Table 1.
Relative odds and 95% confidence intervals of ASD by birth month with respect to January
| Denmark | Finland | Norway | Sweden | Western Australia | |
|---|---|---|---|---|---|
| Jan | Ref. | Ref. | Ref. | Ref. | Ref. |
| Feb | 1.09 (1.00, 1.18) | 1.00 (0.89, 1.13) | 0.74 (0.56, 0.99) | 1.01 (0.93, 1.10) | 0.98 (0.73, 1.32) |
| Mar | 0.99 (0.91, 1.08) | 0.99 (0.88, 1.11) | 0.93 (0.72, 1.21) | 1.01 (0.93, 1.09) | 0.94 (0.70, 1.26) |
| Apr | 1.00 (0.91, 1.08) | 1.07 (0.95, 1.20) | 0.81 (0.62, 1.07) | 0.99 (0.91, 1.07) | 1.16 (0.87, 1.54) |
| May | 1.02 (0.94, 1.11) | 0.99 (0.88, 1.11) | 1.04 (0.81, 1.35) | 1.08 (1.00, 1.17) | 0.98 (0.73, 1.32) |
| Jun | 1.07 (0.98, 1.16) | 1.01 (0.90, 1.13) | 1.04 (0.80, 1.35) | 1.02 (0.94, 1.11) | 0.91 (0.67, 1.23) |
| Jul | 1.04 (0.95, 1.13) | 1.14 (1.02, 1.27) | 1.06 (0.82, 1.37) | 1.13 (1.04, 1.22) | 1.03 (0.77, 1.37) |
| Aug | 1.01 (0.93, 1.10) | 1.10 (0.98, 1.23) | 0.92 (0.70, 1.21) | 1.05 (0.97, 1.14) | 1.22 (0.92, 1.61) |
| Sep | 1.11 (1.02, 1.21) | 1.12 (1.00, 1.25) | 1.02 (0.78, 1.33) | 1.16 (1.07, 1.26) | 1.1 (0.82, 1.45) |
| Oct | 1.07 (0.98, 1.17) | 1.21 (1.08, 1.35) | 0.99 (0.76, 1.30) | 1.19 (1.09, 1.29) | 0.94 (0.70, 1.26) |
| Nov | 1.06 (0.98, 1.16) | 1.11 (0.99, 1.25) | 1.03 (0.78, 1.35) | 1.24 (1.14, 1.34) | 1.15 (0.87, 1.54) |
| Dec | 1.03 (0.95, 1.13) | 1.18 (1.05, 1.32) | 1.18 (0.91, 1.53) | 1.25 (1.15, 1.35) | 1.00 (0.74, 1.34) |
Bold values indicate p < 0.05