OBJECTIVES : Treatment of type 2 diabetes with the new drug classes sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 (GLP-1) agonists has been associated with lower all-cause mortality, while dipeptidyl peptidase 4 (DPP-4) inhibitors have not. This superior effectiveness has prompted medication switching in recent years, contributing to rising diabetes treatment costs. In this study, we sought to determine the effects of switching from a DPP-4 to an SGLT2 or GLP-1 on healthcare utilization and total costs of care.

METHODS : We studied beneficiaries with type 2 diabetes who switched from a DPP-4 to an SGLT2 or GLP-1 in 2016 using combined medical/pharmaceutical claims from a large pharmacy benefits manager. We compared changes in 2017 utilization (using negative binomial regression) and costs (using generalized linear models) among non-switchers, those who switched to an SGLT2, and those who switched to a GLP-1. We accounted for differences between groups using propensity score matching.

RESULTS : Of 11,602 total DPP-4 users, 252 (2.2%) and 191 (1.6%) switched to a GLP-1 or SGLT2, respectively. Our propensity-matched GLP-1 cohort included 1,512 non-switchers and 252 switchers, while our SGLT2 cohort included 1,146 non-switchers and 191 switchers. Switchers to SGLT2s and GLP-1s each had significantly lower incidence of all-cause hospitalizations compared to non-switchers (62% reduction, p=0.013 and 42% reduction, p=0.036, respectively), but no difference in ER visits. We observed trends towards decreased medical costs and increased pharmacy costs (which reached significance for GLP-1 switchers, $4397.91/member/year, p<0.001), resulting in net increases in total costs of care among switchers to both SGLT2s and GLP-1s.

CONCLUSIONS : While GLP-1s and SGLT2s are associated with fewer hospitalizations, their high costs may outweigh medical savings associated with reduced utilization. As newer diabetes guidelines steer specific populations with diabetes to these drug classes, it is important to optimize drug pricing to realize the value of these innovative treatments.