Table 1.
Characteristics of patients admitted to ICUsa
| Characteristics | Influenza-positive/total, n (%) | |
|---|---|---|
| 2007/2008 and 2008/2009 influenza seasons | 2009 H1N1 pandemic, second wave | |
| Total number of patients | 97/2,171 (4.5) | 29/245 (11.8) |
| Gender | ||
| Males | 50/1,197 (4.2) | 19/127 (15.0) |
| Females | 46/972 (4.7) | 10/118 (8.5) |
| Age, years | ||
| All patients, median (IQR) | 72.0 (59.4 to 80.5) | 67.5 (52.8 to 79.7) |
| 18 to 44 | 6/168 (3.6) | 9/35 (25.7) |
| 45 to 64 | 24/596 (4.0) | 14/78 (18.0) |
| 65 to 84 | 54/1,147 (4.7) | 6/107 (5.6) |
| ≥85 | 13/260 (5.0) | 0/25 (0.0) |
| Admitted from long-term care facility | 7/95 (7.4) | 4/13 (30.8) |
| Temperature on admission, °C | ||
| All patients, years, median (IQR) | 36.6 (36.0 to 37.2) | 36.7 (36.2 to 37.5) |
| <38.0°C | 74/1,964 (3.8) | 18/217 (8.3) |
| ≥38.0°C | 23/207 (11.1) | 11/28 (39.3) |
| Respiratory symptoms upon hospital admission | ||
| Absent | 9/628 (1.4) | 1/55 (1.8) |
| Present | 87/1,449 (6.0) | 27/184 (14.7) |
| Admission diagnosis | ||
| Respiratory infectionb | 34/298 (11.4) | 17/49 (34.7) |
| Respiratory failurec | 22/212 (10.4) | 3/25 (12.0) |
| Sepsis/fever | 4/101 (4.0) | 2/15 (13.3) |
| Any cardiac diagnosis | 26/939 (2.8) | 3/52 (5.8) |
aIQR: interquartile range; b'pneumonia' and 'other respiratory infection'; c'chronic obstructive pulmonary disease exacerbation', 'asthma exacerbation' and 'respiratory failure'.