnaire and measurement of the serum concentration of digoxin.Methods and resultsForty patients with symptomatic HF and a clinical indication for digoxin were included in this pilot study. The assessment of adherence to the medical regime was based on two different methods: (i) the CARDIA-Questionnaire and (ii) the measurement of serum digoxin concentration (SDC) at 1 and 6 months. All patients were placed on digoxin treatment (target SDC 0.6-0.8 ng/mL) at baseline. Poor adherence was defined if the patient self-reported taking ≤75 of the prescribed HF medication or had an SDC < 0.4 ng/mL (subtherapeutic range) at the follow-up visits. During the entire follow-up, the proportion of patients with poor adherence was 15 as assessed by the questionnaire, 20 as assessed by the SDC, and 25 if both methods were combined.ConclusionAlthough HF is a symptomatic disease, the proportion of patients with poor adherence to the medical regime in our study was high (up to 25). The objective methodology based on the measurement of the SDC identified a higher number of patients with poor adherence when compared with the CARDIA-Questionnaire. © The Author 2010.