Table 2 Comparison of cases (hospitalized patients) and controls (outpatients) with confirmed pandemic influenza A (H1N1) 2009
Independent variables | Cases (N = 699) | Controls (N = 699) | Crude OR (95%) | Adjusted OR (95%) | |
|---|---|---|---|---|---|
Sex | Male | 342 | 301 | 1 | 1 |
Female | 356 | 397 | 0.79 (0.61 – 1.01) | 0.72 (0.51 – 1.01) | |
Ethnicity | White | 588 | 634 | 1 | 1 |
Other | 88 | 42 | 2.39** (1.45 – 3.98) | 2.18** (1.17 – 4.08) | |
Educational level | No/primary education | 263 | 152 | 1 | 1 |
Secondary or higher | 387 | 498 | 0.38** (0.27 – 0.53) | 0.56** (0.36 – 0.87) | |
Overcrowding | > = 29 m2 | 234 | 252 | 1 | 1 |
28 – 15 m2 | 237 | 240 | 1.07 (0.78 – 1.49) | 1.09 (0.76 – 1.57) | |
<= 14 m2 | 41 | 20 | 3* (1.04 – 10.55) | 2.84* (1.20 – 6.72) | |
Unfavourable medical factors | 0 | 242 | 382 | 1 | 1 |
1 | 230 | 238 | 1.78** (1.25 – 2.53) | 1.60* (1.07 – 2.40) | |
2 | 122 | 58 | 3.99** (1.99 – 8.03) | 2.94** (1.61 – 5.36) | |
>2 | 105 | 21 | 38** (6.42 – 153.99) | 18.51** (6.08 – 56.41) | |
Previous preventive information | Yes | 577 | 639 | 1 | 1 |
No | 122 | 60 | 2.38** (1.56 – 3.66) | 2.69** (1.50 – 4.83) | |
Prior pandemic vaccination | No | 691 | 697 | 1 | 1 |
Yes | 7 | 1 | – | – | |
Previous outpatient care | No | 357 | 557 | 1 | 1 |
Yes | 342 | 142 | 4.57** (3.23 – 6.51) | 3.46** (2.22 – 5.39) | |
Previous emergency care | No | 488 | 603 | 1 | 1 |
Yes | 211 | 96 | 3.02** (2.10 – 4.35) | 2.68** (1.66 – 4.32) | |