Title: Specialty Pharmacy Adherence Optimization: Evaluating Adherence Using Medication Possession Ratio
Authors: Lily M. Frappier, PharmD; Katheryn A. Fierros, CPhT, MBA; Emmaline R. Libby, PharmD, CSP; Gabrielle N. Plaia, PharmD, CSP; Wen Jie J. Song, PharmD, BCPS
Learning Objective: At the conclusion of this presentation, the audience will be able to evaluate the impact of medication possession ratio (MPR) reports on optimizing medication adherence in patients with Cystic Fibrosis (CF), Human Immunodeficiency Virus (HIV), and Multiple Sclerosis (MS)
Self-Assessment Question: What is a calculation commonly used in specialty pharmacy to measure patient adherence?
- Medication Possession Ratio
- Medication Therapy Management
- Total number of prescriptions written
- Defined Daily Dose
Background/Objective: Adherence to specialty medications is essential for optimal management of chronic conditions such as CF, HIV, and MS. Low adherence is associated with higher rates of exacerbations, hospitalizations, healthcare costs, and reduced quality of life. The primary objective of this quality improvement initiative was to develop a best practice model to identify patients with suboptimal adherence using MPR analysis and subsequently implement targeted interventions to improve adherence. Secondary objectives included evaluating changes in MPR from baseline to post-intervention and identifying demographic trends that may correlate with higher non-adherence risk.
Methods: This prospective quality improvement project included patients enrolled in CF, HIV, or MS programs through Compass Rose™ who received medications through Dartmouth-Hitchcock (DH) Specialty Pharmacy and had an MPR < 80%. Patients were excluded if their MPR ≥ 80% or if, they did not fill their specialty prescriptions through DH Specialty Pharmacy. From August 2025 to January 2026, bi-weekly pharmacy dispensing reports identified patients with an MPR < 80%. Comprehensive chart reviews were conducted to confirm true non-adherence by excluding cases of artificially low MPR due to factors such as insurance barriers, hospitalization, early refills, change in care, and specialty opt-out status. Pharmacist-led outreach interventions were initiated for patients confirmed to be non-adherent, and medication therapy problems (MTPs) were documented after successful outreach to the patient. During outreach efforts, pharmacists assessed medication-taking behaviors, evaluated ongoing adherence risk, and documented related MTPs. A Plan-Do-Study-Act (PDSA) framework was utilized throughout the project to continually refine the intervention process. Baseline and post-intervention MPR scores were compared to assess adherence improvement. Additional analyses evaluated demographic and disease-specific trends associated with non-adherence.
Results: This initiative enabled the development of a best-practice model to identify non-adherent patients with CF, HIV, and MS. Of the 72 patients meeting inclusion criteria, 20 were identified as truly non-adherent following chart review. Interventions were implemented for all identified patients, however, 2 of the 20 patients were unreachable despite multiple outreach attempts. One patient who had previously opted out of DH Specialty refill services re-enrolled following pharmacist outreach. Secondary outcomes demonstrated that 3 of 20 patients showed improvement in MPR from baseline to the most recent assessment. There was no significant improvement in MPR across the study population. Additionally, no association was found between patient demographics and risk of non-adherence. The most frequently represented medications in the study included bictegravir-emtricitabine-tenofovir alafenamide fumarate, elexacaftor-tezacaftor-ivacaftor, emtricitabine-tenofovir disoproxil fumarate, and ofatumumab.
Conclusions: The integration of MPR report analysis can serve as a useful tool for identifying potential medication non-adherence and facilitating pharmacist-led interventions. This pilot successfully established a scalable best-practice model that could be applied across various specialty disease states. However, the intervention was not associated with a significant overall improvement in MPR. The short pilot duration (5 months) compounded by the larger number of days in the MPR measurement period (13 months) may have limited the ability to detect meaningful changes in adherence. Non-adherent patients typically require continuous follow up as well, rather than a single adherence reminder. While improvements in MPR were observed in a small subset of patients, a longer follow-up period and the addition of continuous adherence check-in interventions might be necessary to better evaluate the impact of pharmacist-led interventions on medication adherence and related clinical outcomes.
