Table 1.

Characteristics of the selected studies.

				Mild disease or survivor				Severe disease or non-survivor
First Author,	Study		NOS	n	Age	Gender	CK-MB	n	Age	Gender	CK-MB
Country [reference]	design	Endpoint	(stars)		(Years)	(M/F)	U/L		(Years)	(M/F)	U/L
							(Mean ±SD)				(Mean ±SD)
Aladağ N et al.,	R	Survival status	7	35	68	22/13	29 ​± ​23	15	68	6/9	33 ​± ​25
Turkey [34]
Cao L et al.,	R	Survival status	7	78	68	33/45	0.8 ​± ​0.4a	22	81	12/10	4.9 ​± ​5.4a
China [35]
Chen FF et al.,	R	Survival status	7	577	63	297/280	1.1 ​± ​0.6a	104	73	65/39	3.7 ​± ​3.1a
China [36]
Chen J et al.,	R	Mechanical ventilation	7	68	67	38/30	36 ​± ​77	30	68	18/12	10 ​± ​13
China [37]
Deng M et al.,	R	Disease severity	7	53	35	24/29	10 ​± ​5	12	33	12/0	10 ​± ​13
China [38]
Deng P et al.,	R	Survival status	7	212	63	97/115	1.1 ​± ​0.6a	52	75	33/19	2.0 ​± ​0.5a
China [39]
Dong X et al.,	R	Survival status	7	65	54	30/35	24 ​± ​15	54	70	38/16	39 ​± ​29
China [40]
Du RH et al.,	R	ICU admission	5	58	68	38/20	3.7 ​± ​4.1a	51	79	36/15	5.4 ​± ​6.7a
China [41]
Feng X et al.,	P	Composite endpointb	7	94	63	58/36	18 ​± ​6	20	69	13/7	21 ​± ​14
China [42]
Feng Y et al.,	R	Disease severity	5	352	51	190/162	13 ​± ​4	124	60	81/43	16 ​± ​7
China [43]
Gao S et al.,	R	Survival status	5	175	70	79/96	9 ​± ​4	35	74	22/13	13 ​± ​8
China [44]
Gong J et al.,	R	Disease severity	5	161	45	72/89	12 ​± ​5	28	64	16/12	16 ​± ​17
China [45]
Guo H et al.,	R	Survival status	7	28	59	NR	6 ​± ​21a	46	72	NR	11 ​± ​49a
China [46]
Guo J et al.,	R	Survival status	6	43	60	22/21	11 ​± ​4	31	68	21/10	18 ​± ​7
China [47]
Han H et al.,	R	Disease severity	5	198	60	71/127	1.0 ​± ​0.6a	75	59	26/49	1.3 ​± ​1.1a
China [48]
He B et al.,	NR	Disease severity	5	32	42	15/17	0.6 ​± ​0.2a	21	57	13/8	1.6 ​± ​1.2a
China [49]
Hu J et al.,	R	Disease severity	7	130	63	58/72	13 ​± ​17	52	64	42/10	42 ​± ​93
China [50]
Hu X et al.,	R	Disease severity	7	175	41	80/95	9.2 ​± ​4.5	38	53	22/16	8.9 ​± ​4.4
China [51]
Jang JG et al.,	R	Disease severity	7	87	68	34/53	1.9 ​± ​1.8a	23	54	14/9	5.3 ​± ​4.1a
Korea [52]
Ji L et al.,	P	Composite endpointc	7	243	52	121/122	0.4 ​± ​0.2	37	71	20/17	14 ​± ​20
China [53]
Li N et al.,	R	Disease severity	7	103	61	48/55	0.8 ​± ​0.7a	35	67	23/12	2.7 ​± ​2.9a
China [54]
Li Y et al.,	R	Survival status	7	64	54	30/34	11.7 ​± ​3.7	37	72	23/14	22.3 ​± ​16.3
China [55]
Liu SL et al.,	R	Disease severity	5	194	43	91/103	9.3 ​± ​3.4	31	64	17/14	13.7 ​± ​7.4
China [56]
McRae MP et al.,	R	Survival status	5	117	63	52/65	5.5 ​± ​7.5a	43	73	30/13	8.6 ​± ​11.8a
USA [57]
Mertoglu C et al.,	R	ICU admission	7	532	48	306/226	16.4 ​± ​5.5	23	59	13/10	49 ​± ​52
Turkey [58]
Qin W et al.,	R	Survival status	7	239	63	113/126	0.9 ​± ​0.4a	23	69	10/13	2.0 ​± ​1.3a
China [59]
Tao Z et al.,	R	Disease severity	7	202	54	72/130	4.1 ​± ​5.5a	20	65	8/12	2.5 ​± ​2.2a
China [60]
Tuo H et al.,	R	Survival status	5	96	51	38/58	0.8 ​± ​0.6a	52	69	29/23	2.8 ​± ​2.3a
China [61]
Wang B et al.,	R	Survival status	7	54	62	40/14	24 ​± ​23	50	72	40/10	29 ​± ​22
China [62]
Wang C et al.,	R	Disease severity	6	35	38	17/18	16 ​± ​13	10	43	6/4	20 ​± ​7
China [63]
Wang D et al.,	R	Disease severity	5	72	44	29/43	13 ​± ​5	71	65	44/27	14 ​± ​8
China [64]
Wang F et al.,	R	Disease progression	7	253	41	109/144	0.6 ​± ​0.6a	70	60	45/25	0.7 ​± ​0.7a
China [65]
Wang G et al.,	NR	Disease severity	7	193	42	95/98	60 ​± ​55	16	54	10/6	8.4 ​± ​4.6
China [66]
Wang JH et al.,	R	Survival status	7	1074	61	502/572	0.8 ​± ​0.4a	61	74	43/18	2.5 ​± ​2.7a
China [67]
Wang K et al.,	P	Survival status	7	277	46	129/148	14 ​± ​4	19	66	11/8	21 ​± ​8
China [68]
Wang Z et al.,	R	Survival status	7	100	58	44/56	1.0 ​± ​0.5	56	72	32/24	6.4 ​± ​8.6
China [69]
Wu C et al.,	R	Presence of ARDS	6	117	48	68/49	15.3 ​± ​5.2	84	59	60/24	16.8 ​± ​5.6
China [70]
Xie J et al.,	NR	Disease progression	6	75	51	45/30	19.3 ​± ​5.9	29	66	18/11	22 ​± ​7.4
China [71]
Xie Y et al.,	R	Disease severity	5	38	61	14/24	0.6 ​± ​0.4	24	72	13/11	0.8 ​± ​0.5
China [72]
Xu B et al.,	R	Survival status	5	117	56	59/58	14 ​± ​6	28	73	17/11	21 ​± ​10
China [73]
Yang A et al.,	R	Disease severity	5	99	49	49/50	11 ​± ​10	15	60	7/8	12.1 ​± ​7.2
China [74]
Yang C et al.,	R	Survival status	7	145	57	77/68	13 ​± ​6	58	67	38/20	19 ​± ​7
Chin [75]
Yang J et al.,	R	Survival status	5	332	55	170/162	1.2 ​± ​1.0a	25	75	15/10	7 ​± ​6.7a
China [14]
Yao Q et al.,	R	Survival status	6	96	51	36/60	16 ​± ​5	12	65	7/5	23 ​± ​10
China [76]
Yu Z et al.,	R	Survival status	7	123	80	46/77	7.3 ​± ​3.7	18	84	11/7	8.8 ​± ​6.1
China [77]
Zeng Z et al.,	R	ICU admission	7	406	43	206/200	10.6 ​± ​5.5	55	60	33/22	12 ​± ​6.4
China [78]
Zhang C et al.,	R	Disease severity	7	56	44	24/32	0.5 ​± ​0.7	24	65	9/15	1.1 ​± ​1.2
China [79]
Zhang G et al.,	R	Disease severity	5	166	51	73/93	12.3 ​± ​3.7	55	62	35/20	22.3 ​± ​15.6
China [80]
Zhang JJ et al.,	R	Survival status	7	240	53	119/121	1.2 ​± ​1.0	49	69	25/14	2.3 ​± ​1.9
China [81]
Zhang Q et al.,	R	Disease severity	7	47	61	18/29	9.3 ​± ​3.0	27	72	18/9	16.3 ​± ​8.9
China [82]
Zhang XB et al.,	R	Survival status	7	410	53	219/191	7.1 ​± ​7.6	22	66	11/11	19.4 ​± ​19.6
China [83]
Zhao Y et al.,	R	Disease severity	7	336	43	145/191	0.8 ​± ​0.4	81	56	53/28	1.1 ​± ​0.4
China [84]
Zhou C et al.,	R	Disease severity	7	95	35	38/57	6.9 ​± ​3.7	28	40	17/11	8.0 ​± ​2.0
China [85]
Zhou J et al.,	NR	ICU admission	5	156	40	75/81	11.1 ​± ​6.2	45	57	27/18	9.3 ​± ​4.7
China [86]
Zhu Y et al.,	R	Survival status	5	73	73	39/34	1.8 ​± ​1.3	29	62	19/20	7.2 ​± ​8.7
China [87]

Abbreviations: ICU, intensive care unit; NOS, Newcastle-Ottawa quality assessment scale for case–control studies; NR, Not Reported; P, prospective; R, retrospective; ARDS, acute respiratory distress syndrome.

^a-ng/mL or μg/L.

^b-survival status on discharge, disease severity, and mechanical ventilation.

^c-survival status on discharge, presence of ARDS.