Risk for coeliac disease before 2 years of age by season of birth, gender, and time period
| 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) | |