Table 1 Characteristics of hospitalized adult patients with community-acquired influenza included in this study
Variables | Total patients (N = 174) | All-cause in-hospital mortality | Secondary bacterial pneumonia | ||||
|---|---|---|---|---|---|---|---|
Died patients (n = 20) | Survived patients (n = 154) | p value | Patients with secondary bacterial pneumonia (n = 25) | Patients without secondary bacterial pneumonia (n = 149) | p value | ||
Influenza season, n (%) | |||||||
2017 | 36 (20.7) | 8 (40.0) | 28 (18.2) | 0.049 | 5 (20.0) | 31 (20.8) | 0.975 |
2018 | 108 (62.1) | 9 (45.0) | 99 (64.3) | 16 (64.0) | 92 (61.7) | ||
2019 | 30 (17.2) | 3 (15.0) | 27 (17.5) | 4 (16.0) | 26 (17.4) | ||
Type of influenza virus (A or/and B), n (%) | |||||||
Type A | 157 (90.2) | 19 (95.0) | 138 (89.6) | 0.716 | 23 (92.0) | 134 (89.9) | 1.000 |
Type B | 15 (8.6) | 1 (5.0) | 14 (9.1) | 1 (4.0) | 14 (9.4) | ||
Type A and Type B | 2 (1.1) | 0 (0.0) | 2 (1.3) | 1 (4.0) | 1 (0.7) | ||
Age, median (IQR), years | 61.5 (44.0–71.0) | 65.0 (52.8–71.0) | 60.0 (43.0–71.0) | 0.176 | 68.0 (53.0–72.0) | 59.0 (43.0–71.0) | 0.101 |
Age ≥ 65 years, n (%) | 72 (41.4) | 12 (60.0) | 60 (39.0) | 0.072 | 16 (64.0) | 56 (37.6) | 0.013 |
Male gender, n (%) | 106 (60.9) | 16 (80.0) | 90 (58.4) | 0.063 | 22 (88.0) | 84 (56.4) | 0.003 |
Underlying disease, n (%) | 123 (70.7) | 18 (90.0) | 105 (68.2) | 0.044 | 21 (84.0) | 102 (68.5) | 0.114 |
Hypertension | 48 (27.6) | 9 (45.0) | 39 (25.3) | 0.064 | 11 (44.0) | 37 (24.8) | 0.047 |
Diabetes | 38 (21.8) | 6 (30.0) | 32 (20.8) | 0.515 | 8 (32.0) | 30 (20.1) | 0.184 |
Chronic pulmonary disease | 30 (17.2) | 2 (10.0) | 28 (18.2) | 0.551 | 7 (28.0) | 23 (15.4) | 0.210 |
COPD | 28 (16.1) | 2 (10.0) | 26 (16.9) | 0.642 | 6 (24.0) | 22 (14.8) | 0.385 |
Asthma | 4 (2.3) | 1 (5.0) | 3 (1.9) | 0.389 | 1 (4.0) | 3 (2.0) | 0.465 |
TB | 3 (1.7) | 0 (0.0) | 3 (1.9) | 1.000 | 1 (4.0) | 2 (1.3) | 0.374 |
Chronic heart diseasea | 37 (21.3) | 5 (25.0) | 32 (20.8) | 0.886 | 4 (16.0) | 33 (22.1) | 0.487 |
Chronic renal disease | 12 (6.9) | 2 (10.0) | 10 (6.5) | 0.910 | 1 (4.0) | 11 (7.4) | 0.848 |
Chronic liver disease | 29 (16.7) | 4 (20.0) | 25 (16.2) | 0.915 | 3 (12.0) | 26 (17.4) | 0.699 |
Haematological disease | 11 (6.3) | 1 (5.0) | 10 (6.5) | 1.000 | 1 (4.0) | 10 (6.7) | 0.943 |
Cerebrovascular disease | 10 (5.7) | 0 (0.0) | 10 (6.5) | 0.507 | 2 (8.0) | 8 (5.4) | 0.953 |
Malignancy | 18 (10.3) | 2 (10.0) | 16 (10.4) | 1.000 | 4 (16.0) | 14 (9.4) | 0.517 |
Current smoker, n (%) | 53 (30.5) | 10 (50.0) | 43 (27.9) | 0.044 | 11 (44.0) | 42 (28.2) | 0.112 |
Self-reported symptoms on admission, n (%) | |||||||
Fever | 144 (82.8) | 17 (85.0) | 127 (82.5) | 1.000 | 20 (80.0) | 124 (83.2) | 0.914 |
Cough | 159 (91.4) | 20 (100.0) | 139 (90.3) | 0.300 | 23 (92.0) | 136 (91.3) | 1.000 |
Sore throat | 26 (14.9) | 0 (0.0) | 26 (16.9) | 0.097 | 2 (8.0) | 24 (16.1) | 0.454 |
Dyspnoea | 38 (21.8) | 7 (35.0) | 31 (20.1) | 0.220 | 7 (28.0) | 31 (20.8) | 0.420 |
Chest pain | 9 (5.2) | 1 (5.0) | 8 (5.2) | 1.000 | 2 (8.0) | 7 (4.7) | 0.840 |
Muscle or body aches | 32 (18.4) | 1 (5.0) | 31 (20.1) | 0.181 | 1 (4.0) | 31 (20.8) | 0.084 |
Fatigue | 38 (21.8) | 5 (25.0) | 33 (21.4) | 0.939 | 3 (12.0) | 35 (23.5) | 0.198 |
Headaches | 16 (9.2) | 0 (0.0) | 16 (10.4) | 0.271 | 1 (4.0) | 15 (10.1) | 0.550 |
Gastrointestinal symptoms | 19 (10.9) | 4 (20.0) | 15 (9.7) | 0.316 | 3 (12.0) | 16 (10.7) | 1.000 |
The laboratory findings on admission | |||||||
Neutropeniab, n (%) | 2/173 (1.2) | 0 (0.0) | 2/153 (1.3) | 1.000 | 0 (0.0) | 2/148 (1.4) | 1.000 |
Lymphocytopeniac, n (%) | 32/172 (18.6) | 9 (45.0) | 23/152 (15.1) | 0.003 | 5 (20.0) | 27/147 (18.4) | 1.000 |
Thrombocytopeniad, n (%) | 37/173 (21.4) | 9 (45.0) | 28/153 (18.3) | 0.014 | 6 (24.0) | 31/148 (20.9) | 0.731 |
Anaemiae, n (%) | 52/173 (30.1) | 12 (60.0) | 40/153 (26.1) | 0.002 | 13 (52.0) | 39/148 (26.4) | 0.010 |
Hypoalbuminemiaf, n (%) | 45/172 (26.2) | 13 (65.0) | 32/152 (21.1) | < 0.001 | 12 (48.0) | 33/147 (22.4) | 0.007 |
The first radiographic findings after admission, n (%) | |||||||
Pleural effusion | 37/163 (22.7) | 5/18 (27.8) | 32/145 (22.1) | 0.805 | 10/23 (43.5) | 27/140 (19.3) | 0.010 |
Diffuse bilateral pulmonary infiltration | 22/163 (13.5) | 7/18 (38.9) | 15/145 (10.3) | 0.003 | 3/23 (13.0) | 19/140 (13.6) | 1.000 |
Mechanical ventilationg on admission, n (%) | 35 (20.1) | 15 (75.0) | 20 (13.0) | < 0.001 | 11 (44.0) | 24 (16.1) | 0.001 |
Neuraminidase inhibitors treatment, n (%) | 162 (93.1) | 19 (95.0) | 143 (92.9) | 1.000 | 22 (88.0) | 140 (94.0) | 0.508 |
Time from symptom onset to neuraminidase inhibitors treatment, median (IQR), days | 4.5/162 (2.0–8.0) | 5.0/19 (2.0–7.0) | 4.0/143 (2.0–8.0) | 0.845 | 5.5/22 (2.0–8.0) | 4.0/140 (2.0–8.0) | 0.869 |
Neuraminidase inhibitors treatment ≤ 48 h since symptom onset | 44 (25.3) | 5 (25.0) | 39 (25.3) | 0.975 | 6 (24.0) | 38 (25.5) | 0.873 |
Duration of neuraminidase inhibitors treatment, median (IQR), days | 5.9/162 (4.0–9.7) | 8.0/19 (5.4–11.0) | 5.8/143 (3.9–9.5) | 0.141 | 6.4/22 (4.8–13.6) | 5.9/140 (3.9–9.2) | 0.113 |
Secondary bacterial pneumonia, n (%) | 25 (14.4) | 7 (35.0) | 18 (11.7) | 0.014 | – | – | – |
Time from symptom onset to secondary bacterial pneumonia, median (IQR), days | 8.0/25 (4.5–15.0) | 9.0/7 (3.0–19.0) | 7.5/18 (4.8–14.5) | 0.976 | – | – | – |
Length of hospital stay, median (IQR), days | 11.0 (6.0–17.0) | 10.0 (6.0–14.0) | 11.0 (6.0–17.0) | 0.394 | 14.0 (7.0–19.0) | 11.0 (6.0–16.0) | 0.131 |