Table 2 Comparative analyses between severe and non-severe infection cases

Sex, (female), n(%)

282 (49.2%)

46 (49.5%)

0.965

Age (IQR)

67 (53–77)

64 (54–75)

0.408

Smoking, n(%)

163 (28.4%)

35 (37.6%)

0.072

COPD *, n(%)

143 (25%)

17 (18.3%)

0.162

Pregnancy, n(%)

3 (0.5%)

2 (2.2%)

0.145

Obesity, n(%)

75 (13.1%)

18 (19.4%)

0.106

Cardiac disease, n(%)

182 (31.8%)

39 (41.9%)

0.058

Chronic kidney disease, n(%)

69 (12%)

15 (16.1%)

0.271

Diabetes, n(%)

159 (27.7%)

33 (35.5%)

0.136

Immunosuppression, n(%)

 HIV**, n(%)

38 (6.6%)

7 (7.5%)

0.75

 Malignancy, n(%)

35 (6.1%)

7 (7.5%)

0.602

 Corticotherapy, n(%)

16 (2.8%)

2 (2.2%)

1

 Others, n(%)

24 (4.7%)

4 (4.3%)

1

Vaccinated, n(%)

232 (40.5%)

26 (28%)

0.021

Subtype, n(%)

0.571

H1N1

204 (35.6%)

38 (40.9%)

H3N2

207 (36.1%)

34 (36.6%)

Influenza A no subtype

28 (4.9%)

5 (5.4%)

Influenza B

134 (23.4%)

16 (17.2%)

Cough, n(%)

500 (87.3%)

73 (78.5%)

0.024

Fever, n(%)

410 (71.6%)

66 (71%)

0.908

Myalgia, n(%)

148 (25.8%)

18 (19.4%)

0.181

Dyspnoea, n(%)

376 (65.5%)

70 (75.3%)

0.066

State of confusion, n(%)

39 (6.8%)

25 (26.9%)

< 0.001

Heart rate, median (IQR), n total

96 (83–108)

97.5 (80.5-111.5)

0.532

Systolic blood pressure [mmHg], median (IQR), n total

131 (114.5–147)

122 (108–145)

0.03

Respiratory frequency, median (IQR), n

24 (20-30.5)

30 (24.5–36)

< 0.001

Oxygen saturation [%], median (IQR), n

94 (91–96)

93 (88–96)

0.14

Oxygen saturation < 93%, n(%)

218 (38.6%)

44 (48.9%)

0.064

Horowitz Index (PaO₂/FiO₂⁾, median (IQR), n

280.2 (247.6-309.5)

261.9 (140-309.5)

0.001

Lymphocyte [x10⁹/L] median (IQR), n

1050 (700–1470)

810 (530–1140)

< 0.001

Hematocrit [%], median (IQR), n

39.6 (35.3–42.9)

34.8 (30.3–41.7)

< 0.001

Platelet [x109/L], median (IQR)

201,000(151,000–257,000)

202,000(154,000–260,000)

0.96

Creatinine [mg/dl], median (IQR), n

0.9 (0.7–1.1)

1 (0.8–1.8)

0.041

Urea [mg/d], median (IQR), n

36 (28–50)

53 (34–75)

< 0.001

Albumin [mg/dl], median (IQR), n

35 (32-37.8)

28.5 (24.9–32.4)

< 0.001

C-reactive protein [mg/dl], median (IQR), n

4.7 (1.9–10.9)

12.3 (4.3–23.4)

< 0.001

Pneumonia, n(%)

132 (23%)

53 (57%)

< 0.001

Pleural effusion, n (%)

15 (2.6%)

13 (14%)

< 0.001

Septic shock, n(%)

4 (0.7%)

46 (49.5%)

< 0.001

Mechanical ventilation, n(%)

9 (1.6%)

58 (62.4%)

< 0.001

ARDS***, n (%)

1 (0.2%)

10 (10.8%)

< 0.001

Coinfection, n (%)

36 (6.3%)

24 (25.8%)

< 0.001

Nosocomial infection, n (%)

56 (9.8%)

20 (21.5%)

0.001