Risk ratio for RA according to breastfeeding and reproductive factors
| Characteristics | B | Odds ratio | 95% Confidence interval | p-value |
|---|---|---|---|---|
| Breast-feeding | ||||
| Ever breastfed | −1.557 | 0.211 | 0.127–0.349 | <0.001 |
| Duration of breastfeeding (months) | −0.010 | 0.990 | 0.986–0.995 | <0.001 |
| Parity (number of liver births) | 0.016 | 1.016 | 0.897–1.151 | 0.253 |
| Use of oral contraceptives | −0.151 | 0.860 | 0.624–1.186 | 0.357 |
| Use of postmenopausal hormones | −0.119 | 0.888 | 0.601–1.312 | 0.551 |
| Waist circumference | −0.146 | 0.864 | 0.536–1.392 | 0.549 |