Lactic Acidosis, Metformin Use, and Dose-Response Association—Reply

In Reply We used the term lactic acidosis in the title of our study¹ to be consistent with previous literature and to facilitate study identification.² However, our study¹ does not use lactate concentration to define acidosis events. In addition, our study is observational, and the ability to infer causality—even with techniques such as propensity score matching and active comparator analyses—is limited.