Odds ratios for preterm birth: univariate and multivariate models
| Continuous variables | Univariate model (95% CI) | Multivariate model (95% CI) |
|---|---|---|
| Infant gender | ||
| Male | 1.13 (1.11 to 1.15) | 1.13 (1.11 to 1.15) |
| Female | 1.00 | 1.00 |
| Maternal age | ||
| <20 years | 1.55 (1.50 to 1.60) | 1.28 (1.24 to 1.33) |
| 20–24 years | 1.16 (1.13 to 1.19) | 1.07 (1.04 to 1.10) |
| 25–29 years | 1.00 (0.98 to 1.03) | 0.98 (0.95 to 1.00) |
| 30–34 years | 1.00 | 1.00 |
| 35+ years | 1.23 (1.19 to 1.27) | 1.21 (1.17 to 1.25) |
| Parity | ||
| 0 | 1.47 (1.44 to 1.50) | 1.40 (1.37 to 1.43) |
| 1 | 1.00 | 1.00 |
| 2 | 0.94 (0.91 to 0.97) | 0.94 (0.91 to 0.97) |
| 3 | 1.02 (0.97 to 1.07) | 1.01 (0.96 to 1.05) |
| 4+ | 1.22 (1.16 to 1.29) | 1.14 (1.0 to ,1.21) |
| Continuous variables | Beta (95% CI) | Beta (95% CI) |
| Year of birth | 1.018 (1.016 to 1.019) | 1.016 (1.015 to 1.018) |
| Deprivation Index decile | 1.029 (1.026 to 1.033) | 1.022 (1.019 to 1.026) |