Healthcare Cost Trends in New Users of SGLT ‐2i, DPP ‐4i and GLP ‐1 RA for Type 2 Diabetes: An Observational Longitudinal Study

AIMS: To analyse the healthcare cost trajectories following the initiation of glucagon-like peptide-1 receptor agonist (GLP-1 RA), sodium-glucose cotransporter-2 inhibitor (SGLT-2i) or dipeptidyl peptidase-4 inhibitor (DPP-4i) therapy in patients with type 2 diabetes. MATERIALS AND METHODS: We conducted a difference-in-difference study using member-level claims data from a national pharmacy benefit manager. Treatment-naïve patients were categorised into three groups based on the drug they initiated first. The first fill date in 2020 or 2021 was the index date, with a one-year look-back period and 2 years of follow-up. Propensity score weighting balanced the groups. We used generalised estimating equations to analyse year-over-year changes in per patient per month (PPPM) costs for medical, pharmacy and total cost of care expenditures. RESULTS: Changes in medical costs were not statistically different across drug groups in years 1 and 2. In contrast, the increase in pharmacy costs in the first year for GLP-1 RA was significantly higher than the other two drugs. Driven primarily by pharmacy costs, total cost of care trajectories showed similar between-drug differences. CONCLUSION: Patients with type 2 diabetes initiating on a GLP-1 RA show significantly higher pharmacy cost patterns as compared to the DPP-4i and SGLT-2i groups; this higher pharmacy cost is not offset by reduced medical cost during the same period. Payers and providers should consider these cost patterns in both coverage and treatment decisions.