Medicaid Expansion and Utilization of Antihyperglycemic Therapies
Methods: We employed a difference-in-difference design to analyze the association of Medicaid expansion on prescription of non-insulin antihyperglycemic therapies. We used 2012-2017 National & State Medicaid data to compare prescription claims and costs between states that did (n=25) and did not expand (n=26) Medicaid by January 2014.
Results: Following Medicaid expansion in 2014, average non-insulin antihyperglycemic therapies per state/1,000 enrollees increased by 4.2%/quarter in expansion states and 1.6%/quarter in non-expansion states. For SGLT2i and GLP-1RA, quarterly growth rates per-1,000 enrollees were 125.3% and 20.7% for expansion states and 87.6% and 16.0% for non-expansion states, respectively. Expansion states had faster utilization and total spending growth in SGLT2i and GLP-1RA than non-expansion states. Difference-in-difference estimates for change in volume of prescriptions after Medicaid expansion between expansion vs. non-expansion states was 1.68 (1.09 to 2.26;P<0.001) for all non-insulin therapies, 0.125 (-0.003 to 0.25;P=0.056) for SGLT2i, and 0.12 (0.055 to 0.18;P<0.001) for GLP-1RA.
Conclusion: Use of non-insulin antihyperglycemic therapies, including SGLT2i and GLP-1RA, increased among low-income adults in both Medicaid expansion and non-expansion states, with a significantly greater increase in overall use and in GLP-1RA use in expansion states. Future evaluation of the population-level health impact of expanded access to these therapies is needed.