Evaluation of community pharmacist-provided telephone interventions to improve adherence to hypertension and diabetes medications

Abstract

Objectives: To 1) identify specific patient barriers and pharmacist interventions to medication adherence by means of the Drug Adherence Work-Up (DRAW) tool; and 2) measure patient adherence to antihypertensive and antidiabetic medications by calculating proportion of days covered (PDC) before and after pharmacist telephone adherence interview.

Design: This prospective quality-improvement study consisted of telephonic interviews and targeted interventions to increase medication adherence based on patient-specific barriers. The baseline PDC was electronically calculated for each patient, and postintervention PDCs were manually calculated at 90 days and 180 days after baseline. The measurement period in each PDC calculation was 180 days.

Setting and patients: This study was conducted in a small-chain independent pharmacy in rural Midwest United States. Patients taking an antihypertensive or oral antidiabetic medication were identified through an online platform and contacted if they had a PDC of less than 80% during the previous 180 days.

Outcome measures: Baseline and postinterview PDC were calculated for each patient who received an adherence interview. Frequency of specific barriers and pharmacist interventions were identified and analyzed.

Results: Ninety-seven eligible patients were identified. Fifty-six patients participated in an interview. Of these, a total of 66 barriers to adherence were identified. Pharmacists implemented 76 interventions for these patients, and 43 patients were included in final PDC calculations. From baseline, 69.0% of patients with hypertension and 64.3% of patients with diabetes reached a PDC of greater than 80% within 3 months. The most frequently identified barrier was forgetfulness on routine days, and the most common interventions were patient education, deactivated drug, and recommend or start medication synchronization program.

Conclusion: Using pharmacists to identify and address patient barriers to adherence resulted in a significant increase in PDC among patients with hypertension and diabetes. The DRAW tool can be used in a community pharmacist-delivered telephonic intervention to improve medication adherence.