Variable | Total (n = 1313) | IC (n = 122) | Non IC (n = 1191) | p value |
---|---|---|---|---|
Age (yrs, median, IQR) | 59.0 (45.0–76.0) | 45.0 (32.8–55.3) | 61.0 (49.0–78.0) | < 0.001 |
Male (n,%) | 710 (54.1) | 61 (50.0) | 649 (54.5) | 0.343 |
Influenza A infection (n,%) | 459 (35.0) | 35 (28.7) | 424 (35.6) | 0.127 |
Days from illness onset to admission (median, IQR) | 3.0 (2.0–5.0) | 2.0 (1.0–3.0) | 4.0 (2.0–5.0) | < 0.001 |
Comorbidities (n,%) | ||||
Cardiovascular disease | 309 (23.5) | 22 (18.0) | 287 (24.1) | 0.133 |
Diabetes mellitus | 162 (12.3) | 14 (11.5) | 148 (12.4) | 0.761 |
Cerebrovascular disease | 128 (9.7) | 14 (11.5) | 114 (9.6) | 0.500 |
COPD | 117 (8.9) | 15 (12.3) | 102 (8.6) | 0.168 |
Chronic kidney disease | 42 (3.2) | 7 (5.7) | 35 (2.9) | 0.161 |
Asthma | 41 (3.1) | 5 (4.1) | 36 (3.0) | 0.706 |
Obesity (n,%) | 86 (6.5) | 5 (4.1) | 81 (6.8) | 0.250 |
Pregnancy (n,%) | 9 (0.7) | 0 (0.0) | 9 (0.8) | 1.000 |
Smoking history (n,%) | 375 (28.6) | 27 (22.1) | 348 (29.2) | 0.099 |
Baseline clinical and radiologic features (n,%) | ||||
Fever ≥ 38℃ | 990 (75.4) | 78 (63.9) | 912 (76.6) | 0.002 |
Myalgia | 441 (33.6) | 37 (30.3) | 404 (33.9) | 0.424 |
Sore throat | 235 (17.9) | 19 (15.6) | 216 (18.1) | 0.482 |
Cough | 1290 (98.2) | 119 (97.5) | 1171 (98.3) | 0.532 |
Sputum | 1032 (78.6) | 90 (73.8) | 942 (79.1) | 0.172 |
Chest pain | 243 (18.5) | 38 (31.1) | 205 (17.2) | < 0.001 |
Respiratory rates ≥ 30 breaths/min | 178 (13.6) | 19 (15.6) | 159 (13.4) | 0.494 |
Altered mental status | 179 (13.6) | 12 (9.8) | 167 (14.0) | 0.199 |
SBP < 90 mmHg | 21 (1.6) | 4 (3.3) | 17 (1.4) | 0.121 |
Leukocytes (× 109/L, median, IQR) | 6.3 (5.2, 10.0) | 6.3 (4.5, 10.1) | 6.3 (5.2, 10.0) | 0.390 |
Lymphocytes (× 109/L, median, IQR) | 08 (0.6, 1.6), n = 1211 | 0.6 (0.5, 1.0) | 1.0 (0.6, 1.7), n = 1089 | < 0.001 |
HB (g/L, mean ± SD) | 123.1 ± 23.0 | 122.9 ± 23.2 | 123.1 ± 23.0 | 0.907 |
ALB (g/L, mean ± SD) | 28.7 ± 5.4, n = 1169 | 28.4 ± 6.0 | 28.8 ± 5.3, n = 1047 | 0.451 |
BUN (mmol/L, median, IQR) | 5.3 (3.6, 8.3), n = 1221 | 6.6 (3.1, 8.4) | 5.1 (3.1, 8.4), n = 1099 | 0.348 |
PaO2/FiO2 (mmHg, median, IQR) | 317.5 (249.0, 347.0), n = 1170 | 317.5 (266.3, 340.0) | 316.2 (244.4, 458.6), n = 1048 | 0.678 |
Multilobar infiltrates | 958 (73.0) | 85 (69.7) | 873 (73.3) | 0.390 |
Pleural effusion | 439 (33.4) | 58 (47.5) | 381 (32.0) | 0.001 |
Coinfection (n, %) | 458 (34.9) | 53 (43.4) | 405 (34.0) | 0.037 |
Clinical treatment and outcomes | ||||
Early NAI therapy (n,%) | 495 (37.7) | 55 (45.1) | 437 (36.7) | 0.068 |
Systemic corticosteroids use at admission (n,%) | 116 (8.8) | 32 (26.2) | 84 (7.1) | < 0.001 |
Noninvasive ventilation (n,%) | 365 (27.8) | 59 (48.4) | 306 (25.7) | < 0.001 |
Invasive ventilation (n,%) | 248 (18.9) | 37 (30.3) | 211 (17.7) | 0.001 |
Complications during hospitalization (n,%) | ||||
Respiratory failure | 323 (24.6) | 50 (41.0) | 273 (22.9) | < 0.001 |
Heart failure | 327 (24.9) | 42 (34.4) | 285 (23.9) | 0.011 |
Nosocomial pneumonia | 109 (8.3) | 21 (17.2) | 88 (7.4) | < 0.001 |
Septic shock | 119 (9.1) | 24 (19.7) | 95 (8.0) | < 0.001 |
Nosocomial BSI | 18 (1.4) | 9 (7.4) | 9 (0.8) | < 0.001 |
Acute renal failure | 79 (0.6) | 8 (6.6) | 71 (6.0) | 0.592 |
Admittance to ICU (n,%) | 326 (24.8) | 59 (48.4) | 267 (22.4) | < 0.001 |
Days from clinical stability to admission (median, IQR) | 3.0 (1.0–9.0) | 14.0 (10.0–19.0) | 3.0 (1.0–8.0) | < 0.001 |
Length of stay in hospital (days, median, IQR) | 10.0 (8.0–17.0) | 17.0 (11.0–22.0) | 10.0 (8.0–14.0) | < 0.001 |
30-day mortality (n,%) | 315 (24.0) | 46 (37.7) | 242 (20.3) | < 0.001 |