Background variables | Bivariate analyses* RR (95% CI)‡ | Multivariate analysis† RR (95% CI) |
---|---|---|
*Poisson regression analyses based on 1634 cases and 1 210 104 person years of follow up. †Likelihood ratio statistics (LRS) on 6 degrees of freedom (DF)=3 147, p<0.001. ‡Relative risk (95% confidence intervals). §, Interaction term. | ||
Season of birth | ||
Winter | 1.0 | 1.0 |
Summer | 1.3 (1.1 to 1.4) | 1.4 (1.2 to 1.7) |
Gender | ||
Boys | 1.0 | 1.0 |
Girls | 1.9 (1.7 to 2.1) | 2.1 (1.8 to 2.5) |
Time period | ||
1973–1984 | 1.0 | 1.0 |
1985–1995 | 2.9 (2.5 to 3.3) | 2.9 (2.5 to 3.3) |
1996–1997 | 1.2 (1.0 to 1.5) | 1.2 (1.0 to 1.5) |
Season of birth: Gender§ | ||
Boys | 1.0 | |
Girls | 0.83 (0.68 to 1.0) | |
Season of birth: Time period | Excluded from the model | |
1973–1984 | 1.0 | |
1985–1995 | 1.0 (0.77 to 1.3) | |
1996–1997 | 1.3 (0.85 to 2.1) |