Table 3.

Cox Proportional Hazards Model for Patient Overall Survival

Patient Characteristic	Adjusted HR (95% CI)	p value
Age at Diagnosis Race	1.023 (1.02-1.03)	<0.001
Non-Hispanic White	-	-
Non-Hispanic Black	1.55(1.39-1.72)	<0.001
Hispanic	0.87 (0.70-1.09)	0.23
Other	0.88 (0.66-1.17)	0.37
Primary Tumor Site
Base of Tongue	-	-
Tonsil	1.00 (0.93-1.09)	0.92
Pharyngeal Wall/ Soft Palate	1.70 (1.44-2.01)	<0.001
Oropharynx NOS	1.48 (1.29-1.70)	<0.001
Clinical Stage
III	-	-
IV	1.37 (1.26-1.50)	<0.001
Comorbidity Index
None	-	-
Moderate (1)	1.49 (1.34-1.66)	<0.001
High (2)	1.47 (1.17-1.84)	0.001
Year of Diagnosis
2003	-	-
2004	0.96 (0.86-1.07)	0.41
2005	1.04 (0.93-1.15)	0.51
2006	1.01 (0.90-1.13)	0.89
Radiation Technique
Non-IMRT	-	-
IMRT	0.75 (0.68-0.82)	<0.001
Treatment Facility
Community	-	-
Academic	1.01 (0.93-1.10)	0.82
Facility Case-Volume
Low Case-Volume	-	-
High Case-Volume	0.84 (0.76-0.93)	0.001
Geographic Region
Northeast	-	-
Southeast	0.99 (0.89-1.11)	0.91
Midwest	1.00 (0.90-1.11)	0.99
West	0.87 (0.76-0.99)	0.04
Insurance Status
Commercial Insurance	-	-
Medicare	1.74 (1.56-1.94)	<0.001
Medicaid	2.10 (1.86-2.37)	<0.001
Uninsured	2.05 (1.79-2.36)	<0.001
Government	1.69 (1.32-2.16)	<0.001
Unknown	1.80 (1.42-2.27)	<0.001
Diagnosis to Treatment Interval
DTI ≤ 30 days	-	-
DTI > 30 days	1.12 (1.03-1.20)	0.005
DTI (measured in weeks)	1.02 (1.01-1.03)	<0.001
DTI in Tertiles
DTI ≤ 3 weeks	-	-
DTI 3-6 weeks	1.15 (1.05-1.27)	0.003
DTI > 6 weeks	1.22 (1.10-1.35)	<0.001