Trends in Mail-Order Pharmacy Use in the U.S. From 1996 to 2018: An Analysis of the Medical Expenditure Panel Survey

Abstract

The use of mail-order pharmacies is generally associated with lower healthcare costs and improved medication adherence. To promote the use of mail-order pharmacies, it is important to understand the time trends in their use and whether these trends vary by population subgroups. This study used the 1996-2018 Medical Expenditure Panel Survey to determine the annual prevalence of mail-order pharmacy use (defined as purchasing ≥1 prescription from a mail-order or online pharmacy) among U.S. adult prescription users and its variation by population characteristics. Logistic regression was used to determine the correlates of mail-order pharmacy use. Results were presented for medications and therapeutic classes most commonly purchased by mail-order pharmacy exclusive users. Analyses were conducted in December 2020. The annual prevalence of mail-order pharmacy use among U.S. adult prescription users increased from 10.2% (95% CI=9.3, 11.1) in 1996 to 17.0% (95% CI=15.9, 18.1) in 2005 and then declined to 15.7% (95% CI=14.9, 16.6) by 2018. Absolute differences in the prevalence of use by race/ethnicity, education, and health insurance coverage widened over time, whereas they remained stable when stratifying by sex, age, marital status, region, limitations in daily activities, pain interference, health status, number of chronic conditions, and access to medical care. Among mail-order pharmacy exclusive users, the 3 most commonly purchased medications were atorvastatin (16.7%), levothyroxine (13.6%), and lisinopril (13.1%); the 3 most commonly purchased therapeutic classes were cardiovascular agents (57.9%), metabolic agents (52.1%), and central nervous system agents (29.6%). The prevalence of mail-order pharmacy use has declined in recent years and has shown significant variation across population subgroups. Future research should examine whether the declining trends and variation in use may influence the management of chronic conditions and the disparities in health and healthcare costs.