Table 2.
Patients diagnosed with influenza A (H1N1)pdm09 virus: differences between survivors and patients who died, and independent factors related to mortality
| Variable | Survivors | Patients who died | P value | Odds ratio (95 % confidence interval) | P value |
|---|---|---|---|---|---|
| Total patients | 1528 | 395 | |||
| Age (years), mean (SD) | 48.32 (15.24) | 53.08 (15.51) | 0.001 | ||
| Sex | |||||
| Men | 865 (56.6) | 255 (64.6) | 0.004 | ||
| Women | 662 (43.4) | 140 (35.4) | |||
| Seasonal period | |||||
| 2009–2012 | 941 (80.7) | 225 (19.3) | 0.053 | ||
| 2013–2015 | 587 (77.5) | 170 (22.5) | |||
| Influenza vaccine | 65 (4.3) | 26 (6.6) | 0.137 | ||
| Comorbid conditions | |||||
| Asthma | 113 (11.6) | 18 (6.6) | 0.019 | ||
| Chronic obstructive pulmonary disease | 291 (19.0) | 73 (18.5) | 0.824 | ||
| Heart failure | 140 (9.2)) | 53 (13.4) | 0.011 | ||
| Chronic renal failure | 82 (5.4) | 53 (13.4) | 0.001 | ||
| Hematological disease | 65 (4.3) | 52 (13.2) | 0.001 | 1.98 (1.23–3.19) | 0.001 |
| Obesity | 523 (34.2) | 139 (35.2) | 0.683 | ||
| Diabetes mellitus | 212 (13.9) | 65 (16.5) | 0.183 | ||
| Human immunodeficiency virus infection | 26 (1.7) | 17 (4.3) | 0.002 | ||
| Neuromuscular disease | 44 (2.9) | 11 (2.8) | 0.929 | ||
| Autoimmune disease | 45 (2.9) | 20 (5.1) | 0.036 | ||
| Immunosuppression | 99 (6.5) | 89 (22.5) | 0.001 | ||
| Pregnancy | 64(4.2) | 11 (2.8) | 0.203 | ||
| APACHE II score, mean (SD) | 14 (6) | 21 (8) | 0.001 | 1.09 (1.07–1.11) | 0.001 |
| SOFA score, mean (SD) | 5 (3) | 8 (4) | 0.001 | ||
| Presenting clinical manifestations | |||||
| Primary viral pneumonia | 1273 (83.3) | 342 (86.6) | 0.105 | ||
| Coinfection (bacterial pneumonia) | 229 (15.0) | 96 (24.3) | 0.001 | ||
| Noninvasive mechanical ventilation | 527 (34.75 | 141 (35.7) | 0.330 | ||
| Mechanical ventilation | 812 (53.1) | 366 (92.7) | 0.001 | 4.84 (2.73–8.56) | 0.001 |
| Vasoactive drugs | 664 (43.5) | 307 (77.7) | 0.001 | ||
| Decubitus prono | 206 (13.05 | 133 (33.7) | 0.001 | ||
| Continuous venovenous hemofiltration | 67 (4.4) | 116 (29.4) | 0.001 | 4.81 (3.31–7.01) | 0.001 |
| Corticoids | 500 (32.7) | 196 (49.6) | 0,001 | ||
| Days until ICU admission, median (IQR) | 1 (1–2) | 1 (1–3) | 0.001 | 1.05 (0.99–1.11) | 0.117 |
| Length of ICU stay (days), median (IQR) | 8 (4–18) | 9 (4–18) | 0.660 | ||
| Length of hospital stay (days), median (IQR) | 16 (10–30) | 11 (5–21) | 0.001 | ||
| Days until oseltamivir therapy, median (IQR) | 4 (2–6) | 5 (3–6) | 0.054 | ||
| Time of diagnosis | |||||
| Early (≤2 days) | 1035 (67.7) | 214 (54.2) | 0.001 | 1.36 (1.03–1.81) | 0.001 |
| Late (3–7 days) | 493 (32.3) | 181 (45.8) | |||
Data expressed as frequencies (percentages) unless otherwise stated
APACHE Acute Physiology and Chronic Health Evaluation, IQR interquartile range (25th–75th percentile), SD standard deviation, SOFA Sepsis-related Organ Failure Assessment