Table 5. Multiple logistic regression analysis to determine factors associated with methotrexate treatment success (N=73).

Yolk sac, cardiac activities, and history of previous abortion were included for variable selection using the backward likelihood ratio (LR) variable selection method. Only cardiac activities are retained in the preliminary main effect model.

Assessment of model fitness: Classification table overall percentage of correct prediction = 87.5%; Area under ROC curve = 76.1% (95% CI: 56.3, 96.0).

Characteristic	Crude OR (95% CI)	P-value	Adjusted OR (95% CI)	P-value
Fetal cardiac activities
Absent	10.20 (1.93, 53.79)	0.006	-	-
Present	Ref