Pharmacist intervention can improve medication adherence in patients with heart failure

An educational intervention delivered by pharmacists can improve patients' adherence to medication for heart failure, but only as long as it is ongoing according to a controlled trial from the US. A major proportion of the cost of caring for patients with heart failure comes from the treatment of exacerbations: appropriate medication can reduce the frequency of exacerbations, however regimens are often complex with a number of drugs to be taken. Patients may find adherence to such regimens difficult, and this study aimed to determine whether an educational intervention delivered by the pharmacist dispensing the patient's routine medication could improve adherence. It was carried out in a large academic primary care centre in an economically disadvantaged area and involved patients with heart failure seen by general medical or cardiology clinics or after hospital discharge, who were randomised to intervention or usual care. Patients receiving their care from the centre get prescribed medicines from a central pharmacy or one of several associated satellites. For the purpose of the study, the central pharmacy was moved to be adjacent to the general medicine clinics treating heart failure patients: it was staffed with two pharmacists, the study pharmacist who saw all intervention patients, and another pharmacist who saw usual care group.

The study pharmacist reviewed each intervention patient's medication history and their level of medication knowledge and skills. Based on this, they were provided with personalised verbal and written education about their medication and how to take it. Primary outcomes were medication adherence (measured using electronic container lids) and clinical exacerbations requiring emergency department treatment or hospitalisation. Study duration was one year overall, with a nine month intervention period and three months post-intervention.

A total of 314 patients were randomised from 1,512 potentially eligible. Study patients were slightly younger (63 vs. 67) and more likely to be women (67% vs. 59%) than those in the potentially eligible group, however they were similar to heart failure patients seen by the centre overall (n=3,034). Of the study group, 192 were randomised to usual care and 122 to the intervention. Adherence to medication was significantly greater in the intervention group than in the control: 78.8% vs. 67.9% (difference 10.9 percentage points; 95% CI, 5.0 to 16.7 percentage points) actually took their medication and 53.1% vs. 47.2% (difference, 5.9 percentage points; 95% CI, 0.4 to 11.5 percentage points) took their medication near the scheduled times. The effect dissipated fairly rapidly, however, as the differences were not significant by the end of the post-intervention period. Patients in the intervention group were 19.4% less likely to have an exacerbation requiring emergency department visit or hospitalisation (incidence rate ratio, 0.82; 95% CI, 0.73 to 0.93) and had lower healthcare costs over the study period.

Based on their results, the authors conclude that a pharmacist intervention for outpatients with heart failure can improve medication adherence. This can reduce exacerbations and consequently costs, however it probably requires to be ongoing as the effect dissipated rapidly after the end of the study. The cost of the intervention was associated mainly with setting it up, and as more patients received it the cost per patient reduced: the authors calculate that it gave a return on investment of 14 times. They suggest that the results are consistent with those of previous studies looking at similar pharmacist and multidisciplinary interventions, however the interventions in this study was less comprehensive or intensive than most previous work.

Ann Intern Med 2007; 146: 714-25 (link to abstract)