Cost Effectiveness (CE) Evidence Overview for Metformin and SGLT2is in Type 2 Diabetes (T2D) Patients With Cardiorenal Risk: A Targeted Literature Review

OBJECTIVES: International guidelines started to change the paradigm of T2D treatment away from a glucocentric approach. Thus, SGLT2is are now recommended as 1^st-line treatment in patients with cardiorenal risks. This research explores the level of published evidence and criteria used to support the CE of metformin and SGLT2is in T2D.

METHODS: We systematically searched Medline for eligible publications from January 2019 to April 2024. A multistage screening process was carried out with duplicate removal, abstract and full-text screening to confirm eligibility. Two reviewers independently screened the eligible articles and assessed reporting quality.

RESULTS: Seventy studies were included in the final review, with a global geographical distribution across North America (20), Europe (17), APAC/MENA (17), and LATAM (3). The inclusion criteria for cardiorenal comorbidities varied between studies, with some including established or at risk patients. For example, of the 10 studies claiming CE for SGLT2is in T2D patients with cardiovascular disease (CVD), nine focused on patients with established CVD and one on patients at high risk of CVD. No direct head-to-head studies for SGLT2is vs metformin were identified. No studies were identified that claimed that SGLT2is are CE vs metformin in T2D patients where adequate control could be reached with metformin alone. In over a third of studies (27), SGLT2is were assessed either as an add-on therapy to SoC, metformin or DDP-4is, or CE was assessed directly against second-line treatments such as GLP-1s or DDP-4is. With regards to the treatment of prediabetes, CE was only assessed for metformin (5 studies) and no other therapeutic classes.

CONCLUSIONS: The results suggest that widespread implementation of SGLT2is for T2D patients without comorbidities is not an evidence-based strategy. Furthermore, the majority of CE evidence supports the first-line use of metformin in T2D patients either until glycemic control is not achievable or comorbidities develop.