Spending on antidiabetic drugs is the fastest growing component of the medical cost of diabetes in the U.S. What factors have contributed to the increase remains unclear. Using Medical Expenditure Panel Survey, we (1) estimated the increase in the national spending on antidiabetic drugs from 2005 to 2016; (2) examined magnitudes of contributing factors to the increase using a full decomposition method. The contributing factors were first grouped into insulin verse non-insulin, the former was grouped into human, analog, and premixed insulin and later was grouped into metformin, older drugs (sulfonylurea, thiazolidinediones, alpha-glucosidase inhibitor, and meglitinides), newer drugs (dipeptidyl peptidase-4 inhibitor, amylin analog, glucagon-like peptide-1, and sodium-glucose contransporter-2), and combinations. Spending on insulin and non-insulin was also decomposed into number of users and expenditure per user. National spending increased by $38.7 billion from 2005 to 2016 (Figure). Most of the increase was due to insulin, mainly analog insulin. Increases in noninsulin was a net effect of an increase in newer drugs and a fall in older drugs. Higher spending per user was the main driver for insulin and both more users and lower expenditure per user led to the increase on noninsulin. Understanding the driving factors can help identify ways to slow down the growth in antidiabetic drug expenditures.
X. Zhou: None. S. Shrestha: None. H. Shao: None. P. Zhang: None.