Factors Contributing to the Rising National Cost of Glucose-Lowering Medicines for Diabetes During 2005-2007 and 2015-2017

Abstract

Objective: We examined changes in glucose-lowering medication spending and quantified the magnitude of factors that are contributing to these changes.

Research design and methods: Using the Medical Expenditure Panel Survey, we estimated the change in spending on glucose-lowering medications during 2005-2007 and 2015-2017 among adults aged ≥18 years with diabetes. We decomposed the increase in total spending by medication groups: for insulin, by human and analog; and for noninsulin, by metformin, older, newer, and combination medications. For each group, we quantified the contributions by the number of users and cost-per-user. Costs were in 2017 U.S. dollars.

Results: National spending on glucose-lowering medications increased by $40.6 billion (240%), of which insulin and noninsulin medications contributed $28.6 billion (169%) and $12.0 billion (71%), respectively. For insulin, the increase was mainly associated with higher expenditures from analogs (156%). For noninsulin, the increase was a net effect of higher cost for newer medications (+88%) and decreased cost for older medications (-34%). Most of the increase in insulin spending came from the increase in cost-per-user. However, the increase in the number of users contributed more than cost-per-user in the rise of most noninsulin groups.

Conclusions: The increase in national spending on glucose-lowering medications during the past decade was mostly associated with the increased costs for insulin, analogs in particular, and newer noninsulin medicines, and cost-per-user had a larger effect than the number of users. Understanding the factors contributing to the increase helps identify ways to curb the growth in costs.

Figure 1

Contribution (in percentage points and dollar values in 2017 U.S. dollars, billions) of medication groups to the increase in total glucose-lowering medication spending, 2005–2007 to 2015–2017. *Older noninsulin medications include sulfonylureas, thiazolidinediones, α-glucosidase inhibitors, and meglitinides. †Newer noninsulin medications include DPP-4, amylin analog, GLP-1, and SGLT2. ‡A combination medication is a single pill with a fixed-dose combination of two or more active pharmaceutical ingredients.