Multiple Logistic Regression Analysis: Odds Ratios of Confounders with Severe Laceration.
| Variable | Project Without Instruments in Model Odds Ratio (CI) | Project with Instruments in Model Odds Ratio (CI) |
|---|---|---|
| Epidural analgesia | 1.528 (1.092–2.137) | 1.287 (0.907–1.826) |
| Induced labor | 1.486 (1.077–2.051) | 1.411 (1.018–1.956) |
| Nulliparous | 3.904 (2.771–5.501) | 3.468 (2.447–4.915) |
| Any instrument | —* | 3.245 (2.162–4.869) |
| Birth weight (>4 kg) | 2.355 (1.465–3.788) | 2.194 (1.353–3.556) |
| Maternal age | t Test procedure eliminated correlation | t Test procedure eliminated correlation |
CI = confidence interval.
* Not included in model.
Note: Episiotomies were controlled for in this model.