The length of hospital stay in COVID-19 patients using pre-hospital metformin at a Saudi tertiary hospital: a retrospective cohort study

Among hospitalized patients with type 2 diabetes and COVID-19, metformin use was associated with shorter hospital stays and a higher discharge rate. However, given the retrospective, single-center design, potential survivor bias, and residual confounding, these findings should be interpreted cautiously. Prospective multicenter studies using competing-risk approaches and incorporating mortality outcomes are recommended.