DPP4 and diabetes mellitus: In our cohort, we included patients with newly diagnosed diabetes in 2009–2010, when the Taiwan NHI began to reimburse the cost of DPP-4 inhibitors (2009, 2011, 2011, 2012, and 2015 for sitagliptin, saxagliptin, vildagliptin, linagliptin, and alogliptin, respectively), that accessed the treatment concurrently.