Table 3.

Unweighted multivariate analyses of OS and CSS.

Covariable	OS		CSS
	HR (95%CI)	P	HR (95%CI)	P
Age (<65 as ref.)
≥65	1.86 (1.53–2.26)	<0.001	1.81 (1.44–2.27)	<0.001
Gender (male as ref.)
Female	0.83 (0.68–1.02)	0.079	0.77 (0.60–0.98)	0.034
Race (whites as ref.)
Black	0.94 (0.73–1.22)	0.65	0.77 (0.57–1.05)	0.102
Other	0.89 (0.73–1.08)	0.23	0.88 (0.71–1.10)	0.265
Year of diagnosis (1988–2003 as ref.)
2004–2012	0.64 (0.53–0.77)	<0.001	0.67 (0.54–0.83)	<0.001
Histology (squamous cell as ref.)
Non-keratinizing carcinoma/undifferentiated carcinoma	0.79 (0.64–0.98)	0.029	0.77 (0.61–0.96)	0.024
Surgery (no surgery as ref.)
Surgery	0.58 (0.43–0.78)	<0.001	0.56 (0.39–0.81)	0.002
Radiotherapy (no radiotherapy as ref.)
Radiotherapy	0.50 (0.42–0.61)	<0.001	0.50 (0.41–0.62)	<0.001