Primary medication nonadherence to oral oncology specialty medications

Patients prescribed specialty oncology medications face logistical and financial challenges to medication procurement, leading to primary medication nonadherence (PMN). Limited research has evaluated rates and reasons for PMN within a specialty oncology population. Addressing PMN is essential to ensuring patient access and uptake and realizing benefits of these therapies.

The objectives of this study were to compute the rates of and reasons for PMN in patients prescribed oral oncology medications at an integrated health-system specialty pharmacy (IHSSP).

We performed a single-center, retrospective analysis of specialty oncology prescriptions electronically prescribed between January and December 2018. Data were extracted from electronic health record (EHR) and pharmacy claims databases. Prescriptions were PMN eligible if none of the following were met: fill of any cancer medication within the previous 180-day lookback window, duplicate prescription, cancellation within 30 days, rerouting to an external pharmacy within 30 days of prescribing, filled through alternate method, or nononcology or hematology condition. PMN was calculated by dividing eligible prescriptions unfilled during the study period by all eligible prescriptions. Reasons for a lack of prescription fulfillment were assessed via EHR review. Data were analyzed using descriptive statistics.

We evaluated 4482 prescriptions from 1422 patients, resulting in 861 PMN-eligible prescriptions. Most PMN-eligible prescriptions (n = 668, 78%) were filled within 30 days, leaving 193 prescriptions as potential instances of PMN. After EHR review, 158 prescriptions met the exclusion criteria, resulting in a PMN rate of 4%. Of PMN prescriptions (n = 35), most were caused by clinical reasons (n = 22, 63%); however, 10 prescriptions were unfilled owing to patient decision, 2 owing to unaffordable treatment, and 1 owing to inability to reach the patient. Patients with PMN had a median age of 72 years and were mostly male (60%), with a median Charlson comorbidity index score of 7.

Low rates of PMN to prescribed anticancer medications were found among electronic prescriptions intended to be filled at an IHSSP.