Table 1.

Characteristics of the observational studies comparing death rates in metformin users vs non-users among patients with type 2 diabetes hospitalized for COVID-19.

No.	Author	Subjects	Mortality (Metformin vs non Metformin) (n)	Odds Ratio M-H (Mantel–Haenszel test), Fixed, 95% CI
1	Abu-Jamous et al.	411	4 vs 94	0.19 (0.05–0.70)
2	Cariou et al.	1317	N/A	0.59 (0.42–0.84)
3	Bramante et al.	6256	394 (17.8%) vs 791 (21.3%)	OR 0.802 (0.701, 0.917)
4	Chen et al.	120	4 (9.30%) vs 15 (19.48%)	N/A
5	Crouse et al.	239	8 (19%) vs 34 (81%)	OR 0.38 (0.17, 0.87) p = 0.0221
6	Kim et al.	235	N/A	0.36 (0.10–1.23) p = 0.10
7	Luo et al.	283; 104 vs 179	3 (2.9%) vs 22 (12.3%)	4.36 ((1.22–15.59) p = 0.02
8	Philipose et al.	159	45 (22.6)	1.39 (0.84–2.16)
9	Cheng et al.	1213; 678 vs 535	N/A	1.65 (0.71,3.86) p = 0.27
10	Khunti et al.	1,800,005	Mortality rate per 1000 person (9.9 vs 12.9)	0.77 (0.73–0.81)