Improving medication adherence in patients with hypertension: a randomized trial

BACKGROUND: and Purpose: In patients with hypertension, medication adherence is often suboptimal, thereby increasing the risk of ischemic heart disease and stroke. In a randomized trial, we investigated the effectiveness of a multifaceted pharmacist intervention in a hospital setting to improve medication adherence in hypertensive patients. Motivational interviewing was a key element of the intervention.

METHODS: Patients (N=532) were recruited from 3 hospital outpatient clinics and randomized to usual care or a 6-month pharmacist intervention comprising collaborative care, medication review, tailored adherence counselling including motivational interviewing and telephone follow-ups. The primary outcome was composite medication possession ratio (MPR) to antihypertensive and lipid-lowering agents, at one-year follow-up, assessed by analyzing pharmacy records. Secondary outcomes at 12 months included persistence to medications, blood pressure, hospitals admission and a combined clinical endpoint of cardiovascular death, stroke or acute myocardial infarction.

RESULTS: At 12 months, 20.3% of the patients in the intervention group (N=231) were non-adherent (MPR < 0.80) compared with 30.2% in the control group (N=285) (RD -9.8 (95% CI -17,3;-2.4) and median MPR (IQR) was 0.93 (0.82-0.99) and 0.91 (0.76-0.98), p=0.02. The combined clinical endpoint was reached by 1.3% in the intervention group and 3.1% in the control group (RR 0.41 [95% CI, 0.11-1.50]. No significant differences were found for persistence, blood pressure or hospital admission.

CONCLUSIONS: A multifaceted pharmacist intervention in a hospital setting led to a sustained improvement in medication adherence for patients with hypertension. The intervention had no significant impact on blood pressure and secondary clinical outcomes.