Logistic regression model for the risk-adjusted VLAD and CUSUM
| Variable | OR | 95% CI | P value |
| Birth weight (Kg) | 0.34 | (0.23 to 0.51) | <0.001 |
| Pregnancy complications | 3.8 | (1.1 to 12.9) | 0.003 |
| Fetal heart rate | <0.001 | ||
| Normal | 1 | Reference | |
| Abnormal | 34.6 | (19.8 to 60.3) | <0.001 |
| Not detectable | 1289 | (419 to 3966) | <0.001 |
| Not measured | 5.6 | (1.6 to 19.6) | 0.007 |
| Presentation | <0.001 | ||
| Cephalic | 1 | Reference | |
| Breech | 2.4 | (1.02 to 5.57) | 0.045 |
| Shoulder dystocia | 0.33 | (0.002 to 45) | 0.66 |
| Transverse | 8.0 | (2.4 to 27) | <0.001 |
| Others | 1.5 | (0.46 to 4.9) | 0.50 |
CUSUM, cumulative sum; VLAD, variable life adjusted display.