Ambulatory noninsulin treatment of type 2 diabetes mellitus in the United States, 2015 to 2019

Objective: To examine trends in the noninsulin drug treatment of type 2 diabetes, including first- and second-line therapies on top of metformin, from 2015 to 2019. Participants and Methods: We conducted a descriptive analysis of cross-sectional data using the IQVIA National Disease and Therapeutic Index, a nationally representative audit of ambulatory physician practices in the United States. We focused on the use of noninsulin pharmacological treatments for type 2 diabetes among individuals aged 35 years and older between January 1, 2015 and December 31, 2019. The main outcome was type 2 diabetes visits where a prescription drug was used (“treatment visit”). Results: Ambulatory diabetes visits decreased from 30.1 million treatment visits in 2015 to 29.5 million treatment visits in 2019. Among treatment visits where a single drug was prescribed, the use of metformin declined from 57.0% of monotherapy in 2015 to 46.0% of monotherapy in 2019, while during the same period the share of monotherapy accounted for by glucagon-like peptide-1 (GLP-1) receptor agonists increased from 4.3% to 8.5% and the share accounted for by sodium-glucose cotransporter-2 (SGLT2) inhibitors increased from 7.3% to 19.5%. Among treatment visits where metformin plus another drug was prescribed, the share of second-line therapy accounted for by dipeptidyl peptidase-4 (DPP-4) inhibitors decreased from 21.9% of treatment visits in 2015 to 20.8% of treatment visits in 2019; sulphonylurea use declined from 45.2% to 32.7%, use of SGLT2 inhibitors increased from 14.5% to 21.2% and use of GLP-1 receptor agonists increased from 9.8% to 18.2%. Conclusions: Significant changes in the landscape of ambulatory care for diabetes have taken place during the past 6 years, including moderate declines in metformin monotherapy, moderate declines in second-line sulphonylurea use, and large increases in SGLT2 use. These changes underscore the dynamic nature of drug utilization for diabetes in the United States, and reflect the effects of emerging evidence, evolving clinical guidelines and evolving regulatory and payment policies.