DPP4 and type 2 diabetes mellitus: The study included three 1:1 propensity score–matched cohorts, each stratified by three frailty strata (non-frail, pre-frail, and frail), using data from the Medicare beneficiaries (2013–2019) including patients with type 2 diabetes who initiated SGLT-2 inhibitors, GLP-1RA, or dipeptidyl peptidase-4 (DPP-4) inhibitors.