Initial analysis of the yearly prevalence of each congenital abnormality group for 1957-73
| Model | Deviance | df | Difference in deviance | df | p Value |
|---|---|---|---|---|---|
| Anencephaly | |||||
| Constant prevalence | 110.82 | 67 | — | — | — |
| + Year of birth | 88.839 | 66 | 21.98 | 1 | 0.001 |
| + District | 67.955 | 63 | 20.88 | 3 | 0.001 |
| + Interaction | 64.747 | 60 | 3.208 | 3 | 0.361 |
| Spina bifida and cranium bifidum | |||||
| Constant prevalence | 70.914 | 67 | — | — | — |
| + Year of birth | 63.843 | 66 | 7.071 | 1 | 0.007 |
| + District | 55.193 | 63 | 8.650 | 3 | 0.034 |
| + Interaction | 54.938 | 60 | 0.255 | 3 | 0.968 |
| Cardiovascular | |||||
| Constant prevalence | 83.093 | 67 | — | — | — |
| + Year of birth | 82.752 | 66 | 0.342 | 1 | 0.558 |
| + District | 76.430 | 63 | 6.322 | 3 | 0.096 |
| + Interaction | 74.400 | 60 | 2.030 | 3 | 0.566 |
| Urinary tract malformations | |||||
| Constant prevalence | 80.953 | 67 | — | — | — |
| + Year of birth | 74.179 | 66 | 6.774 | 1 | 0.009 |
| + District | 69.660 | 63 | 4.519 | 3 | 0.211 |
| + Interaction | 68.326 | 60 | 1.334 | 3 | 0.721 |
| Alimentary tract malformations | |||||
| Constant prevalence | 72.635 | 67 | — | — | — |
| + Year of birth | 72.276 | 66 | 0.358 | 1 | 0.549 |
| + District | 70.788 | 63 | 1.488 | 3 | 0.685 |
| + Interaction | 69.771 | 60 | 1.016 | 3 | 0.797 |
df = degrees of freedom.