Table 2.

Adjusted odds ratio and 80% interval odds ratio of patient and hospital-level factors on vaginal birth after cesarean

Factors	Odds Ratio (95% CI)	P-value	80% Interval OR1
Maternal age, years	0.98 (0.97-0.99)	<0.001
Obesity	0.58 (0.41-0.84)	0.003
Diabetes2	0.65 (0.52-0.81)	<0.001
Chronic hypertension	0.42 (0.28-0.64)	<0.001
Pre-eclampsia	0.50 (0.32-0.78)	0.002
Gestational hypertension	0.52 (0.35-0.78)	0.002
Large for gestational age	0.32 (0.18-0.55)	<0.001
Annual delivery volume (quartile)
1st (281-534 births)	reference	reference	reference
2nd (549-995 births)	2.75 (1.23-6.17)	0.02	0.92-8.17
3rd (996-1975 births)	3.73 (1.59-8.75)	0.003	1.25-11.07
4th (1989-7657 births)	2.92 (1.11-7.72)	0.03	0.98-8.69
Level of obstetric care3
Level 1	reference	reference	reference
Level 2	1.02 (0.55-1.92)	0.08	0.34-3.04
Level 3	1.07 (0.51-2.23)	0.18	0.36-3.17
Neonatal intensive care	1.95 (0.89-4.27)	0.09	0.66-5.80
Neonatal intermediate care	1.60 (0.92-2.77)	0.09	0.54-4.75

C-statistic 0.67 for the hierarchical multivariable model

CI, confidence interval; OR, odds ratio

¹80% interval OR only computed for hospital-level factors to assess effect on variation in vaginal birth after cesarean

²Gestational and pre-existing diabetes

³Level 1 “provides services for uncomplicated maternity and newborn cases”; Level 2 “provides service for all uncomplicated and most complicated cases”; Level 3 “provides services for all serious illnesses and abnormalities