Kwon S, Kim YC, Park JY, et al. - Among 10,426 patients with type 2 diabetic kidney disease (DKD), researchers performed a retrospective observational cohort study to test the safety and effectiveness of metformin. According to the multivariate Cox analysis, all-cause mortality and incident ESRD were lower in the metformin group. The authors discovered that metformin usage in advanced chronic kidney disease (CKD) patients, particularly those with CKD 3B, reduced the risk of all-cause mortality and incident ESRD. Furthermore, metformin did not raise the risk of lactic acidosis. Considering the remaining biases even after PSM, however, more randomized controlled trials are required to change real-world practice.