Table 2.
Use of folic acid supplements during early pregnancy by the prevalence of neural tube defects, before (2002–2004) and after (2011–2012) a massive folic acid supplementation programme, Shanxi Province and Jiangsu Province, China
| High-prevalence population | Low-prevalence population | |||||||
|---|---|---|---|---|---|---|---|---|
| Before (n 562) | After (n 1042) | Before (n 692) | After (n 688) | |||||
| Variable | n | % | n | % | n | % | n | % |
| Folic acid supplements | 86 | 15·3 | 882 | 84·6* | 458 | 66·2 | 634 | 92·2*† |
| Supplementation before LMP | 25 | 30·1 | 379 | 43·1* | 203 | 46·2 | 299 | 47·1 |
| Supplementation adherence | ||||||||
| ≥8 d/10 d | 58 | 85·3 | 734 | 83·9 | 349 | 78·3 | 520 | 87·8*† |
| 5–7 d/10 d | 6 | 8·8 | 93 | 10·6 | 67 | 15·0 | 58 | 9·8 |
| ≤5 d/10 d | 4 | 5·9 | 48 | 5·5 | 30 | 6·7 | 14 | 2·4 |
| Total days of supplementation | ||||||||
| <60 d | 67 | 79·8 | 217 | 25·5* | 215 | 55·3 | 343 | 57·1*† |
| 60–120 d | 11 | 13·1 | 393 | 46·2 | 137 | 35·2 | 146 | 24·3 |
| ≥120 d | 6 | 7·1 | 240 | 28·2 | 37 | 9·5 | 112 | 18·6 |
LMP, last menstrual period.
Note: Some variables have missing data.
*P<0·05 before and after the programme in the same population.
†P<0·05 between the high- and low-prevalence groups after the programme.