Association of significant risk factors from primary model with wheeze in the second year of life by centre
| Reykjavik | Southampton | Amsterdam | Berlin | Lodz | Vilnius | Madrid | Milan | Athens | |
| n | 829 | 494 | 569 | 1228 | 1084 | 1009 | 826 | ||
| Male gender (vs female) | 1.45 (1.02 to 2.08) (0.040) | 1.66 (1.00 to 2.76) (0.050) | 3.17 (1.67 to 6.01) (<0.001) | 1.72 (0.84 to 1.63) (0.346) | 1.28 (0.45 to 3.65) (0.643) | 2.00 (0.74 to 5.32) (0.167) | 1.02 (0.46 to 2.25) (0.966) | – | – |
| Mother smoking at 1-year follow-up (yes vs no) | 1.08 (0.64 to 1.83) (0.776) | 2.72 (1.29 to 5.77) (0.009) | 1.46 (0.75 to 2.86) (0.267) | 1.27 (0.84 to 1.94) (0.258) | 2.38 (0.75 to 7.55) (0.141) | 0.79 (0.11 to 5.99) (0.823) | 1.66 (0.68 to 4.05) (0.261) | – | – |
| Day care at any time in first 2 years of life (yes vs no) | 1.30 (0.41 to 4.09) (0.656) | 1.16 (0.69 to 1.95) (0.570) | 1.71 (0.67 to 4.34) (0.258) | 1.67 (1.01 to 2.77) (0.047) | 1.91 (0.65 to 5.61) (0.237) | 3.66 (1.47 to 9.13) (0.005) | 0.69 (0.31 to 1.53) (0.365) | – | – |
| LRTIs in first year of life (≥quarterly vs ≤one) | 1.83 (1.28 to 2.65) (0.001) | 1.85 (0.82 to 4.17) (0.138) | 2.33 (0.56 to 9.63) (0.243) | 1.30 (0.63 to 2.66) (0.478) | 2.48 (0.32 to 19.18) (0.384) | 24.9 (2.98 to 207.18) (0.003) | 2.42 (0.86 to 6.80) (0.093) | – | – |
| LRTIs in second year of life (≥quarterly vs ≤one) | 2.74 (1.92 to 3.92) (<0.001) | 1.07 (0.41 to 2.75) (0.896) | 2.67 (0.65 to 11.15) (0.174) | 1.29 (0.69 to 2.39) (0.421) | 10.23 (1.34 to 78.33) (0.025) | – | 11.83 (4.27 to 32.78) (<0.001) | – | – |
Values represent: adjusted incidence rate ratio (95% CIs) (P value)*.
Where no figures are entered, Poisson estimation was not possible.
*Only significant associations from the primary model (gender, mother smoking at 1-year follow-up, day care attendance and LRTIs in the first and second years of life) were entered into the multivariable models for individual centres.
LRTIs, lower respiratory tract infections.