Table 1. Hospitalizations, mechanical ventilation and fatal cases in seasonal influenza waves and the 2009 pandemic.
| Hospitalizations | ||||||
| Seasonal Flu | Pandemic Flu | Pandemic vs. Seasonal | ||||
| Gender | N (% All) | Hospitalization Rate | N (% All) | Hospitalization Rate | unadj. OR (CI) | p-value |
| Female | 9,704 (46.6) | 3.38 | 6,554 (47.9) | 15.96 | 1.05 (1.01–1.1) | 0.0235 |
| Male | 11,102 (53.4) | 4.05 | 7,133 (52.1) | 18.22 | 0.95 (0.91–0.99) | |
| Age Group | ||||||
| 0–4 | 6,328 (30.4) | 27.07 | 2,989 (21.8) | 89.52 | 0.64 (0.61–0.67) | < 0.0001 |
| 5–14 | 4,623 (22.2) | 8.85 | 3,566 (26.1) | 47.76 | 1.23 (1.17–1.3) | < 0.0001 |
| 15–34 | 3,078 (14.8) | 2.38 | 3,500 (25.6) | 18.95 | 1.98 (1.87–2.09) | < 0.0001 |
| 35–59 | 3,614 (17.4) | 1.74 | 2,711 (19.8) | 9.12 | 1.17 (1.11–1.24) | < 0.0001 |
| > 60 | 3,163 (15.2) | 2.13 | 921 (6.7) | 4.34 | 0.40 (0.37–0.43) | < 0.0001 |
| All | 20,806 (100) | 3.71 | 13,687 (100) | 17.06 | ||
| Mechanical Ventilation | ||||||
| N (% All) | ||||||
| Seasonal Flu | Pandemic Flu | Pandemic vs. Seasonal | ||||
| Gender | N (% All) | MV Rate (%) | N (% All) | MV Rate (%) | unadj. OR (CI) | p-value |
| Female | 651 (63.2) | 6.71 | 356 (58.1) | 5.43 | 0.8 (0.7–0.91) | 0.0009 |
| Male | 379 (36.8) | 3.41 | 257 (41.9) | 3.6 | 1.06 (0.89–1.25) | 0.4968 |
| Age Group | ||||||
| 0–4 | 100 (9.7) | 1.58 | 39 (6.4) | 1.3 | 0.82 (0.57–1.2) | 0.3059 |
| 5–14 | 39 (3.8) | 0.84 | 31 (5.1) | 0.87 | 1.03 (0.64–1.66) | 0.9003 |
| 15–34 | 118 (11.5) | 3.83 | 125 (20.4) | 3.57 | 0.93 (0.72–1.2) | 0.5737 |
| 35–59 | 463 (45) | 12.81 | 302 (49.3) | 11.14 | 0.85 (0.73–0.99) | 0.0436 |
| > 60 | 310 (30.1) | 9.8 | 116 (18.9) | 12.6 | 1.33 (1.06–1.66) | 0.0146 |
| All | 1,030 (100) | 4.95 | 613 (100) | 4.48 | 0.9 (0.81–1) | 0.0441 |
| Fatal Cases | ||||||
| N (% All) | ||||||
| Seasonal Flu | Pandemic Flu | Pandemic vs. Seasonal | ||||
| Gender | N (% All) | Fatality Rate (%) | N (% All) | Fatality Rate (%) | unadj. OR (CI) | p-value |
| Female | 362 (62.5) | 3.73 | 168 (57.3) | 2.56 | 0.68 (0.56–0.82) | <0.0001 |
| Male | 217 (37.5) | 1.95 | 125 (42.7) | 1.75 | 0.89 (0.72–1.12) | 0.326 |
| Age Group | ||||||
| 0–4 | 26 (4.5) | 0.41 | 9 (3.1) | 0.3 | 0.73 (0.34–1.56) | 0.4188 |
| 5–14 | 24 (4.1) | 0.52 | 18 (6.1) | 0.5 | 0.97 (0.53–1.79) | 0.928 |
| 15–34 | 48 (8.3) | 1.56 | 37 (12.6) | 1.06 | 0.67 (0.44–1.04) | 0.0719 |
| 35–59 | 219 (37.8) | 6.06 | 145 (49.5) | 5.35 | 0.88 (0.71–1.09) | 0.2294 |
| > 60 | 262 (45.3) | 8.28 | 84 (28.7) | 9.12 | 1.11 (0.86–1.44) | 0.422 |
| All | 579 (100) | 2.78 | 293 (100) | 2.14 | 0.76 (0.66–0.88) | 0.0002 |
The upper panel shows total hospitalizations (N) for different age groups and both sexes. Age and gender proportions are given in parentheses (% of all). The hospitalization rate is given as cases per 100,000 persons per season, of each respective subpopulation. The unadjusted odds (OR) of hospitalization are given to compare seasonal and pandemic influenza. P-values and 95% confidence intervals are given. The middle panel shows the absolute number of patients requiring mechanical ventilation (MV). The age- and gender-specific proportions are given in parentheses (% of all). The age- and gender-specific rates of mechanical ventilation (MV rate) were calculated in relation to the respective group of all hospitalizations. The given odds ratios compare age- and gender-specific MV rates. P-values and 95% confidence intervals are given. The lower panel shows the absolute number of fatal cases for different age groups and both sexes (N). Age- and gender-specific proportions among fatal cases are given in parentheses (% of all). The age- and gender-specific fatality rate is given. The given odds ratios are to compare age- and gender-specific fatality rates. P-values and 95% confidence intervals are given.