Table 2.

Unadjusted and adjusted risk of death using Cox regression

Cox regression model for OS	Hazard ratio (95 % CI)	p value
Unadjusted analysis
Post-2004 versus Pre-2004	0.7 (0.5–1.1)	0.10
Age	1.1 (1.0–1.1)	<0.001
Gender: male versus female	1.3 (0.9–1.9)	0.10
Race
Black versus white	1.1 (0.6–2.1)	0.70
Other versus white	0.4 (0.2–1.1)	0.08
Black versus other	2.8 (0.9–8.6)	0.08
KPS ≤ 60 versus > 60	4.9 (3.2–7.7)	<0.0001
Surgery
Biopsy versus GTR	4.9 (3.0–7.9)	<0.0001
STR versus GTR	1.9 (0.1–0.3)	0.007
Adjusted analysis
Post-2004 versus Pre-2004	0.6 (0.4–0.9)	0.0145
Age	1.0 (1.0–1.1)	0.0001
KPS <=60 versus > 60	4.2 (2.6–6.7)	0.0001
Biopsy versus GTR	3.5 (2.1–5.9)	0.0001
Subtotal resection versus GTR	1.6 (1.0–2.7)	0.046

KPS Karnofsky performance status, STR subtotal resection, GTR gross total resection