Medication Costs and Cost-Related Nonadherence Among Patients With Diabetes in the United States

OBJECTIVES: Medications are crucial for diabetes management while they are associated with substantial financial costs for healthcare system and patients, raising concerns about affordability. Understanding the trends and driving factors behind medication costs is imperative for improving the cost-effectiveness of medication use for diabetes.

METHODS: We conducted a series of cross-sectional analysis using data from the Medical Expenditure Panel Survey (MEPS) from 2016 to 2021. Adults with diabetes were included. Medication expenditures of the overall, by therapeutic classes, by Medicare and out-of-pocket (OOP) were examined. We further examined the association between medication costs and cost-related nonadherence (CRN).

RESULTS: A total of 18,480 adults with diabetes were included in our study. The inflation-adjusted average medication costs per patient increased from $5393 in 2016 to $6370 in 2021, with decreasing payment by OOP ($576 to $418) and increasing payment by Medicare ($2600 to $3054). The increase was mainly driven by non-insulin antidiabetic medications, insulin, and coagulation modifiers. Anti-diabetic medications accounted for approximately 50% of costs (46.5% in 2016 to 58.7% in 2021), with insulin accounting for 13.4% and non-insulin medications for 45.3% in 2021 (VS. 32.8% in 2016). Non-antidiabetic medications accounted for approximately 50% of medication costs, with the highest expenditures attributed to coagulation modifiers (2.8% VS. 6%), cardiovascular drugs (8.1% to 3.4%), and central nervous system drug (7.1% to 4.0%). Antilipidemic and antihypertensive medication each accounted for around 2% of costs. A total of 6.7% of diabetic patients reported CRN, higher out-of-pocket medication spending was associated with a significantly greater risk of CRN (odds ratio, 2.8 [2.3-3.4]).

CONCLUSIONS: Patients with diabetes face a substantial and increasing financial burden from prescription medications. Both antidiabetic and non-diabetic medications contributed substantially to the costs, and such high burden may impact patients’ adherence to medication. The rapid growth in costs of some medication deserves attention from payers and policymakers.