Table 3.

Unadjusted and Adjusted Odds Ratios of Obstetric Unit Closure by 2010 Characteristics of Sample Hospitals (N = 263)

	Unadjusted Odds Ratio (95% Confidence Interval)†	Adjusted Odds Ratio (95% Confidence Interval)‡
Hospital characteristics
Annual birth volume in 2010 (per 100)	0.28 (0.10, 0.75) **	0.10 (0.02, 0.43) ***
Square of birth volume in 2010 (per 100)	1.08 (1.02, 1.14) **	1.13 (1.04, 1.23) ***
System affiliation	0.46 (0.17, 1.26)	0.51 (0.16, 1.68)
Hospital ownership (ref. government/public)
Private	0.98 (0.36, 2.68)	3.84 (1.37, 10.77) **
Proportion of noncommercially insured§	1.01 (0.97, 1.05)	1.02 (0.98, 1.06)
FTE RN per 1,000 inpatient days	0.92 (0.70, 1.21)	1.06 (0.82, 1.35)
Market characteristics
Number of births (per 100) in closest hospital	0.98 (0.91, 1.05)	1.04 (0.98, 1.09)
County‐level characteristics
Number of OBGYNs doing patient care per 1,000 females 18–40 years old	0.33 (0.11, 0.95) **	0.54 (0.15, 1.35)
Number of FPs doing patient care per 10,000 people	0.64 (0.42, 0.98) *	0.62 (0.43, 0.90) *
Number of CNMs per 1,000 females 18–40 years old	1.24 (0.36, 4.24)	1.28 (0.64, 2.55)
Median family income in 2006–2010	0.94 (0.89, 0.99) *	0.92 (0.86, 0.99) *
Females 18–40 years in 2010	0.94 (0.83, 1.07)	1.01 (1.002, 1.03) *

†Each variable's unadjusted odds ratio was derived from an individual model.

‡Adjusted McFadden's R‐square, referring to the amount of variance in odds of closures predicted by this model, is 0.326.

§Percent of women giving births in a hospital who had either Medicaid as the primary payer or who were uninsured at the time of hospitalization.

*p < .05, **p < .01, ***p < .001. Bold indicates significant results at p < .05.