Table 2 Prediction model for probability of successful induction of labour
Variable | β-Coefficient | Standard Error | p Value | |
|---|---|---|---|---|
(Intercept) | 0.82 | 0.10 | < 0.001 | |
a | Parity (Multiparous) | 1.79 | 0.22 | < 0.001 |
b | Weight, pre-pregnancy (kg) | 61.21 | 11.84 | < 0.001 |
(Weight, pre-pregnancy)2 | −12.45 | 7.35 | 0.09 | |
(Weight, pre-pregnancy)3 | −6.48 | 5.07 | 0.20 | |
c | BMI, pre-pregnancy (kg/m2) | −57.98 | 8.56 | < 0.001 |
(BMI, pre-pregnancy)2 | 9.42 | 5.90 | 0.11 | |
(BMI, pre-pregnancy)3 | 12.68 | 5.04 | 0.01 | |
d | Gestational Age (weeks) | −6.01 | 2.66 | 0.02 |
(Gestational Age)2 | −3.41 | 2.49 | 0.17 | |
(Gestational Age)3 | 4.52 | 2.47 | 0.07 | |
e | Weight, at-delivery (kg) | −13.97 | 7.62 | 0.07 |
(Weight, at-delivery)2 | 7.79 | 4.90 | 0.11 | |
f | Dilation (cm) | 23.57 | 3.98 | < 0.001 |
(Dilation)2 | 4.97 | 3.87 | 0.20 | |
g | Maternal Age (years) | −8.43 | 2.57 | < 0.001 |
(Maternal Age)2 | −4.35 | 2.34 | 0.06 | |
Equation | Risk Score = 0.82 + [1.79 x a] + [61.21 x b] - [12.45 x b2] - [6.48 x b3] - [57.98 x c] + [9.42 x c2] + [12.68 x c3] - [6.01 x d] - [3.41 x d2] + [4.52 x d3] - [13.97 x e] + [7.79 x e2] + [23.57 x f] + [4.97 x f2] – [8.43 x g] – [4.35 x g2]; probability of vaginal delivery = 1/(1 + e-Risk Score) | |||
Model Performance | Hosmer-Lemeshow goodness-of-fit χ2 = 5.02, 8 degrees of freedom, p = 0.76 Area under receiver operating characteristic curve 0.81 [95% CI 0.78–0.83] | |||