OBJECTIVES: Being adherent to medications is necessary for optimal therapeutic efficacy but nonadherence remains a significant public health issue. Primary medication nonadherence (PMN) is when a new prescription is filled and not picked up; prescription abandonment encompasses both new and refilled prescriptions. Previous research shows PMN rates of 3-10%, but currently, there isn’t a consensus to prescription abandonment rates despite interchangeable use of the terms. This research aims to quantify the rates of prescription abandonment in the literature.

METHODS: A review of the literature using PubMed was conducted using the following terms: prescription abandonment, unclaimed prescriptions, primary medication nonadherence, and primary nonadherence.

RESULTS: A total of 168 articles were found. 22 were duplicates. After two rounds of independent reviews with two reviewers, 37 articles were included in the final review. Only 7 articles explicitly included refills in their analysis, with abandonment rates ranging from 0.82% to 54.2%. For articles (n=30) that focused on medication initiation, primary medication nonadherence rates ranged from 4-65.5%, with most of the recent literature focusing on specific therapies (e.g., TNF blockers, PCSK9s, ALK inhibitors) or specific diagnoses (e.g., oncology, hyperlipidemia, hepatitis C). The most recent article to be inclusive of all medications and conditions was published in 2017, using data covering 3 nonconsecutive months in 2015, showing a general abandonment rate of 13.7%.

CONCLUSIONS: A review of the literature did not result in a quantification of abandonment rates that are inclusive of all therapeutic medications on the market. Prescription drug prices continue to rise, and expensive medications are likely to be abandoned. Identifying prescription abandonment rates is necessary to address the issue effectively and efficiently and ultimately, improve health outcomes.