Parameter estimate (%) and 95% CI | P value | |

Primary analyses | ||

Indicator 1—unsatisfactory newborn screening samples | ||

Intercept (baseline rate) | 2.25 (1.27 to 3.23) | 0.004 |

Preintervention slope (per quarter) | 0.00 (−0.13 to 0.14) | 0.97 |

Change in level after intervention | −0.68 (−2.29 to 1.22) | 0.49 |

Change in slope (per quarter) after intervention | 0.10 (−0.18 to 0.38) | 0.50 |

Postintervention slope (preintervention slope plus change in slope) | 0.10 (−0.40 to 0.60) | 0.71 |

Indicator 2—episiotomy | ||

Intercept (baseline rate) | 12.68 (12.36 to 13.00) | <0.001 |

Preintervention slope (per month) | −0.03 (−0.05 to −0.02) | <0.001 |

Change in level after intervention | −0.85 (−1.51 to −0.19) | 0.01 |

Change in slope (per month) after intervention | −0.02 (−0.06 to 0.01) | 0.20 |

Postintervention slope (preintervention slope plus change in slope) | −0.05 (−0.09 to −0.02) | <0.001 |

Indicator 3—formula supplementation | ||

Intercept (baseline rate) | 33.48 (33.15 to 33.82) | <0.001 |

Preintervention slope (per month) | −0.08 (−0.09 to −0.06) | <0.001 |

Change in level after intervention | 2.02 (1.29 to 2.74) | <0.001 |

Change in slope (per month) after intervention | −0.07 (−0.11 to −0.02) | 0.004 |

Postintervention slope (preintervention slope plus change in slope) | −0.14 (−0.18 to −0.10) | <0.001 |

Indicator 4—elective repeat caesarean delivery prior to 39 weeks | ||

Intercept (baseline rate) | 58.31 (57.92 to 58.70) | <0.001 |

Preintervention slope (per month) | −0.21 (−0.23 to −0.19) | <0.001 |

Change in level after intervention | −5.30 (−6.17 to −4.43) | <0.001 |

Change in slope (per month) after intervention | −0.17 (−0.22 to −0.12) | <0.001 |

Postintervention slope (preintervention slope plus change in slope) | −0.38 (−0.46 to −0.34) | <0.001 |

Indicator 5—GBS screening | ||

Intercept (baseline rate) | 92.91 (92.66 to 93.15) | <0.001 |

Preintervention slope (per month) | 0.02 (0.00 to 0.03) | 0.007 |

Change in level after intervention | −0.40 (−0.91 to 0.12) | 0.13 |

Change in slope (per month) after intervention | 0.11 (0.08 to 0.14) | <0.001 |

Postintervention slope (preintervention slope plus change in slope) | 0.12 (0.10 to 0.15) | <0.001 |

Indicator 6—postdates induction prior to 41 weeks | ||

Intercept (baseline rate) | 21.55 (19.90 to 23.20) | <0.001 |

Preintervention slope (per month) | 0.09 (0.01 to 0.17) | 0.02 |

Change in level after intervention | 0.36 (−3.69 to 4.41) | 0.85 |

Change in slope (per month) after intervention | −0.40 (−0.59 to −0.21) | <0.001 |

Postintervention slope (preintervention slope plus change in slope) | −0.31 (−0.50 to −0.12) | 0.002 |

Control analyses | ||

Internal control outcome 1—caesarean in induced nulliparous women | ||

Intercept (baseline rate) | 30.08 (29.46 to 30.70) | <0.001 |

Preintervention slope (per month) | 0.04 (0.01 to 0.07) | 0.01 |

Change in level after intervention | −0.90 (−2.11 to 0.31) | 0.15 |

Change in slope (per month) after intervention | 0.02 (−0.04 to 0.09) | 0.47 |

Postintervention slope (preintervention slope plus change in slope) | 0.07 (0.01 to 0.12) | 0.03 |

Internal control outcome 2—use of auscultation | ||

Intercept (baseline rate) | 39.50 (37.39 to 41.60) | <0.001 |

Preintervention slope (per month) | 0.23 (0.13 to 0.34) | <0.001 |

Change in level after intervention | 5.91 (0.48 to 11.34) | 0.01 |

Change in slope (per month) after intervention | −0.29 (−0.05 to −0.04) | 0.01 |

Postintervention slope (preintervention slope plus change in slope) | −0.06 (−0.31 to 0.19) | 0.65 |

External control indicators (British Columbia data set) | ||

Indicator 2—episiotomy | ||

Intercept (baseline rate) | 6.12 (5.92 to 6.32) | <0.001 |

Preintervention slope (per month) | −0.03 (−0.04 to −0.01) | <0.001 |

Change in level after intervention | 0.09 (−0.37 to 0.56) | 0.67 |

Change in slope (per month) after intervention | 0.02 (0.00 to 0.05) | 0.08 |

Postintervention slope (preintervention slope plus change in slope) | −0.01 (−0.03 to 0.02) | 0.69 |

Indicator 4—elective repeat caesarean delivery prior to 39 weeks | ||

Intercept (baseline rate) | 50.17 (47.18 to 53.17) | <0.001 |

Preintervention slope (per month) | −0.18 (−0.35 to −0.02) | 0.01 |

Change in level after intervention | 4.60 (−1.37 to 10.57) | 0.11 |

Change in slope (per month) after intervention | −0.23 (−0.06 to 0.10) | 0.13 |

Postintervention slope (preintervention slope plus change in slope) | −0.41 (−0.69 to −0.13) | 0.004 |

Indicator 5—GBS screening | ||

Intercept (baseline rate) | 92.84 (92.57 to 93.11) | <0.001 |

Preintervention slope (per month) | 0.00 (−0.01 to 0.02) | 0.49 |

Change in level after intervention | 0.90 (0.33 to 1.47) | 0.002 |

Change in slope (per month) after intervention | −0.02 (−0.05 to 0.01) | 0.17 |

Postintervention slope (preintervention slope plus change in slope) | −0.02 (−0.05 to 0.02) | 0.25 |

Indicator 6—postdates induction prior to 41 weeks | ||

Intercept (baseline rate) | 16.33 (16.08 to 16.59) | <0.001 |

Preintervention slope (per month) | −0.07 (−0.08 to −0.06) | <0.001 |

Change in level after intervention | 0.47 (−0.19 to 1.22) | 0.15 |

Change in slope (per month) after intervention | 0.09 (0.06 to 0.13) | <0.001 |

Postintervention slope (preintervention slope plus change in slope) | 0.02 (−0.01 to 0.05) | 0.21 |

GBS, group B streptococcus.