Table 3.

Description of studies reporting the association between insulin treatment and the severe/critical complications or in-hospital admission of COVID-19.

No.	Study	Sample size	Complications	Period of insulin treatment	Type of diabetes	Control groups	or	ci1	ci2
1	Bo Yu (14)	689	ICU admission	after admission	T2DM	with or without antidiabetic drugs	11.47	3.4	38.66
2	Bo Yu (14)	689	Invasive mechanical ventilation	after admission	T2DM	with or without antidiabetic drugs	6.73	3.39	13.37
3	Yuchen Chen (16)	904	Poor prognosis	before admission	Diabetes	with or without antidiabetic drugs	3.58	1.37	9.35
4	Luis M. Pérez (10)	2666	ICU admission;	after admission	T2DM	antidiabetic drugs	1.32	1.02	1.71
5	Huadong Yan (23)	717	severity	before admission	T2DM	antidiabetic drugs	2.71	1.6	5.5
6	Hussein Nafakhi (26)	67	extensive lung injury	before admission	Diabetes	antidiabetic drugs	0.4	0.3	5
7	Hussein Nafakhi (26)	67	Partial recovery with persistent symptoms	before admission	Diabetes	antidiabetic drugs	0.3	0.2	4
8	Ting Guo (29)	19	ICU admission	before admission	Diabetes	without antidiabetic drugs	115	4.115	3213.5
No.	Study	Sample size	Complications	Period of insulin treatment	Type of diabetes	Control groups	or	ci1	ci2
1	Luis M. Pérez (10)	2666	In-hospital admission	after admission	T2DM	antidiabetic drugs	1.23	0.95	1.6
2	Ayman A (24)	806	In-hospital admission	before admission	T2DM	antidiabetic drugs	1.46	1.03	2.07
3	Achille Cernigliaro (25)	172	In-hospital admission	before admission	Diabetes	antidiabetic drugs	2.13	1.01	4.49
4	Adèle Lasbleiz (27)	2168	In-hospital admission	before admission	Diabetes	antidiabetic drugs	3.8	1.9	8.1
5	Grenye O’Malley (28)	113	In-hospital admission	after admission	T1DM	without antidiabetic drugs	0.137	0.053	0.352