Table 4 Odds ratios for physician-diagnosed AD by birth season stratified by maternal allergic history and sex
Season of birth | Case | Subtotal | Prevalence | cOR (95% CI) | aOR (95% CI) |
|---|---|---|---|---|---|
Boys without maternal history of allergic disease (n = 20,715) | |||||
Spring (Apr–Jun) | 169 | 4,925 | 3.4% | Reference | Reference |
Summer (Jul–Sep) | 205 | 6,105 | 3.4% | 0.98 (0.80–1.20) | 0.98 (0.79–1.22) |
Autumn (Oct–Dec) | 231 | 5,102 | 4.5% | 1.34 (1.09–1.63) | 1.25 (1.01–1.55) |
Winter (Jan–Mar) | 157 | 4,583 | 3.4% | 1.00 (0.80–1.25) | 0.95 (0.75–1.19) |
Girls without maternal history of allergic disease (n = 19,689) | |||||
Spring (Apr–Jun) | 101 | 4,632 | 2.2% | Reference | Reference |
Summer (Jul–Sep) | 120 | 5,702 | 2.1% | 0.96 (0.74–1.26) | 0.96 (0.72–1.26) |
Autumn (Oct–Dec) | 145 | 4,970 | 2.9% | 1.35 (1.04–1.74) | 1.29 (0.99–1.69) |
Winter (Jan–Mar) | 70 | 4,385 | 1.6% | 0.73 (0.54–0.99) | 0.72 (0.52–0.98) |
Boys with maternal history of allergic disease (n = 20,981) | |||||
Spring (Apr–Jun) | 279 | 4,933 | 5.7% | Reference | Reference |
Summer (Jul–Sep) | 444 | 6,055 | 7.3% | 1.32 (1.13–1.54) | 1.36 (1.15–1.60) |
Autumn (Oct–Dec) | 399 | 5,271 | 7.6% | 1.37 (1.17–1.60) | 1.37 (1.16–1.62) |
Winter (Jan–Mar) | 297 | 4,722 | 6.3% | 1.12 (0.95–1.33) | 1.16 (0.97–1.38) |
Girls with maternal history of allergic disease (n = 19,816) | |||||
Spring (Apr–Jun) | 180 | 4,573 | 3.9% | Reference | Reference |
Summer (Jul–Sep) | 262 | 5,683 | 4.6% | 1.18 (0.97–1.43) | 1.20 (0.98–1.48) |
Autumn (Oct–Dec) | 251 | 5,033 | 5.0% | 1.28 (1.05–1.56) | 1.34 (1.09–1.64) |
Winter (Jan–Mar) | 164 | 4,527 | 3.6% | 0.92 (0.74–1.14) | 0.97 (0.78–1.22) |