The entire child population stratified in two age groups, the HRs show the relationship between the studied risk factors and coeliac disease risk for 1991–2009 period
| Risk factors | Age <2 years (n=161 140) | Age >2 years (n=1 751 064) | ||
|---|---|---|---|---|
| Bivariable | Multivariable | Bivariable | Multivariable | |
| HR (95% CI), p value | HR (95% CI), p value | HR (95% CI), p value | HR (95% CI), p value | |
| Season of birth | ||||
| Winter | 1.00 | 1.00 | 1.00 | 1.00 |
| Spring | 1.14 (1.00 to 1.29), 0.05 | 1.15 (1.02 to 1.31), 0.03 | 1.01 (0.93 to 1.09), 0.83 | 1.01 (0.93 to 1.09), 0.88 |
| Summer | 1.04 (0.91 to 1.19), 0.55 | 1.05 (0.92 to 1.20), 0.47 | 1.14 (1.05 to 1.23), 0.002 | 1.14 (1.05 to 1.23), 0.002 |
| Autumn | 0.91 (0.79 to 1.05), 0.19 | 0.92 (0.79 to 1.06), 0.23 | 1.11 (1.02 to 1.21), 0.02 | 1.12 (1.03 to 1.22), 0.01 |
| Geographical regions | ||||
| North | 1.00 | 1.00 | 1.00 | 1.00 |
| Central | 1.12 (0.96 to 1.31), 0.14 | 1.14 (0.97 to 1.32), 0.11 | 1.11 (1.02 to 1.22), 0.02 | 1.11 (1.02 to 1.22), 0.02 |
| South | 1.13 (0.97 to 1.31), 0.11 | 1.13 (0.98 to 1.32), 0.10 | 1.53 (1.41 to 1.67), <0.001 | 1.53 (1.41 to 1.67), <0.001 |
| Sex | ||||
| Boys | 1.00 | 1.00 | 1.00 | 1.00 |
| Girls | 1.22 (1.10 to 1.34), <0.001 | 1.23 (1.11 to 1.35), <0.001 | 1.79 (1.69 to 1.90), <0.001 | 1.79 (1.69 to 1.89), <0.001 |
Season of birth is grouped as follows: winter (December, January, February), spring (March, April, May), summer (June, July, August) and autumn (September, October, November). Region of birth is grouped according to the administrative division of nomenclature of territorial units for statistics (NUTS 1) regions.