From: Association between intimate partner violence during pregnancy and risk of preterm birth
 | Before matching | After matching | ||||||
---|---|---|---|---|---|---|---|---|
IPV | No IPV | p-value | %bias | IPV | No IPV | p-value | %bias | |
Age (Years) | ||||||||
 20–24 | 14.6 | 22.8 | 0.05 | −21.1 | 14.6 | 17.3 | 0.596 | −7 |
 25–29 | 24.3 | 26.4 | 0.635 | −4.8 | 24.3 | 25.0 | 0.898 | −1.8 |
 30–34 | 24.3 | 24.1 | 0.968 | 0.4 | 24.3 | 21.2 | 0.597 | 7.2 |
 35–39 | 20.4 | 13.4 | 0.041 | 18.7 | 20.4 | 20.8 | 0.945 | −1 |
 40–44 | 6.8 | 6.4 | 0.884 | 1.4 | 6.8 | 6.2 | 0.866 | 2.3 |
 45–49 | 2.9 | 1.2 | 0.135 | 11.8 | 2.9 | 2.5 | 0.865 | 2.7 |
Level of Education | ||||||||
 Primary | 26.2 | 28.7 | 0.578 | −5.6 | 26.2 | 20.6 | 0.342 | 12.6 |
 Secondary plus | 73.8 | 71.3 | 0.578 | 5.6 | 73.8 | 79.4 | 0.342 | −12.6 |
Husbands’ level of education | ||||||||
 Primary | 17.5 | 19.8 | 0.565 | −5.9 | 17.5 | 16.3 | 0.824 | 3 |
 Secondary plus | 81.6 | 79.1 | 0.546 | 6.1 | 81.6 | 83.1 | 0.771 | −3.9 |
Wealth Index | ||||||||
 Middle | 11.7 | 15.4 | 0.297 | −11 | 11.7 | 14.0 | 0.619 | −6.8 |
 Rich | 63.1 | 47.5 | 0.002 | 31.7 | 63.1 | 62.7 | 0.954 | 0.8 |
Work status | ||||||||
 Not working | 51.5 | 49.3 | 0.67 | 4.2 | 51.5 | 53.0 | 0.824 | −3.1 |
Residence | ||||||||
 Urban | 43.7 | 61.6 | 0 | −36.4 | 43.7 | 41.7 | 0.779 | 3.9 |
Smoke | ||||||||
 Cigarette smoking | 1.0 | 0.1 | 0.032 | 11.3 | 1.0 | 1.2 | 0.893 | −2.6 |
Age at first intercourse | ||||||||
 15–17 | 33.0 | 39.9 | 0.156 | −14.4 | 33.0 | 30.7 | 0.721 | 4.8 |
 18+ | 63.1 | 54.8 | 0.093 | 17 | 63.1 | 66.4 | 0.622 | −6.7 |
Prenatal Care | 93.2 | 94.5 | 0.577 | −5.3 | 93.2 | 93.8 | 0.866 | −2.4 |
Number of antenatal visits | ||||||||
 4–7 times | 34.0 | 48.4 | 0.004 | −29.5 | 34.0 | 36.5 | 0.706 | −5.2 |
 8–20 times | 16.5 | 12.5 | 0.228 | 11.3 | 16.5 | 14.8 | 0.731 | 5 |
Wanted pregnancy | 62.1 | 68.9 | 0.143 | −14.2 | 62.1 | 61.9 | 0.977 | 0.4 |