Table 3.
Best fit nonconditional logistic regression model for risk of being nonpregnant in embryo transfer recipients (ET). Only associated variables are shown, even though all variables and interactions were tested.
| Predictor | p | OR | 95% CI | Omnibus Likelihood Ratio Tests | |||
|---|---|---|---|---|---|---|---|
| Lower | Upper | χ² | DF | p | |||
| Intercept | 0.36 | 0.82 | 0.54 | 1.25 | 7.64 | 1 | 0.006 |
| Cow’s age | 0.01 | 1.06 | 1.02 | 1.11 | |||
| Embryo quality | |||||||
| 2 | 0.71 | 1.06 | 0.78 | 1.43 | 6.75 | 2 | 0.034 |
| 3 | 0.01 | 1.88 | 1.17 | 3.02 | |||
| Year of treatment | |||||||
| 2015 | <0.001 | 0.38 | 0.24 | 0.61 | 21.10 | 4 | <0.001 |
| 2016 | 0.00 | 0.52 | 0.34 | 0.81 | |||
| 2017 | <0.001 | 0.47 | 0.30 | 0.72 | |||
| 2018 | 0.07 | 0.67 | 0.44 | 1.03 | |||
Reference levels: Embryo quality 1; Year of treatment: 2014; Cow’s age: as a continuous variable from 2 years old. Degrees of freedom (DF).