Study		Exclusion reasons	Remarks	Reference(s)
Ahn, 2020	-			Ahn J. Korean Med. Sci. 2020; 35:e149 10.3346/jkms.2020.35.e149
Shen, 2020	-			Shen C JAMA 2020 Mar 27;323(16):1582-1589. 10.1001/jama.2020.4783
Zhang, 2020	-	no control group		Zhang Chest 2020; : 10.1016/j.chest.2020.03.039
Zhang, 2020	-	no control group		Zhang L Aging (Albany NY) 2020 Apr 22;12(8):6536-6542. 10.18632/aging.103102
Ye, 2020	-	no control group		Ye J. Med. Virol. 2020; : 10.1002/jmv.25882