The Volume-Outcome Relationship in Retroperitoneal Soft Tissue Sarcoma: Evidence of Improved Short- and Long-Term Outcomes at High-Volume Institutions

Table 5

Cox regression model for overall survival: all patients.

Variable	95% Wald
	Odds ratio	Confidence limits		value
Age	1.02	1.02	1.03	<0.0001
Female (reference = male)	0.79	0.72	0.87	<0.0001
Race (reference = white)
Black	0.81	0.69	0.96	0.015
Other	0.88	0.71	1.09	0.23
Insurance (reference = private)
Medicaid	1.38	1.11	1.70	0.0034
Medicare	1.14	1.00	1.30	0.056
No insured	1.38	1.07	1.79	0.014
Other government	1.18	0.75	1.86	0.47
Unknown	1.23	0.85	1.78	0.28
No high school degree (reference ≥ 29%)
<14%	0.77	0.67	0.90	0.0007
14–19.9%	0.86	0.73	1.00	0.055
20–28.9%	0.92	0.79	1.08	0.30
Charlson–Deyo (reference = 2)
0	0.72	0.58	0.88	0.0011
1	0.81	0.65	1.01	0.055
Tumor size (reference = <5 cm)
5–10 cm	1.02	0.83	1.25	0.85
>10 cm	1.43	1.19	1.73	0.0001
Grade (reference = grade 3)
Grade 1	0.34	0.28	0.40	<0.0001
Grade 2	0.52	0.44	0.61	<0.0001
Unknown	0.64	0.56	0.73	<0.0001
Margins (reference = R0)
R1	1.31	1.15	1.49	<0.0001
R2	2.18	1.73	2.75	<0.0001
Unknown	1.61	1.44	1.80	<0.0001
Surgery (reference = yes)
No	0.93	0.83	1.04	0.21
Radiation (reference = yes)
No	0.80	0.72	0.90	<0.0001
Chemotherapy (reference = yes)
No	1.26	1.11	1.42	0.0004
Hospital volume (reference = high)
Medium	1.44	0.98	2.10	0.064
Low	1.57	1.16	2.11	0.0032