Evaluation of a pharmacist-driven medication adherence enhancement service

Area of Science:

• Health Services Research
• Pharmaceutical Care
• Clinical Pharmacy

Background:

• Limited data exist on the impact of primary care-embedded pharmacists on medication adherence and Medicare Part D star ratings.
• Key adherence measures include diabetes, hypertension (renin-angiotensin-system antagonists), and cholesterol (statin) medications.
• Proportion of Days Covered (PDC) is a critical metric for assessing medication adherence.

Purpose of the Study:

• To evaluate the impact of pharmacist-integrated primary care on medication adherence.
• To assess the difference in the percentage of beneficiaries achieving a PDC of 80% or higher between an intervention and control group.
• To determine the potential influence on Medicare Part D star ratings.

Main Methods:

• Retrospective cohort study using Humana Medicare Advantage Part D data from 2019.
• Intervention group: Patients receiving pharmacist outreach in Colorado primary care clinics.
• Control group: Propensity score-matched Arizona patients; pharmacists used telephonic outreach, patient education, and collaborative practice agreements.

Main Results:

• The adherence prioritization group showed a higher percentage of patients with PDC ≥ 80% (71.0%) compared to the control group (62.3%), a statistically significant difference of 8.6%.
• End-of-year adherence rates for the intervention group were 88% (diabetes), 89% (hypertension), and 89% (cholesterol).
• Control group end-of-year adherence rates were 85% (diabetes), 88% (hypertension), and 87% (cholesterol).

Conclusions:

• Pharmacist-driven interventions effectively improve medication adherence and Proportion of Days Covered (PDC).
• Improvements in PDC can positively influence Medicare Part D star ratings.
• Even small improvements in adherence metrics can be significant for achieving higher star ratings.