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

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.