Table 1.
Demographic and clinical characteristics of patients with influenza pneumonia compared to patients with influenza but without pneumonia
| Influenza without pneumonia (n = 27) | Primary influenza pneumonia (n = 39) | Concomitant/secondary bacterial pneumonia (n = 15) | P‐value | |
|---|---|---|---|---|
| Age, mean ± SD | 36·6 ± 16·3 | 43·1 ± 19·6 | 51·1 ± 23·8 | 0.08 |
| Sex (male), no. (%) | 6 (22·2) | 16 (41·0) | 9 (64·3) | 0.05 |
| Influenza vaccination during 2008–2009 season, no. (%) | 7 (25·9) | 4 (10·3) | 2 (13·3) | 0.22 |
| Body mass index, mean ± SD | 23·2 ± 3·2 | 23·8 ± 3·1 | 22·6 ± 3·7 | 0.48 |
| CURB‐65 score ≥2, no. (%) | – | 7 (17·9) | 8 (53·3) | 0.02 |
| APACHE II score, mean ± SD | – | 12·7 ± 3·7 | 12·4 ± 3·9 | 0.82 |
| Hypoxia (PO2 < 60 mmHg at room air) | – | 7 (17·9) | 5 (33·3) | 0.28 |
| Comorbidities, no. (%) | 7 (25·9) | 11 (28·2) | 8 (53·3) | 0.15 |
| Asthma | 2 (7·4) | 4 (10·3) | 3 (20·0) | 0.45 |
| Chronic obstructive pulmonary diseases | 0 (0) | 0 (0) | 2 (13·3) | 0.01 |
| Interstitial lung diseases | 0 (0) | 0 (0) | 1 (6·7) | 0.11 |
| Cardiovascular diseases | 1 (3·7) | 3 (7·7) | 1 (6·7) | 0.8 |
| Diabetes | 2 (7·4) | 5 (12·8) | 3 (20·0) | 0.49 |
| Chronic renal failure | 0 (0) | 2 (5·1) | 1 (6·7) | 0.44 |
| Liver cirrhosis | 0 (0) | 1 (2·6) | 0 (0) | 0.58 |
| Malignancy | 0 (0) | 2 (5·1) | 2 (13·3) | 0.44 |
| Transplantation | 1 (3·7) | 0 (0) | 0 (0) | 0.36 |
| Neurologic diseases | 1 (3·7) | 0 (0) | 1 (6·7) | 0.32 |
| Immunosuppressant use | 2 (7·4) | 1 (2·6) | 0 (0) | 0.42 |
| Duration of symptoms before hospital visit, mean ± SD | 2·5 ± 1·2a | 3·6 ± 2·2a | 5·0 ± 3·5b | <0.01 |
| Initial symptoms and signs, no. (%) | ||||
| Fever | 25 (92·6) | 35 (89·7) | 12 (80·0) | 0.45 |
| Myalgia | 20 (74·1) | 20 (51·3) | 4 (26·7) | 0.01 |
| Headache | 14 (51·9) | 12 (30·8) | 1 (6·7) | 0.01 |
| Sore throat | 19 (70·4) | 20 (51·3) | 6 (40·0) | 0.13 |
| Cough | 26 (96·3) | 39 (100) | 15 (100) | 0.36 |
| Sputum | 6 (22·2) | 19 (48·7) | 11 (73·3) | 0.01 |
| Hemoptysis | 0 (0) | 1 (2·6) | 1 (6·7) | 0.41 |
| Dyspnea | 10 (37·0) | 21 (53·8) | 10 (66·7) | 0.16 |
| Chest pain | 1 (3·7) | 8 (20·5) | 3 (20·0) | 0.14 |
| Nasal symptoms | 17 (63·0) | 17 (43·6) | 3 (20·0) | 0.03 |
| Nausea/vomiting | 7 (25·9) | 6 (15·4) | 1 (6·7) | 0.26 |
| Diarrhea | 5 (18·5) | 2 (5·1) | 1 (6·7) | 0.18 |
| Gross hematuria | 1 (3·7) | 1 (2·6) | 0 (0) | 0.76 |
| Crackle | 0 (0) | 15 (38·5) | 8 (53·3) | <0.01 |
| Wheezing | 9 (33·3) | 8 (20·5) | 7 (46·7) | 0.15 |
| Death in hospital, no. (%) | 0 (0) | 0 (0) | 2 (13·3) | 0.01 |
| Treatment defervescence interval (days), mean ± SD | 1·1 ± 0·4 | 1·6 ± 1·0 | 1·7 ± 1·2 | 0.07 |
| Duration of hospitalization, mean ± SD | 4·1 ± 1·3a | 8·4 ± 6·7a | 14·5 ± 14·2b | <0.01 |
| ICU admission, no. (%) | – | 10 (25·6) | 7 (46·7) | 0.19 |
| Duration of ICU admission, mean ± SD | – | 2·0 ± 4·0 | 4·3 ± 5·9 | 0.12 |
| Mechanical ventilation, no. (%) | – | 3 (7·7) | 4 (26·7) | 0.09 |
| Shock requiring vasopressors or inotropes, no. (%) | – | 0 (0) | 3 (20·0) | 0.02 |
The same superscript letters indicate a non‐significant difference between groups based on Tukey’s multiple comparison test.
APACHE II, Acute Physiology and Chronic Health Evaluation II; ICU, intensive care unit.