Table 1.
Retrospective cohort studies of effect of metformin on mortality in hospitalized patients with COVID-19.
| Author | Country | Number of patients with T2DM and COVID-19/patients on metformin | Odds ratio for mortality (95% CI) | P value (metformin vs. non-metformin groups) | Remarks |
|---|---|---|---|---|---|
| Crouse et al. [35] | USA | 220/76 | 0.33 (0.13, 0.84) | 0.0210 | Association between metformin and reduced mortality significant even after excluding patients with chronic kidney disease and heart failure |
| Cariou et al. [36] | France | 1317/745 | 0.80 (0.45, 1.43) | 0.4532 | No association between metformin and mortality |
| Bramante et al. [37] | USA | 6035/2316 | Women: 0.790 ( 0.637, 0.978); Overall: 0.808 (0.651, 1.003) |
Women 0.013; Overall: NS |
Association between metformin and reduced mortality significant only in women |
| Luo et al. [38] | China | 283/104 | 0.23 (0.07, 0.77) | 0.02 | Effect of metformin on reduction in mortality observed even though glycemic control was similar in both groups |