Adherence and perception of medication in patients with chronic heart failure during a five-year randomised trial

ObjectiveMany patients with chronic heart failure (CHF) are thought to be non-adherent to their prescribed medications. The objective was to describe perceptions about and adherence to regular medicines and study medication at baseline and study end in CHF patients participating in a clinical trial.MethodsIn the carvedilol or metoprolol European trial (COMET), patients (N = 3029) with CHF were randomised and followed during a 58-month period. Patients at some Swedish centres answered a questionnaire at baseline and study end concerning their perception of their regular heart medication and study medication. Adherence was established through estimation of drug usage.ResultsIn the Swedish sub-study, 302 patients responded once to the questionnaire while 107 patients responded both at baseline and at follow-up. At baseline, 94% of the patients stated that they believed that the study medication would make them feel better and 82% believed that their regular heart medication would do so. During the study, patients’ belief in their regular cardiac medication significantly increased. Lack of belief in medication at the start of the study was a strong predictor of withdrawal from the trial (64% versus 6.8%; p < 0.0001). Those patients with very poor well-being and limited functional ability (classified as NYHA III–IV) at baseline significantly (p = 0.01) increased their belief in the regular cardiac medication but not in their study medication.ConclusionBelief in medication may be related to how the patient experiences the medication's impact on functional ability, symptoms and well-being.Practice implicationsEarly identification of patients’ beliefs about medication seem to be an important factor in counselling and information to patients with CHF.