Clinical features and risk factors of severely and critically ill patients with COVID-19

Table 1 Baseline and clinical characteristics of patients with coronavirus disease 2019

Demographics and clinical characteristics	Total	Moderate	Severe	Critically ill	P value
Male	67/126 (53.2)	24/59 (40.7)	30/49 (61.2)	13/18 (72.2)	0.022
Age (yr)		54.76 ± 1.73	59.22 ± 2.10	65.44 ± 3.17	P (Critically ill vs moderate) = 0.019
Exposure history	28/67 (41.8)	10/19 (52.6)	13/36 (36.1)	5/12 (41.7)	0.498
Time from illness onset to hospital admission (d)		16.00 (11.00-18.00)	7.00 (3.75-11.25)	6.00 (4.00-7.00)	P (Critically ill vs moderate) = 0.000; P (Severe vs moderate) = 0.001
Time from illness onset to laboratory confirmation (d)		10.00 (5.00-13.00)	7.50 (3.75-18.00)	2.00 (0.0 -4.50)	0.176
Comorbidity
All	104/126 (82.5)	51/59 (86.4)	35/49 (71.4)	18/18 (100)	P (Critically ill vs severe) < 0.05
COPD/CB	6/126 (4.8)	1/59 (1.7)	3/49 (6.1)	2/18 (11.1)	0.152
Cerebrovascular disease	3/126 (2.4)	0/59 (0)	1/49 (2.0)	2/18 (11.1)	P (Critically ill vs moderate) < 0.05
Coronary heart disease	7/126 (5.6)	4/59 (6.8)	3/49 (6.1)	0/18 (0.0)	0.325
Chronic liver disease	6/126 (4.8)	0/59 (0.0)	5/49 (10.2)	1/18 (5.6)	P (Severe vs moderate) < 0.05
Hypertension	46/126 (36.5)	21/59 (35.6)	16/49 (32.7)	9/18 (50.0)	0.417
Diabetes	22/126 (17.5)	7/59 (11.9)	10/49 (20.4)	5/18 (27.8)	0.238
Hyperlipidemia	1/126 (0.8)	0/59 (0.0)	1/49 (2.0)	0/18 (0.0)	0.532
Cancer	11/126 (8.7)	2/59 (3.4)	4/49 (8.2)	5/18 (27.8)	P (Critically ill vs moderate) < 0.05
Drug history
Aspirin	2/67 (3.0)	0/19 (0.0)	1/36 (2.8)	1/12 (8.3)	0.406
Beta blockers	2/67 (3.0)	1/19 (5.3)	1/36 (2.8)	0/12 (0.0)	1.000
Insulin	2/67 (3.0)	1/19 (5.3)	0/36 (0)	1/12 (8.3)	0.210
Stains	2/67 (3.0)	0/19 (0.0)	2/36 (5.6)	0/12 (0.0)	0.691
ACEIs	6/126 (4.8)	4/59 (6/8)	2/49 (4.1)	0/18 (0.0)	0.623
ARB	16/126 (12.7)	7/59 (11.9)	9/49 (18.4)	0/18 (0.0)	0.045
Drug treatment before admission
All	108/126 (85.7)	55/59 (93.2)	40/49 (81.6)	13/18 (72.2)	P (Critically ill vs moderate) < 0.05
Antibiotics	33/67 (49.3)	7/19 (36.8)	19/36 (53.7)	7/12 (58.3)	0.418
Traditional Chinese medicine	83/126 (65.9)	49/59 (83.1)	28/49 (57.1)	6/18 (33.3)	P (Critically ill vs moderate) < 0.05; P (Severe vs moderate) < 0.05
Arbidol	70/126 (55.6)	43/59 (72.9)	20/49 (40.8)	7/18 (38.9)	P (Critically ill vs moderate) < 0.05; P (Severe vs moderate) < 0.05
Oseltamivir	28/67 (41.8)	10/19 (52.6)	16/36 (44.4)	2/12 (16/7)	0.126
Lopinavir/ritonavir	2/126 (1.6)	1/59 (1.7)	0/49 (0.0)	1/18 (5.6)	0.266
Fever	98/126 (77.8)	44/59 (46.8)	42/49 (85.7)	12/18 (66.7)	0.175
Maximum body temperature		38.90 (38.00-39.40)	38.70 (38.00-39.00)	39.00 (38.92-39.25)	0.440
Rigor	32/67 (47.8)	7/19 (36.8)	20/36 (55.6)	5/12 (42.7)	0.375
Fatigue	43/67 (64.2)	10/19 (52.6)	24/36 (66.7)	9/12 (75.0)	0.405
Sore throat	25/67 (37.3)	6/19 (31.6)	14/36 (38.9)	5/12 (41.7)	0.816
Running nose	1/67 (1.5)	0/19 (0.0)	1/36 (2.8)	0/12 (0.0)	1.000
Stuffy nose	6/67 (9.0)	1/19 (5.3)	5/36 (13.9)	0/12 (0.0)	0.169
Cough	98/126 (77.8)	46/59 (78.0)	40/49 (81.6)	12/18 (66.7)	0.426
Expectoration	39/67 (58.2)	11/19 (57.9)	22/36 (61.1)	6/12 (50.0)	0.795
White sputum	14/67 (20.9)	1/19 (5.3)	11/36 (30.6)	2/12 (16.7)	0.083
Yellow sputum	5/67 (7.5)	1/19 (5.3)	4/36 (11.1)	0/12 (0.0)	0.571
Blood-stained sputum	15/67 (22.4)	5/19 (26.3)	8/36 (22.2)	2/12 (16.7)	0.817
Shortness of breath	49/126 (38.9)	19/59 (32.2)	22/49 (44.9)	8/18 (44.4)	0.352
Exertional dyspnea	24/67 (35.8)	6/19 (31.6)	14/36 (38.9)	4/12 (33.3)	0.848
Headache	22/67 (32.8)	7/19 (36.8)	11/36 (30.6)	4/12 (33.3)	0.895
Myalgia	29/67 (43.3)	5/19 (26.3)	18/36 (50.0)	6/12 (50.0)	0.211
Abdominal pain	21/67 (31.3)	4/19 (21.1)	13/36 (36.1)	4/12 (33.3)	0.497
Diarrhea	40/126 (31.7)	16/59 (27.1)	20/49 (40.8)	4/18 (22.2)	0.202
Nausea	29/67 (43.3)	7/19 (36.8)	17/36 (47.2)	5/12 (41.7)	0.755
Anorexia	32/67 (47.8)	6/19 (31.6)	20/36 (55.6)	6/12 (50.0)	0.235
Vomiting	22/67 (32.8)	4/19 (21.1)	13/36 (36.1)	5/12 (41.7)	0.392
Conjunctivitis	0/67 (0.0)	0/19 (0.0)	0/36 (0.0)	0/12 (0.0)	-

Data are presented as n/n (%) or mean ± SD or median (interquartile range). P values were calculated by Mann-Whitney U test, χ² test, or Fisher’s exact test, as appropriate.

Table 2 Laboratory findings of patients with coronavirus disease 2019

Laboratory findings	Total	Moderate	Severe	Critically ill	P value
Leukocyte count, × 109/L	6.02 ± 2.07	5.79 ± 0.21	6.09 ± 0.32	6.66 ± 0.71
Total	125/125 (100)	59/125 (47.2)	49/125 (39.2)	17/125 (13.6)	0.26
Lower (< 3.5)	13/125 (10.4)	4/59 (6.8)	6/49 (12.2)	3/17 (17.6)
Normal (3.5-9.5)	104/125 (83.2)	53/59 (89.8)	39/49 (79.6)	12/17 (70.6)
Higher (> 9.5)	8/125 (6.4)	2/59 (3.4)	4/49 (8.2)	2/17 (11.8)
Neutrophil count, × 109/L	3.78 (2.40-5.15)	3.37 (2.40-4.19)	4.05 (2.34-5.17)	5.71 (2.82-7.45)
Total	121/121 (100)	56/121 (46.3)	47/121 (38.8)	18/121 (14.9)	P (Moderate vs critically ill) < 0.05
Lower (< 1.8)	13/121 (10.8)	3/56 (5.4)	7/47 (14.9)	3/18 (16.7)
Normal (1.8-6.3)	91/121 (75.2)	50/56 (89.2)	33/47 (70.2)	8 (44.4)
Higher (> 6.3)	17/121 (14.0)	3/56 (5.4)	7/47 (14.9)	7 (38.9)
Neutrophil ratio	63.70 (53.75-73.80)	57.85 (52.80-57.85)	68.55 (52.53-75.78)	81.05 (72.90-87.25)
Total	124/124 (100)	58/124 (46.8)	48/124 (38.7)	18/124 (14.5)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05; P (Severe vs critically ill) < 0.05
Lower (< 40)	4/124 (3.2)	0/58 (0)	4/48 (8.5)	0/18 (0)
Normal (40-75)	89/124 (71.8)	53/58 (91.4)	31/48 (64.6)	5/18 (27.8)
Higher (> 75)	31/124 (25.0)	5/58 (8.6)	13/48 (27.1)	13/18 (72.2)
Eosinophil count, × 109/L	0.08 (0.03-0.15)	0.13 (0.06-0.20)	0.07 (0.02-0.14)	0.00 (0.00-0.06)
Total	121/121 (100)	56/121 (46.3)	47/121 (38.8)	18/121 (14.9)	P (Moderate vs critically ill) < 0.05; P (Severe vs critically ill) < 0.05
Lower (< 0.02)	25/121 (20.7)	3/56 (5.4)	11/47 (23.4)	11/18 (61.1)
Normal (0.02-0.52)	95/121 (78.5)	52/56 (92.9)	36/47 (76.6)	7/18 (38.9)
Higher (> 0.52)	1/121 (0.8)	1/56 (1.8)	0/56 (0.0)	0/56 (0.0)
Eosinophil ratio,	1.35 (0.40-2.83)	2.20 (1.10-3.40)	1.25 (0.20-2.18)	0 (0-0.65)
Total	122/122 (100)	56/122 (45.9)	48/122 (39.3)	18/122 (14.8)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05; P (Severe vs critically ill) < 0.05
Lower (< 0.4)	29/122 (23.8)	3/56 (5.4)	14/48 (29.2)	12/18 (23.8)
Normal (0.4-8)	91/122 (74.6)	51/56 (91.1)	34/48 (70.8)	6/18 (74.6)
Higher (> 8)	2/122 (1.6)	2/56 (3.6)	0/48 (0)	0/18 (0)
Monocyte count, × 109/L	0.53 (0.40-0.66)	0.55 (0.46-0.66)	0.55 (0.38-0.67)	0.39 (0.20-0.56)
Total	123/123 (100)	57/123 (46.3)	48/123 (39.0)	18/123 (14.7)	0.266
Lower (< 0.1)	1/123 (0.8)	0/57 (0.0)	0/48 (0.0)	1/18 (5.6)
Normal (0.1-0.6)	80/123 (65.0)	37/57 (64.9)	30/48 (62.5)	13/18 (72.2)
Higher (> 0.6)	42/123 (34.1)	20/57 (35.1)	18/48 (37.5)	4/18 (22.2)
Monocyte ratio,	9.05 (7.90-10.33)	9.15 (8.23-11.03)	9.3 (8.03-10.28)	5.90 (3.75-8.80)
Total	122/122 (100)	56/122 (45.9)	48/122 (39.3)	18/122 (14.8)	P (Moderate vs critically ill) < 0.05
Lower (< 3)	3/122 (2.5)	0/56 (0)	1/48 (2.1)	2/18 (11.1)
Normal (3-10)	82/122 (67.2)	35/56 (62.5)	33/48 (68.8)	14/18 (77.8)
Higher (> 10)	37/122 (30.3)	21/56 (37.5)	14/48 (29.2)	2/18 (11.1)
Lymphocyte count, × 109/L	1.25 (0.92-1.88)	1.79 (1.25-2.01)	1.19 (0.90-1.44)	0.70 (0.52-0.87)
Total	121/121 (100)	56/121 (46.3)	47/121 (38.8)	18/121 (14.9)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05; P (Severe vs critically ill) < 0.05
Lower (< 1.1)	44/121 (36.4)	8/56 (14.3)	20/47 (42.6)	16/18 (88.9)
Normal (1.1-3.2)	75/121 (62.0)	47/56 (83.9)	26/47 (55.3)	2/18 (11.1)
Higher (> 3.2)	2/121 (1.7)	1/56 (1.8)	1/47 (2.1)	0/18 (0.0)
Lymphocyte ratio,	24.40 (14.55-32.40)	29.60 (23.20-34.10)	20.15 (13.40-33.28)	12.95 (8.50-20.15)
Total	125/125 (100)	59/125 (47.2)	48/125 (38.4)	18/125 (14.4)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Lower (< 20)	35/125 (28.0)	9/59 (15.3)	23/48 (47.9)	13/18 (72.2)
Normal (20-50)	77/125 (61.6)	50/59 (84.7)	22/48 (45.8)	5/18 (27.8)
Higher (> 50)	3/125 (2.4)	0/59 (0)	3/48 (6.3)	0/18 (0)
Hemoglobin, g/L	127.00 (114.00-136.00)	127.00 (116.00-135.00)	126.00 (114.75-136.75)	123.00 (103.00-136.00)
Total	123/123 (100)	57/123 (47.2)	48/123 (38.4)	18/123 (14.4)	P (Moderate vs critically ill) < 0.05
Lower (< 1151, < 1302)	58/123 (47.2)	21/57 (36.8)	24/48 (50)	13/18 (72.2)
Normal (115-1501, 130-1752)	65/123 (52.8)	36/57 (63.2)	24/48 (50)	5/18 (27.8)
Hematocrit,	36.50 (33.30-39.40)	37.40 (33.75-39.60)	36.5 (33.15-39.95)	34.55 (29.85-38.65)
Total	123/123 (100)	57/123 (46.4)	48/123 (39.0)	18/123 (14.6)	P (moderate vs critically ill) < 0.05
Lower (< 341, < 402)	78/123 (63.4)	29/57 (50.9)	33/48 (68.8)	16/18 (88.9)
Normal (34-451, 40-502)	44/123 (35.8)	27/57 (47.4)	15/48 (31.3)	2/18 (11.1)
Higher (> 451, > 452)	1/123 (0.8)	1/57 (1.8)	0/48 (0)	0/18 (0)
Platelet’s count, × 109/L	260.00 (187.50-342.50)	268.00 (212.50-336.75)	287.00 (193.00-368.00)	157.00 (67.00-230.75)
Total	122/122 (100)	56/122 (45.9)	48/122 (39.3)	18/122 (14.8)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Lower (< 125)	10/122 (8.2)	2/56 (3.6)	2/48 (4.2)	6/18 (33.3)
Normal (125-350)	84/122 (68.8)	41/56 (73.2)	32/48 (66.7)	1118 (61.1)
Higher (> 350)	28/122 (23.0)	13/56 (23.2)	14/48 (29.2)	1/18 (5.6)
Neutrophil to lymphocyte ratio	2.57 (1.57-4.82)	1.99 (1.43-2.81)	3.29 (1.49-5.50)	6.21 (3.62-9.78)
Total	121/121 (100)	55/121 (45.4)	48/121 (39.7)	18/121 (14.9)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Normal (≤ 3.13)	71/121 (58.7)	46/55 (83.6)	21/55 (43.8)	4/55 (22.2)
Higher (> 3.13)	50/121 (41.3)	9/55 (16.4)	27/55 (56.3)	14/55 (77.8)
Alanine aminotransferase, U/L	25.00 (15.00-43.00)	22.00 (16.00-41.00)	28.00 (13.50-45.50)	37.00 (14.00-47.50)
Total	123/123 (100)	57/123 (46.4)	49/123 (39.8)	17/123 (13.8)	0.77
Normal (≤ 331, ≤ 412)	89/123 (73.4)	43/57 (74.4)	34/49 (69.4)	12/17 (70.6)
Higher (> 331, > 412)	34/123 (27.6)	14/57 (24.6)	15/49 (30.6)	5/17 (29.4)
Lactate dehydrogenase, U/L	253.0 (193.25-300.0)	210.0 (186.0-266.5)	262.00 (193.00-300.00)	341.00 (286.75-497.00)
Total	120/120 (100)	55/120 (45.8)	57/120 (47.5)	18/120 (14.7)	P (Moderate vs critically ill) < 0.05
Lower (< 135)	5/120 (4.2)	4/55 (7.3)	1/57 (2.1)	0/18 (0)
Normal (135-2141, 135-2252)	44/120 (36.7)	24/55 (43.6)	18/57 (38.3)	2/18 (11.1)
Higher (>2141,>2252)	71/120 (59.2)	27/55 (49.1)	28/57 (59.6)	16/18 (88.9)
Aspartate aminotransferase, U/L	24.00 (17.00-37.00)	22.00 (17.00-29.00)	22.00 (17.00-37.00)	42.00 (21.00-68.50)
Total	123/123 (100)	57/123 (46.4)	49/123 (39.8)	17/123 (13.8)	P (Moderate vs critically ill) < 0.05
Normal (≤ 321, ≤ 402)	94/123 (76.4)	48/57 (84.2)	39/49 (79.6)	7/17 (41.2)
Higher (> 321, > 402)	29/123 (23.6)	9/57 (15.8)	10/49 (20.4)	10/17 (58.8)
Serum amylase, U/L	69.33 ± 2.65	66.51 ± 3.55	71.59 ± 5.17	71.92 ± 4.92
Total	77/77 (100)	35/77 (45.4)	29/77 (39.7)	13/77 (14.9)	0.13
Lower (< 28)	1/77 (1.3)	1/35 (2.9)	0/29 (0)	0/13 (0)
Normal (28-100)	66/77 (85.7)	32/35 (91.4)	22/29 (75.9)	12/13 (92.3)
Higher (> 100)	10/77 (13.0)	2/35 (5.7)	7/29 (24.1)	1/13 (7.7)
Total bilirubin, μmol/L	8.00 (5.90-12.00)	7.40 (4.30-10.60)	8.65 (5.98-12.43)	10.45 (7.98-18.13)
Total	121/121 (100)	55/121 (45.4)	48/121 (39.7)	18/121 (14.9)	0.18
Normal (≤ 211, ≤ 262)	116/121 (95.9)	54/55 (98.2)	46/48 (95.8)	16/18 (88.9)
Higher (> 211, > 262)	5/121 (4.1)	1/55 (1.8)	2/48 (4.2)	2/18 (11.1)
Albumin, g/L	36.19 ± 4.87	39.25 ± 0.51	34.44 ± 0.56	31.49 ± 1.03
Total	121/121 (100)	55/121 (45.4)	48/121 (39.7)	18/121 (14.9)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Lower (< 35)	46/121 (38.0)	7/55 (12.7)	27/48 (56.3)	12/18 (66.7)
Normal (35-52)	75/121 (62.0)	48/55 (87.3)	21/48 (43.8)	6/18 (33.3)
Creatinine, μmol/L	69.00 (59.00-78.00)	67.00 (58.00-80.00)	69.00 (60.00-76.00)	73.00 (54.75-87.50)
Total	121/121 (100)	55/121 (45.4)	48/121 (39.7)	18/121 (14.9)	P (Moderate vs severe) < 0.05; P (Severe vs critically ill) < 0.05
Lower (< 451, < 582)	13/121 (10.7)	2/55 (3.6)	6/48 (12.5)	5/18 (27.8)
Normal (45-841, 59-1042)	101/121 (83.5)	51/55 (92.7)	41/48 (85.4)	9/18 (50)
Higher (> 841, > 1042)	7/121 (5.8)	2/55 (3.6)	1/48 (2.1)	4/18 (22.2)
C-reactive protein, mg/L	6.55 (1.60-38.50)	2.30 (1.20-6.70)	12.40 (2.68-48.58)	91.00 (37.3-131.25)
Total	122/122 (100)	57/122 (46.7)	48/122 (39.4)	17/122 (13.9)	P (Moderate vs severe) < 0.05
Normal (≤ 1)	15/122 (12.3)	12/57 (21.1)	2/48 (4.2)	1/17 (5.9)
Higher (> 1)	107/122 (87.7)	45/57 (78.9)	46/48 (95.8)	16/17 (94.1)
Creatine kinase, U/L	46.00 (33.50-66.50)	41.00 (34.50-58.50)	52.00 (33.00-77.00)	55.00 (40.00-148.00)
Total	101/101 (100)	49/101 (48.5)	37/101 (36.6)	15/101 (14.9)	0.09
Normal (≤ 170)	94/101 (93.1)	46/49 (93.9)	36/37 (97.3)	12/15 (80)
Higher (> 170)	7/101 (6.9)	3/49 (6.1)	1/37 (2.7)	3/15 (20)
Procalcitonin3, ng/mL
Total	91/91 (100)	37/91 (40.7)	37/91 (40.7)	17/91 (18.6)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Lower (< 0.02)	6/91 (6.6)	0/37 (0)	5/37 (13.5)	1/17 (5.9)
Normal (0.02-0.05)	44/91 (48.4)	25/37 (67.6)	17/37 (45.9)	2/17 (11.8)
Higher (> 0.05)	41/91 (45.0)	12/37 (32.4)	15/37 (40.5)	14/17 (82.4)
Potassium, mmol/L	4.24 (3.96-4.64)	4.24 (3.97-4.40)	4.30 (3.92-4.75)	4.15 (3.85-4.59)
Total	64/64 (100)	16/64 (25.0)	36/64 (56.3)	12/64 (18.7)	0.27
Lower (< 3.5)	1/64 (1.6)	0/16 (0)	0/36 (0)	1/12 (8.3)
Normal (3.5-5.1)	58/64 (90.6)	14/16 (87.5)	34/36 (94.4)	10/12 (83.3)
Higher (> 5.1)	5/64 (7.8)	2/16 (12.5)	2/36 (5.6)	1/12 (8.3)
Corrected calcium, mmol/L	2.41 ± 0.10	2.41 ± 0.02	2.40 ± 0.02	2.45 ± 0.04
Total (< 2.15)	63/63 (100)	16/63 (25.4)	35/63 (55.6)	12/63 (19.0)	1.00
Normal (2.15-2.57)	59/63 (93.7)	15/16 (93.8)	33/35 (94.3)	11/12 (91.7)
Higher (> 2.57)	4/63 (6.3)	1/26 (6.3)	2/35 (5.7)	1/12 (8.3)
Calcium, mmol/L	2.16 ± 0.11	2.20 ± 0.01	2.14 ± 0.01	2.10 ± 0.03
Total	120/120 (100)	54/120 (45.0)	48/120 (40.0)	18/120 (15.0)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Lower (< 2.151, < 2.202)	68/120 (56.7)	17/54 (31.5)	35/48 (72.9)	16/18 (88.9)
Normal (2.15-2.51, 2.2-2.552)	52/120 (43.3)	37/54 (68.5)	13/48 (27.1)	2/18 (11.1)
Thrombin time, s	16.25 (15.28-16.93)	15.15 (14.53-16.18)	16.40 (15.55-17.20)	16.90 (14.73-19.55)
Total	66/66 (100)	18/66 (27.3)	36/66 (54.5)	12/66 (18.2)	P (Moderate vs critically ill) < 0.05
Lower (< 14)	1/66 (1.5)	0/18 (0)	0/36 (0)	1//36 (8.3)
Normal (14-19)	57/66 (86.4)	18/18 (100)	32/36 (88.9)	7/36 (58.3)
Higher (> 19)	8/66 (12.1)	0/18 (0)	4/36 (11.1)	4/36 (33.3)
Prothrombin time, s	13.65 (13.20-14.23)	13.25 (13.18-13.60)	13.95 (13.45-14.28)	14.00 (13.03-15.28)
Total	66/66 (100)	18/66 (27.3)	36/66 (54.5)	12/66 (18.2)	P (Moderate vs critically ill) < 0.05
Normal (11.5-14.5)	55/66 (83.3)	18/18 (100)	30/36 (83.3)	7/12 (58.3)
Higher (> 14.5)	11/66 (16.7)	0/18 (0)	6/36 (16.7)	5/12 (41.7)
Prothrombin activity	94.00 (86.00-100.00)	99.50 (95.50-102.25)	90.50 (86.25-96.75)	88.50 (75.00-105.00)
Total	66/66 (100)	18/66 (27.3)	36/66 (54.5)	12/66 (18.2)	P (Moderate vs critically ill) < 0.05
Lower (< 75)	7/66 (10.6)	0/18 (0)	4/36 (11.1)	3/12 (25)
Normal (75-125)	58/66 (87.9)	18/18 (100)	32/36 (88.9)	8/12 (66.7)
Higher (> 125)	1/66 (1.5)	0/18 (0)	0/36 (0)	1/12 (8.3)
Fibrinogen, g/L	4.46 ± 0.18	3.72 ± 0.22	4.75 ± 0.25	4.68 ± 0.55
Total	66/66 (100)	18/66 (27.3)	36/66 (54.5)	12/66 (18.2)	P (Moderate vs critically ill) < 0.05
Lower (< 2)	3/66 (4.5)	0/18 (0)	1/36 (2.8)	2/12 (16.7)
Normal (2-4)	24/66 (36.4)	11/18 (61.1)	12/36 (33.3)	1/12 (8.3)
Higher (> 4)	39/66 (59.1)	7/18 (38.9)	23/36 (63.9)	9/12 (75)
D-dimer3, μg/mL
Total	124/124 (100)	57/124 (46.0)	49/124 (39.5)	18/124 (14.5)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Normal (< 0.5)	44/124 (35.5)	34/57 (59.6)	10/49 (20.4)	0/18 (0)
Higher (≥ 0.5)	80/124 (64.5)	23/57 (40.4)	39/49 (79.6)	18/18 (100)
High-sensitivity cardiac troponin3, pg/mL
Total	123/123 (100)	56/123 (46.4)	49/123 (39.0)	18/123 (14.6)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05
Normal (≤15.61, ≤34.22)	117/123 (95.1)	54/56 (96.4)	49/49 (100)	14/18 (77.8)
Higher (>15.61, >34.22)	6/123 (4.9)	2/56 (3.6)	0/49 (0)	4/18 (22.2)
Amino-terminal pro-brainnatriuretic peptide3, pg/mL
Total	123/123 (100)	57/123 (45.5)	49/123 (39.9)	18/123 (14.6)	P (Moderate vs severe) < 0.05; P (Moderate vs critically ill) < 0.05; P (Severe vs critically ill) < 0.05
Normal (< 2851, < 4862)	83/123 (67.5)	50/57 (87.7)	29/49 (60.4)	4/18 (22.2)
Higher (≥ 2851, ≥ 4862)	40/123 (32.5)	7/57 (12.3)	19/49 (39.6)	14/18 (77.8)
Ferritin, μg/L	468.25 (292.18-1022.08)	9.80 (4.30-18.68)	269.05 (169.60-407.23)	601.60 (383.5-1195.90)
Total	62/62 (100)	18/62 (29.0)	31/62 (50.0)	13/62 (21.0)	0.08
Lower (< 151, < 302)	2/62 (3.2)	1/18 (5.6)	1/31 (3.2)	0/13 (0)
Normal (15-1501, 30-4002)	15/62 (24.2)	8/18 (44.4)	6/31 (19.4)	1/13 (7.7)
Higher (> 1501, > 4002)	45/62 (72.6)	9/18 (50)	24/31 (77.4)	12/13 (92.3)

¹The normal and abnormal range applied to female patients.

²The normal and abnormal range applied to male patients.

³Comparisons between groups were not completed because the laboratory item was grade variables.

Data are presented as n/n (%) or mean ± SD or median (interquartile range). The level of each laboratory finding was divided as normal and abnormal levels (lower than normal or higher than normal) according to the standard normal physiological range of our research centers. Average levels of each group were described by mean ± SD or median (interquartile range). Numbers and proportions of patients with different levels of each laboratory item were presented above.

Table 3 Logistic regression results of potential risk factors for severity of coronavirus disease 2019

	Wald χ2	P value	OR	95%CI
				Upper bound	Lower bound
Intercept (Moderate)	1.800	0.180	9.816	-	-
Intercept (Severe)	1.122	0.289	0.179	-	-
Age	5.477	0.019	1.055	1.009	1.104
High-sensitivity cardiac troponin I
Normal (≤ 15.61, ≤ 34.22)
Higher (> 15.61, > 34.22)	4.094	0.043	4.019	1.045	15.467
Neutrophil to lymphocyte ratio
Higher (> 3.13)	5.477	0.042	10.126	1.088	94.247
Normal (≤ 3.13)

¹The normal and abnormal range applied to female patients.

²The normal and abnormal range applied to male patients.

Ordinal logistic regression model was adopted in JMP15.0 software to explore the risk factors associated with severity of coronavirus disease 2019 patients. Step-by-step regression method (P for inclusion = 0.05, P for exclusion = 0.05) was applied and 3 variables were included in the final model. Results showed that total model test χ² = 17.380, P < 0.001, which means at least one β in the equation did not equal to 0 and this model was preceded to constant 1. Good-to-fitness test showed χ² = 59.137, P = 0.968 > 0.05, which means this model fit well. OR: Odds ratio.