Secondary outcomes: subsequent pregnancies and registerable birth
| FNP | Usual care | Adjusted* parameter estimate (95% CI) | P value | Absolute risk difference (FNP-usual care) (95% CI) | |
| Subsequent pregnancy | N=753 | N=753 | |||
| No | 163 (21.7%) | 163 (21.7%) | Reference | ||
| Yes | 590 (78.4%) | 590 (78.4%) | 1.00† (0.79 to 1.28) | 0.984 | 0.0% (−4.2% to 4.2%) |
| Subsequent registerable birth | N=752 | N=749 | |||
| No | 276 (36.7%) | 266 (35.5%) | Reference | ||
| Yes | 476 (63.3%) | 483 (64.5%) | 0.95† (0.77 to 1.18) | 0.662 | −1.2% (−6.0% to 3.7%) |
| One birth | 326 (68.5) | 331 (68.5) | 0.95‡ (0.76 to 1.19) | 0.655 | |
| Two | 124 (26.1) | 121 (25.1) | 0.99‡ (0.73 to 1.34) | 0.955 | |
| Three births or more | 26 (5.5) | 31 (6.4) | 0.80‡ (0.46 to 1.39) | 0.435 | |
| Interbirth interval between first and second child (days) Median (25–75th centiles) | 1027 (590 to 1506.75) | 1065 (665 to 1538) | 0.99§ (0.88 to 1.13) | 0.938 |
Data are n (%), n/N (%) or median (25–75th centile) unless otherwise stated.
*FNP compared with usual care. Analysis adjusted for stratification (site), minimisation variables (gestational age, smoking status at recruitment, and first or preferred language).
†OR from logistic model.
‡Relative risk ratio from multinomial model.
§HR from Cox model.
FNP, family nurse partnership.