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Table 2 Patients diagnosed with influenza A (H1N1)pdm09 virus: differences between survivors and patients who died, and independent factors related to mortality

From: Delay in diagnosis of influenza A (H1N1)pdm09 virus infection in critically ill patients and impact on clinical outcome

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)
  1. Data expressed as frequencies (percentages) unless otherwise stated
  2. APACHE Acute Physiology and Chronic Health Evaluation, IQR interquartile range (25th–75th percentile), SD standard deviation, SOFA Sepsis-related Organ Failure Assessment