Influenza-negative | Influenza-positive | A(H1N1)pdm09 | A (H3N2) | A not subtyped | B/Yamagata | B/Victoria | B not subtyped | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
N=7245 | N=2895 | N=76 | N=1840 | N=129 | N=108 | N=618 | N=135 | |||||||||||
Category | n | % | n | % | P vs. negative | n | % | n | % | n | % | n | % | n | % | n | % | P-value for distribution by strain |
Severity indicator | ||||||||||||||||||
Intensive care unit admission | 317 | 4.4 | 132 | 4.6 | 0.6656 | 9 | 11.8 | 102 | 5.5 | 5 | 3.9 | 5 | 4.6 | 6 | 1.0 | 6 | 4.4 | <0.0001 |
Mechanical ventilation | 225 | 3.1 | 75 | 2.6 | 0.1728 | 5 | 6.6 | 61 | 3.3 | 3 | 2.3 | 2 | 1.9 | 3 | 0.5 | 2 | 1.5 | 0.0018 |
Extracorporeal membrane oxygenation | 89 | 1.2 | 9 | 0.3 | 0.0000 | 0 | 0.0 | 5 | 0.3 | 3 | 2.3 | 0 | 0.0 | 1 | 0.2 | 0 | 0.0 | 0.0035 |
Death during hospitalisation | 183 | 2.5 | 69 | 2.4 | 0.6904 | 4 | 5.3 | 52 | 2.8 | 3 | 2.3 | 3 | 2.8 | 5 | 0.8 | 2 | 1.5 | 0.0745 |
Length of stay (days), median (interquartile range) | 6 | (3-8) | 5 | (3-8) | <0.001 | 6 | (3-10) | 5 | (3-8) | 6 | (3-9) | 4 | (2-6.5) | 6 | (4-8) | 5 | (3-7) | 0.004 |
Respiratory diagnoses | <0.0001 | 0.3163 | ||||||||||||||||
None | 2052 | 28.3 | 1828 | 63.1 | 15 | 19.7 | 1191 | 64.7 | 79 | 61.2 | 51 | 47.2 | 435 | 70.4 | 60 | 44.4 | ||
Pneumonia | 2335 | 32.2 | 658 | 22.7 | 58 | 76.3 | 362 | 19.7 | 37 | 28.7 | 40 | 37.0 | 112 | 18.1 | 55 | 40.7 | ||
COPD exacerbation | 192 | 2.7 | 91 | 3.1 | 2 | 2.6 | 74 | 4.0 | 5 | 3.9 | 3 | 2.8 | 3 | 0.5 | 4 | 3.0 | ||
Respiratory failure | 109 | 1.5 | 12 | 0.4 | 1 | 1.3 | 9 | 0.5 | 1 | 0.8 | 0 | 0.0 | 0 | 0.0 | 1 | 0.7 | ||
Asthma exacerbation | 53 | 0.7 | 30 | 1.0 | 0 | 0.0 | 29 | 1.6 | 0 | 0.0 | 0 | 0.0 | 1 | 0.2 | 0 | 0.0 | ||
Acute respiratory distress syndrome | 18 | 0.2 | 2 | 0.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 2 | 0.3 | 0 | 0.0 | ||
Pneumotorax | 1 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Bronchiolitis | 383 | 5.3 | 48 | 1.7 | 0 | 0.0 | 29 | 1.6 | 1 | 0.8 | 0 | 0.0 | 12 | 1.9 | 6 | 4.4 | ||
Upper respiratory infection | 2101 | 29.0 | 226 | 7.8 | 0 | 0.0 | 146 | 7.9 | 6 | 4.7 | 14 | 13.0 | 53 | 8.6 | 9 | 6.7 | ||
Metabolic failure | 0.1725 | 0.2106 | ||||||||||||||||
No | 7016 | 96.8 | 2827 | 97.7 | 72 | 94.7 | 1803 | 98.0 | 126 | 97.7 | 106 | 98.1 | 604 | 97.7 | 127 | 94.1 | ||
Acute renal failure | 85 | 1.2 | 19 | 0.7 | 3 | 3.9 | 10 | 0.5 | 2 | 1.6 | 2 | 1.9 | 0 | 0.0 | 2 | 1.5 | ||
Diabetic coma | 8 | 0.1 | 1 | 0.0 | 0 | 0.0 | 1 | 0.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Fluid/electrolyte/acid-base/balance disorders | 136 | 1.9 | 48 | 1.7 | 1 | 1.3 | 26 | 1.4 | 1 | 0.8 | 0 | 0.0 | 14 | 2.3 | 6 | 4.4 | ||
Cardiovascular events | <0.0001 | <0.0001 | ||||||||||||||||
None | 6674 | 92.1 | 2766 | 95.5 | 69 | 90.8 | 1741 | 94.6 | 122 | 94.6 | 104 | 96.3 | 611 | 98.9 | 129 | 95.6 | ||
Acute myocardial infarction | 6 | 0.1 | 1 | 0.0 | 0 | 0.0 | 1 | 0.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Arterial or venous embolia | 1 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Carditis | 2 | 0.0 | 1 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 1 | 0.2 | 0 | 0.0 | ||
Cardiac arrest | 1 | 0.0 | 1 | 0.0 | 0 | 0.0 | 1 | 0.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Malignant hypertension | 1 | 0.0 | 3 | 0.1 | 0 | 0.0 | 2 | 0.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 1 | 0.7 | ||
Any cardiovascular condition | 560 | 7.7 | 123 | 4.2 | 7 | 9.2 | 95 | 5.2 | 7 | 5.4 | 4 | 3.7 | 6 | 1.0 | 5 | 3.7 | ||
Neurologic events | 0.4268 | 0.4345 | ||||||||||||||||
No | 7241 | 99.9 | 2894 | 100.0 | 76 | 100.0 | 1839 | 99.9 | 129 | 100.0 | 108 | 100.0 | 618 | 100.0 | 135 | 100.0 | ||
Altered mental status | 3 | 0.0 | 1 | 0.0 | 0 | 0.0 | 1 | 0.1 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Convulsions | 1 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
Major discharge diagnoses | <0.0001 | <0.0001 | ||||||||||||||||
Influenza | 241 | 3.3 | 2272 | 78.5 | 40 | 52.6 | 1401 | 76.1 | 97 | 75.2 | 39 | 36.1 | 584 | 94.5 | 113 | 83.7 | ||
Pneumonia | 2427 | 33.5 | 238 | 8.2 | 31 | 40.8 | 145 | 7.9 | 12 | 9.3 | 29 | 26.9 | 13 | 2.1 | 12 | 8.9 | ||
Other respiratory disease | 2683 | 37.0 | 177 | 6.1 | 1 | 1.3 | 132 | 7.2 | 8 | 6.2 | 15 | 13.9 | 17 | 2.8 | 6 | 4.4 | ||
Cardiovascular | 267 | 3.7 | 34 | 1.2 | 1 | 1.3 | 31 | 1.7 | 1 | 0.8 | 1 | 0.9 | 0 | 0.0 | 1 | 0.7 | ||
Other | 1627 | 22.5 | 174 | 6.0 | 3 | 3.9 | 131 | 7.1 | 11 | 8.5 | 24 | 22.2 | 4 | 0.6 | 3 | 2.2 |