The algorithm by which primary medication nonadherence is traditionally defined overestimates the true rate of primary medication nonadherence, according to a study presented at the virtual 2020 National Association for Specialty Pharmacy (NASP) Annual Meeting & Expo.
“Primary medication nonadherence is the rate at which a prescription is written, but not obtained by a patient within a specified time period,” explained Autumn Zuckerman, MD, PharmD, BCPS, AAHIVP, CSP, Vanderbilt Specialty Pharmacy, Nashville, Tennessee, during her presentation.
“It is of particular interest in specialty pharmacy due to the complex medication access process and the high cost of a lot of these medications,” she continued.
A single-center retrospective cohort analysis was performed for prescriptions written at Vanderbilt University Medical Center for specialty oral oncolytic, which were electronically sent to Vanderbilt Specialty Pharmacy between January and December of 2018.
Primary medication nonadherence was defined using the following parameters: a lookback window of 180 days to assess if a patient was treatment-naïve, a duplicate window of 2 days, and a fill window of 30 days.
Primary medication nonadherence was calculated based on pharmacy claims. A chart review was then performed to assess for reasons for primary medication nonadherence.
A total of 4,482 prescriptions were evaluated, of which 1,004 met eligibility criteria. Of these, 198 (19.7%) were considered potential instances of primary medication nonadherence, based on pharmacy claims and our primary medication nonadherence definitions.
Upon chart review, however, we found that 161 were actually misidentified as primary medication nonadherence. The primary reasons for primary medication nonadherence were due to being rerouted to an external pharmacy or filled by a manufacturer.
Overall, 37 prescriptions were found to be truly nonadherent, and most of these were due to a patient decision not to pick up, a medication change, or clinical decline. The true rate of primary medication nonadherence was actually 3.7%.
“Our conclusions for this study were that the algorithm by which primary medication nonadherence is traditionally defined grossly overestimates the true rate of primary medication nonadherence at a health system specialty pharmacy,” stated Dr Zuckerman.
“Overall, the rate of primary medication nonadherence for oral oncolytic at a health system specialty pharmacy was very low, and mostly due to medication change, clinical decline, or patient decision,” she concluded.—Janelle Bradley
McDonald A, Reynolds V, Shah N, et al. Reasons for Primary Medication Non-Adherence in Oncology Specialty Medications. Virtual NASP 2020 Annual Meeting and Expo. Presented September 17, 2020. Accessed September 29, 2020.
