Table 4.
Average yearly change in rates of neural tube defects, after and before 1992
|
Total neural tube defects
|
Spina bifida
|
Anencephaly
|
||||||
|---|---|---|---|---|---|---|---|---|
| Area | Period | Births | Cases | IRR*(95% CI) | Cases | IRR*(95% CI) | Cases | IRR*(95% CI) |
| Norway | 1993-8
|
360 906
|
277
|
1.00 (0.93 to 1.07)
|
169
|
1.04 (0.95 to 1.14)
|
108
|
0.94 (0.84 to 1.05)
|
| To 1992 (ref) | 301 535 | 223 | 1.02 (0.93 to 1.12) | 145 | 1.03 (0.92 to 1.16) | 78 | 1.01 (0.86 to 1.18) | |
| Finland | 1993-8
|
371 826
|
289
|
1.07 (1.00 to 1.15)
|
179
|
1.05 (0.97 to 1.15)
|
110
|
1.10 (0.99 to 1.23)
|
| To 1992 (ref) | 325 861 | 248 | 1.04 (0.96 to 1.14) | 134 | 1.04 (0.92 to 1.17) | 114 | 1.05 (0.92 to 1.19) | |
| Northern Netherlands | 1993-8
|
116 337
|
89
|
0.99 (0.87 to 1.11)
|
55
|
0.99 (0.85 to 1.15)
|
34
|
0.99 (0.81 to 1.20)
|
| To 1992 (ref) | 89 316 | 107 | 0.91 (0.79 to 1.04) | 83 | 0.97 (0.82 to 1.14) | 24 | 0.71 (0.52 to 0.97) | |
| England and Wales | 1993-8
|
3 934 009
|
2485
|
0.97 (0.95 to 0.99)
|
1249
|
0.97 (0.94 to 1.00)
|
1236
|
0.97 (0.94 to 1.01)
|
| To 1992 (ref) | 3 490 789 | 2484 | 0.96 (0.93 to 0.99) | 1317 | 0.96 (0.92 to 0.99) | 1167 | 0.96 (0.92 to 1.00) | |
| Ireland | 1993-8
|
113 719
|
99
|
0.92 (0.82 to 1.03)
|
59
|
0.92 (0.79 to 1.07)
|
40
|
0.92 (0.77 to 1.10)
|
| To 1992 (ref) | 96 278 | 141 | 0.91 (0.81 to 1.02) | 74 | 0.94 (0.80 to 1.10) | 67 | 0.87 (0.73 to 1.03) | |
| France, Strasbourg | 1993-7
|
65 737
|
58
|
1.01 (0.84 to 1.22)
|
29
|
1.09 (0.84 to 1.41)
|
29
|
0.95 (0.73 to 1.22)
|
| To 1992 (ref) | 68 326 | 56 | 1.16 (0.96 to 1.40) | 22 | 1.04 (0.78 to 1.40) | 34 | 1.25 (0.98 to 1.59) | |
| France, Paris | 1993-8
|
221 290
|
223
|
0.99 (0.92 to 1.07)
|
122
|
0.94 (0.85 to 1.05)
|
101
|
1.04 (0.93 to 1.17)
|
| To 1992 (ref) | 184 850 | 181 | 1.05 (0.95 to 1.17) | 85 | 0.99 (0.85 to 1.16) | 96 | 1.11 (0.96 to 1.28) | |
| France, Central East | 1993-8
|
609 089
|
384
|
0.95 (0.89 to 1.01)
|
261
|
0.98 (0.91 to 1.05)
|
123
|
0.88 (0.79 to 0.98)
|
| To 1992 (ref) | 509 618 | 273 | 1.04 (0.95 to 1.13) | 172 | 1.02 (0.92 to 1.14) | 101 | 1.07 (0.93 to 1.23) | |
| Hungary | 1993-8
|
650 371
|
244
|
1.04 (0.95 to 1.15)
|
174
|
1.03 (0.92 to 1.14)
|
70
|
1.13 (0.91 to 1.41)
|
| To 1992 (ref) | 625 408 | 367 | 0.87 (0.80 to 0.94) | 283 | 0.82 (0.75 to 0.90) | 84 | 1.12 (0.91 to 1.38) | |
| Italy, Emilia Romagna | 1993-8
|
151 604
|
55
|
1.10 (0.93 to 1.29)
|
39
|
1.00 (0.82 to 1.21)
|
16
|
1.40 (1.01 to 1.95)
|
| To 1992 (ref) | 119 890 | 45 | 1.09 (0.88 to 1.34) | 43 | 1.11 (0.90 to 1.37) | 2 | 0.75 (0.27 to 2.09) | |
| Italy, Campania | 1993-8
|
276 108
|
200
|
0.88 (0.81 to 0.96)
|
107
|
0.90 (0.80 to 1.00)
|
93
|
0.87 (0.77 to 0.98)
|
| To 1992 (ref) | 75 058 | 34 | 1.46 (0.74 to 2.90) | 20 | 1.90 (0.76 to 4.77) | 14 | 1.02 (0.36 to 2.92) | |
| Portugal | 1993-1998
|
68 234
|
41
|
1.00 (0.83 to 1.21)
|
29
|
0.95 (0.76 to 1.18)
|
12
|
1.15 (0.79 to 1.67)
|
| To 1992 (ref) | 11 015 | 9 | 0.49 (0.12 to 1.97) | 5 | 0.66 (0.11 to 3.92) | 4 | 0.33 (0.03 to 3.15) | |
| Israel | 1993-1998
|
103 924
|
13
|
1.15 (0.83 to 1.58)
|
8
|
1.07 (0.71 to 1.60)
|
5
|
1.29 (0.74 to 2.24)
|
| To 1992 (ref) | 84 404 | 11 | 0.82 (0.53 to 1.27) | 6 | 0.87 (0.49 to 1.56) | 5 | 0.75 (0.39 to 1.47) | |
*
Incidence rate ratio (IRR) estimates the average yearly change in rate (<1 indicates decreasing rates; >1 indicates increasing rates).