APPENDIX TABLE 1.

Estimation Results From Alternative Models on Trauma Center Closures Between 1990 to 2005

	Model 2 (Include Early Adopter Indicator)		Model 3 (Cox Proportional Hazard)		Model 4 (Exclude Profit Margin)		Model 5 (Standard SE)
	Hazard Ratio	P	Hazard Ratio	P	Hazard Ratio	P	Hazard Ratio	P
Financial pressure measures
Profit margin
Hospital with (−5, 5)% margin	1.000	—	1.000		—		1.000	—
Hospital with < − 5% profit margin	1.295*	0.07	1.391†	0.01	—	—	1.384†	0.00
Hospital with >5% profit margin	0.971	0.85	1.048	0.73	—	—	1.010	0.88
Medicare payment generosity
Receive average reimbursement	1.000	—	1.000	—	—	—	1.000	—
Received less generous Medicare reimbursement than average	0.984	0.92	1.021	0.89	1.002	0.99	1.024	0.72
Received more generous Medicare reimbursement than average	0.555†	0.01	0.629†	0.02	0.614‡	0.03	0.578†	0.00
Medicaid payment generosity
Hospitals in states with average Medicaid physician payment	1.000		1.000	—	—	—	1.000	—
Hospitals in states with below average Medicaid physician payment	1.439*	0.05	1.127	0.50	1.231	0.25	1.237†	0.00
Hospitals in states with above average Medicaid physician payment	0.998	0.99	0.935	0.64	0.928	0.62	0.939	0.33
HMO penetration level
Low HMO markets	1.000		1.000	—	—	—	1.000	—
Medium HMO markets	1.581†	0.01	1.618†	0.00	1.622†	0.00	1.628†	0.00
High HMO markets	1.953†	0.00	2.012†	0.00	2.064†	0.00	2.059†	0.00
County population characteristics
Minority population
Low share (lower 1/3)	1.000	—	1.000	—	—	—	1.000	—
Medium share	1.176	0.34	1.226	0.19	1.218	0.24	1.213†	0.01
High share	1.587†	0.01	1.694†	0.00	1.693†	0.01	1.693†	0.00
Population under poverty line
Low share (lower 1/3)	1.000	—	1.000	—	—	—	1.000	—
Medium share	1.058	0.75	1.078	0.63	1.059	0.74	1.048	0.51
High share	1.339	0.20	1.303	0.20	1.352	0.18	1.352†	0.00
Elderly population
Low share (lower 1/3)	1.000	—	1.000	—	—	—	1.000	—
Medium share	1.134	0.43	1.124	0.43	1.129	0.44	1.122*	0.08
High share	1.321	0.11	1.321*	0.08	1.305	0.13	1.278†	0.00
Uninsured population in 2000
15% or lower	1.000	—	1.000	—	—	—	1.000	—
Greater than 15%	0.933	0.68	0.908	0.55	0.902	0.54	0.908	0.18
Other population characteristics
Population (log transformed)	1.015	0.84	1.028	0.70	1.038	0.61	1.034	0.29
Cost of living (log transformed)	1.199	0.78	0.696	0.53	0.616	0.43	0.656	0.10
Hospital characteristics
For-profit hospital	1.846†	0.00	1.895†	0.00	1.944†	0.00	1.975†	0.00
Government hospital	0.847	0.42	0.876	0.50	0.892	0.57	0.856*	0.07
Teaching hospital	0.502†	0.00	0.417†	0.00	0.438†	0.00	0.444†	0.00
Member of a system	1.261*	0.09	1.250*	0.07	1.271*	0.07	1.276†	0.00
Case-mix index (log transformed)	0.132†	0.00	0.114†	0.00	0.097†	0.00	0.108	0.00
Total visits to ED (log transformed)	0.846†	0.00	0.856†	0.00	0.844†	0.00	0.848†	0.00
Hospital market characteristics
Presence of another trauma center within 15-mile radius	0.857	0.29	0.807	0.11	0.849	0.26	0.833†	0.00
Share of Medicaid discharges twice as much as the average competitor within 15-mile radius	0.810	0.37	0.854	0.44	0.882	0.59	0.840*	0.09
Competitive hospital market (hospital Herfindahl index <0.25)	0.765	0.13	0.734*	0.06	0.720*	0.06	0.703†	0.00
Percent for-profit hospitals within 15-mile radius	1.055	0.90	1.103	0.79	1.066	0.88	1.092	0.59
Percent government hospitals within 15-mile radius	1.634	0.31	1.512	0.37	1.594	0.33	1.561†	0.03
Early adopter indicator
= 1 if provide trauma center service since 1990	0.485†	0.00	—	—	—	—		—
Observations	—	9555	—	9555	—	9555	—	9555

^*Significant at 1%;

^†significant at 10%;

^‡significant at 5%.

Census region and year indicators are included.