Table 3.
Average yearly rate of change in the occurrence rate of neural tube defects in study areas
|
Incidence rate ratio†(95% CI)
|
|||||
|---|---|---|---|---|---|
| Registry area* | Period | Births | Total neural tube defects | Spina bifida | Anencephaly |
| Norway | 1988-98 | 662 441 | 1.01 (0.98 to 1.04) | 1.01 (0.97 to 1.04) | 1.01 (0.96 to 1.06) |
| Finland | 1988-98 | 697 687 | 1.02 (0.99 to 1.05) | 1.03 (1.00 to 1.07) | 1.00 (0.96 to 1.04) |
| Northern Netherlands (↓) | 1988-98 | 205 653 | 0.93 (0.88 to 0.97) | 0.90 (0.85 to 0.96) | 0.98 (0.90 to 1.07) |
| England and Wales (↓) | 1988-98 | 7 424 798 | 0.98 (0.97 to 0.98) | 0.97 (0.96 to 0.98) | 0.98 (0.97 to 1.00) |
| Ireland (↓) | 1988-98 | 209 997 | 0.91 (0.87 to 0.95) | 0.93 (0.88 to 0.98) | 0.89 (0.83 to 0.94) |
| France, Paris | 1988-98 | 406 140 | 1.01 (0.98 to 1.04) | 1.01 (0.97 to 1.06) | 1.00 (0.96 to 1.04) |
| France, Strasbourg | 1988-97 | 134 063 | 1.03 (0.97 to 1.10) | 1.07 (0.97 to 1.17) | 1.00 (0.92 to 1.09) |
| France, Central East | 1988-98 | 1 118 707 | 1.02 (0.99 to 1.04) | 1.03 (1.00 to 1.06) | 0.99 (0.95 to 1.03) |
| Hungary (↓) | 1988-98 | 1 275 779 | 0.94 (0.91 to 0.96) | 0.92 (0.89 to 0.95) | 0.99 (0.94 to 1.04) |
| Italy, Emilia Romagna | 1988-98 | 271 494 | 1.02 (0.95 to 1.08) | 0.96 (0.90 to 1.04) | 1.37 (1.12 to 1.66) |
| Italy, Campania | 1991-8 | 351 166 | 1.00 (0.94 to 1.06) | 1.00 (0.93 to 1.08) | 1.00 (0.92 to 1.08) |
| Portugal | 1991-8 | 79 249 | 0.96 (0.85 to 1.08) | 0.97 (0.83 to 1.12) | 0.94 (0.76 to 1.17) |
| Israel | 1988-98 | 188 328 | 1.00 (0.88 to 1.13) | 1.01 (0.86 to 1.19) | 0.98 (0.81 to 1.19) |
| Total | 13 025 502 | ||||
*
Arrow indicates areas with a decrease, on average, in rates of neural tube defects during the study period.
†
Can be interpreted as average change in rate per year (<1 indicates decreasing rates; >1 indicates increasing rates).