Table 3.

Cox proportional hazards model for predicting IUP and recurrence of EP after medical treatment with MTX or surgical treatment with salpingostomy or salpingectomy

	IUP		Recurrence of EP
	Hazard ratio (95% CI)	p-value	Hazard ratio (95% CI)	p-value
Age (yr)	0.99 (1.06 -0.93)	0.483	1.04 (0.93-1.16)	0.483
Body mass index (kg/m ${}^2$ )	0.97 (0.89-1.07)	0.831	1.02 (0.85-1.24)	0.831
Pelvic inflammatory disease ${}^{*}$	0.83 (0.11-6.12)	0.853	0.047 (0.0-NE)	0.754
Endometriosis ${}^{*}$	0.93 (0.22-3.95)	0.992	0.045 (0.0-NE)	0.653
Cesarean section ${}^{*}$	2.07 (0.99-4.32)	0.052	1.56 (0.35-6.99)	0.564
EP ${}^{*}$	0.7 (0.21-2.30)	0.535	2.89 (0.55-15.13)	0.208
Parity	1.37 (1.06-1.77)	0.015	1.61 (1.02-2.53)	0.039
Live birth	1.54 (1.01-2.37)	0.049	3.84 (1.43-10.98)	0.012
Miscarriage ${}^{*}$	2.37 (1.01-5.56)	0.047	0.30 (0.06-1.53)	0.147
Therapeutic modality
Salpingectomy ${}^{\#}$	0.67 (0.28-1.56)	0.363	0.76 (0.13-4.59)	0.886
Salpingostomy ${}^{\#}$	0.81 (0.32-2.03)	0.653	0.92 (0.15-5.54)	0.452
${}^{*}$ Reference is the subject without a history. ${}^{\#}$ Reference is the subject treated with MTX. EP: Ectopic pregnancy, IUP: Intrauterine pregnancy, CI: Confidence interval, NE: Not estimable