Preadmission usage of metformin and mortality in COVID-19 patients including the post-discharge period.

Background: The effect of preadmission metformin usage (PMU) on the mortality of coronavirus disease-2019 (COVID-19) patients with diabetes is conflicting. Most studies have focused on in-hospital mortality; however, mortality after discharge also increases in COVID-19 patients.

Aims: Examining the effect of PMU on all-cause mortality, including the post-discharge period.