Table 1 Clinical characteristics of viral pneumonia between immunocompetent and immunocompromised group

Sex, female, n (%)

290 (36.0)

127 (34.3)

163 (37.4)

0.367

Age, median (IQR)

62.0 (49.0–71.0)

60.0 (49.0–68.0)

63.0 (49.3–75.0)

0.003

 Fever

608 (75.4)

276 (74.6)

332 (76.1)

0.610

 Cough

764 (94.8)

342 (92.4)

422 (96.8)

0.006

 Expectoration

732 (90.8)

322 (87.0)

410 (94.0)

0.001

 Dyspnea

542 (67.2)

245 (66.2)

297 (68.1)

0.566

 White blood cell, × 10⁹/L (IQR)

7.85 (5.62–11.34)

8.20 (5.73–11.71)

7.55 (5.43–10.91)

0.086

 Neutrophils, ×10⁹/L (IQR)

6.17 (3.82–9.22)

6.73 (4.31–9.80)

5.52 (3.51–8.95)

0.014

 Lymphocyte, ×10⁹/L (IQR)

0.95 (0.56–1.52)

0.84 (0.45–1.40)

1.03 (0.61–1.58)

0.001

 Persistent lymphocytopenia

319 (39.6)

177 (47.8)

142 (32.6)

< 0.001

 Mean hemoglobin±SD, g/L

117.8 ± 24.5

110.6 ± 23.6

123.9 ± 23.6

< 0.001

 Mean albumin±SD, g/L

34.4 ± 6.6

33.5 ± 6.6

35.2 ± 6.5

< 0.001

 Lactate dehydrogenase, U/L

302 (217–501)

357 (245–555)

263 (199–454)

< 0.001

 Blood urea nitrogen, mmol/L

5.95 (4.18–9.61)

6.69 (4.61–11.62)

5.39 (3.90–7.89)

< 0.001

 D-Dimer, mmol/L

1.61 (0.69–4.32)

2.06 (0.84–9.42)

1.37 (0.58–3.10)

< 0.001

 Procalcitonin, ng/ml

0.31 (0.17–0.82)

0.32 (0.16–0.72)

0.31 (0.18–0.94)

0.372

 Oxygenation index

203 (118–289)

186 (113–289)

209 (126–292)

0.401

 Severe pneumonia index score

78 (59–103)

83 (62–107)

75 (56–99)

0.001

 CURB65 score > 1

261 (32.4)

117 (31.6)

144 (33.0)

0.671

 Without underlying disease

106 (13.2)

0 (0)

106 (24.3)

< 0.001

 Diabetes mellitus

194 (24.1)

103 (27.8)

91 (20.9)

0.021

 Tumor

62 (7.7)

41 (11.1)

21 (4.8)

0.001

 Connective tissue disease^a

140 (17.4)

134 (36.2)

6 (1.4)

< 0.001

 Interstitial lung disease

210 (26.1)

165 (44.6)

45 (10.3)

< 0.001

 Bronchiectasis

28 (3.5)

6 (1.6)

22 (5.0)

0.008

 Bronchial asthma

17 (2.1)

6 (1.6)

11 (2.5)

0.375

 Chronic obstructive pulmonary disease

85 (10.5)

24 (6.5)

61 (14.0)

0.001

 Cirrhosis

5 (0.6)

5 (1.4)

0 (0)

0.015

 Leukemia

7 (0.9)

7 (1.9)

0 (0)

0.004

 Lymphoma

17 (2.1)

16 (4.3)

1 (0.2)

< 0.001

 Nephrotic syndrome or chronic glomerulonephritis

50 (6.2)

46 (12.4)

4 (0.9)

< 0.001

 Chronic renal failure

45 (5.6)

29 (7.8)

16 (3.7)

0.003

 After bone marrow or hematopoietic stem cell transplantation

5 (0.6)

5 (1.4)

0 (0)

0.015

 Solid organ transplant

60 (7.4)

60 (16.2)

0 (0)

< 0.001

 Current smoker or ex-smoker

287 (35.6)

128 (34.6)

159 (36.5)

0.599

Bronchoalveolar lavage, n (%)

609 (75.6)

271 (73.2)

338 (77.5)

0.159

 Antibiotics

665 (82.5)

280 (75.7)

385 (88.3)

< 0.001

 Antiviral drugs

164 (20.3)

83 (22.4)

81 (18.6)

0.176

 Anti - Pseudomonas aeruginosa drugs

627 (77.8)

295 (79.7)

332 (76.1)

0.223

 Voriconazole or caspofungin

288 (35.7)

181 (48.9)

107 (24.5)

< 0.001

 Ganciclovir

254 (31.5)

221 (59.7)

33 (7.6)

< 0.001

 Trimethoprim

207 (25.7)

193 (52.2)

14 (3.2)

< 0.001

 Noninvasive ventilation

146 (18.1)

90 (24.3)

56 (12.8)

< 0.001

 Invasive mechanical ventilation

234 (29.0)

98 (26.5)

136 (31.2)

0.183

 Mechanical ventilation

310 (38.5)

141 (38.1)

169 (38.8)

0.982

 Respiratory failure during admission

397 (49.3)

186 (50.3)

211 (48.4)

0.379

 ICU admission

349 (43.3)

156 (42.2)

193 (44.3)

0.532

 Septic shock during hospitalization

170 (21.1)

91 (24.6)

79 (18.1)

0.025

 Extracorporeal membrane oxygenation

58 (7.2)

24 (6.5)

34 (7.8)

0.922

 Hospital mortality

180 (22.3)

98 (26.5)

82 (18.8)

0.008