Background: Patients with heart failure who take several prescription medications sometimes have poor adherence to their treatment regimens. Few interventions designed to improve adherence to therapy have been rigorously tested.
Objective: To determine whether a pharmacist intervention improves medication adherence and health outcomes compared with usual care for low-income patients with heart failure.
Design: Randomized, controlled trial conducted from February 2001 to June 2004.
Setting: University-affiliated, inner-city, ambulatory care practice.
Patients: 314 low-income patients 50 years of age or older with heart failure confirmed by their primary care physician.
Intervention: Patients were randomly assigned to intervention (39% [n = 122]) or usual care (61% [n = 192]) groups and were followed for 12 months. A pharmacist provided a 9-month multilevel intervention, with a 3-month poststudy phase. An interdisciplinary team of investigators designed the intervention to support medication management by patients who have low health literacy and limited resources.
Measurements: Primary outcomes were adherence, as measured by using electronic prescription monitors, and exacerbations requiring emergency department care or hospital admission. Secondary outcomes included health-related quality of life, patient satisfaction with pharmacy services, and total direct costs.
Results: During the 9-month intervention period, medication adherence was 67.9% and 78.8% in the usual care and intervention groups, respectively (difference, 10.9 percentage points [95% CI, 5.0 to 16.7 percentage points]). However, these salutary effects dissipated in the 3-month postintervention follow-up period, in which adherence was 66.7% and 70.6%, respectively (difference, 3.9 percentage points [CI, -5.9 to 6.5 percentage points]). Medications were taken on schedule 47.2% of the time in the usual care group and 53.1% of the time in the intervention group (difference, 5.9 percentage points [CI, 0.4 to 11.5 percentage points]), but this effect also dissipated at the end of the intervention (48.9% vs. 48.6%, respectively; difference, 0.3 percentage point [CI, -5.9 to 6.5 percentage points]). Emergency department visits and hospital admissions were 19.4% less (incidence rate ratio, 0.82 [CI, 0.73 to 0.93]) and annual direct health care costs were lower ($-2960 [CI, $-7603 to $1338]) in the intervention group.
Limitations: Because electronic monitors were used to ascertain adherence, patients were not permitted to use medication container adherence aids. The intervention involved 1 pharmacist and a single study site that served a large, indigent, inner-city population of patients. Because the intervention had several components, intervention effects could not be attributed to a single component.
Conclusions: A pharmacist intervention for outpatients with heart failure can improve adherence to cardiovascular medications and decrease health care use and costs, but the benefit probably requires constant intervention because the effect dissipates when the intervention ceases. ClinicalTrials.gov registration number: NCT00388622.