OBJECTIVES: The objective of this study was to identify determinants of increasing medication expenditures in the US between 2011 and 2020.

METHODS: This was a cross-sectional analysis of prescription medication expenditures extracted from the 2011-2020 Medical Expenditures Panel Survey (MEPS). Total annual antidiabetic expenditures were calculated for each of the following payer categories: Out-of-pocket, Medicare, Medicaid, TRICARE/Veterans Administration/CHAMPVA (TVAC), Other Government Sources, Private Insurance, and Other Sources. Totals were weighted to account for MEPS design elements and ordinary linear regression, stratified by payer type, was used to estimate trends in annual total antidiabetic expenditures between 2011 and 2020. Inflation was adjusted to US dollar (USD) in 2020.

RESULTS: Increasing trends in total prescribed medication expenditures were observed between 2011-2020 ($341.49-$473.12 billion. P <0.0001). Within the prescribed medicines, metabolic agents comprised the largest expenditure above other drug categories for the duration. Within the metabolic agents, the antidiabetic agents comprised the largest expenditure for the duration. An increasing trend in antidiabetic agent expenditure was observed for the duration 2011-2020 ($27.15 - $89.17 billion, P<.0001). In observing the source of payment categories in antidiabetic agent expenditures, an increasing trend was observed for Medicare ($7. - $38.23 billion, P <.0001), Medicaid ($2.65 - $8.86 billion, P =. 001), Private Insurance ($9.91 - $33.80 billion, P<.0001), TVAC ($0.75 - $1.51 billion, P =.03), and Other sources ($0.12 - $0.37 billion, P =.009). No trend was observed for Out-of-pocket (P=.93) and Other Government Sources (P =.08). Insulin comprised the largest expenditure above other antidiabetic agents for the duration in Out-of-pocket, Medicare, Medicaid, Private Insurance and Other Government Resources.

CONCLUSIONS: The total antidiabetic agent expenditure as well as the respective amounts for Medicare, Medicaid, Private Insurance, TVAC and other sources increased between 2011 and 2020. Further studies are warranted to explore specific factors contributing to the increasing trend.