TABLE 3.
Risk ratios for labor interventions and birth outcomes among low-risk nulliparous women from the Consortium on Safe Labor receiving intrapartum care at interprofessional versus noninterprofessional medical centers, United States, 2002–2008: Results of logistic regression analyses
| Outcome | Unadjusted model (N = 14 375), RR (95% CI) | Adjusted modela (N = 14 375), =RR (95% CI) | Propensity score-adjusted model (N = 14 375), RR (95% CI) | Propensity score-matched model (N = 7042), RR (95% CI) |
|---|---|---|---|---|
| Gestational age | ||||
| Early term (37 0/7–38 6/7) | 0.69 (0.64–0.74)*** | 0.73 (0.67–0.79)*** | 0.73 (0.67–0.80)*** | 0.70 (0.63–0.78)*** |
| Full term (39 0/7–40 6/7) | Reference | Reference | Reference | Reference |
| Late term (41 0/7–41 6/7) | 1.65 (1.48–1.84)*** | 1.67 (1.47–1.90)*** | 1.68 (1.48–1.90)*** | 1.76 (1.50–2.07)*** |
| Postterm (≥ 42 0/7) | 2.04 (1.40–2.96)*** | 1.90 (1.25–2.88)** | 1.90 (1.25–2.89)** | 3.66 (1.82–7.36)*** |
| Type of labor | ||||
| Spontaneous onset and trial of labor | Reference | Reference | Reference | Reference |
| Induction and trial of labor | 0.26 (0.24–0.28)*** | 0.25 (0.23–0.27)*** | 0.26 (0.24–0.28)*** | 0.26 (0.24–0.29)*** |
| Cesarean without trial of labor | 0.31 (0.25–0.38)*** | 0.35 (0.28–0.43)*** | 0.37 (0.30–0.47)*** | 0.30 (0.22–0.41)*** |
| Rupture of membranes | ||||
| Spontaneous | Reference | Reference | Reference | Reference |
| Amniotomy | 0.83 (0.77–0.89)*** | 0.82 (0.76–0.89)*** | 0.83 (0.77–0.90)*** | 0.71 (0.64–0.78)*** |
| Oxytocin augmentationb | ||||
| Yes | 0.23 (0.21–0.26)*** | 0.26 (0.23–0.29)*** | 0.26 (0.24–0.29)*** | 0.25 (0.22–0.29)*** |
| No | Reference | Reference | Reference | Reference |
| Mode of birth | ||||
| Vaginal—spontaneous | Reference | Reference | Reference | Reference |
| Vaginal—assisted | 0.99 (0.89–1.11) | 1.00 (0.88–1.14) | 1.01 (0.88–1.14) | 0.93 (0.78–1.10) |
| Cesarean | 0.67 (0.62–0.72)*** | 0.86 (0.79–0.94)** | 0.87 (0.79–0.95)** | 0.88 (0.79–0.98)* |
| Neonatal intensive care unit admission | ||||
| Yes | 1.00 (0.86–1.17) | 1.11 (0.93–1.32) | 1.12 (0.94–1.34) | 1.29 (1.04–1.60)* |
| No | Reference | Reference | Reference | Reference |
Noninterprofessional centers (physician practitioners only) are the reference group
a
Adjusted for maternal age, race, and health insurance type.
b
Limited to women with spontaneous labor onset and a trial of labor.
*
P < 0.05
**
P < 0.01
***
P < 0.001.