Table 3.

Univariate and multivariate analysis for all patients using Cox proportional hazards model.

	Univariate Analysis			Multivariate Analysis
	HR	(95% CI)	p-value	HR	(95% CI)	p-value
Age, years (continuous)	1.02	1.02–1.03	<0.001	1.02	1.01–1.02	<0.001
Sex
Male	1.00
Female	1.13	1.01–1.26	0.034
Race
White	1.00			1.00
Non-white	1.57	1.43–1.73	<0.001	1.42	1.24–1.61	<0.001
Year
2004–2006	1.00
2007–2009	1.02	0.92–1.12	0.761
2010–2012	0.88	0.79–0.98	0.021
Charlson/Deyo score
0	1.00			1.00
1	1.23	1.10–1.39	<0.001	1.14	0.98–1.33	0.094
≥2	1.43	1.17–1.75	<0.001	1.26	0.98–1.62	0.067
Insurance type
Private	1.00			1.00
Non-private/Unknown	2.05	1.88–2.24	<0.001	1.57	1.39–1.78	<0.001
Income
<$48,000	1.00
≥$48,000	0.79	0.73–0.86	<0.001
Location
Urban (≥250,000)	1.00
Non-urban (<250,000)	0.99	0.91–1.09	0.902
Facility
Non-academic	1.00
Academic	0.91	0.84–0.99	0.031
Facility volume
Non-high	1.00
High	0.89	0.81–0.98	0.021
Head and neck subsite
Oral cavity	1.00			1.00
Oropharynx	0.49	0.43–0.56	<0.001	0.56	0.47–0.67	<0.001
Hypopharynx	1.02	0.87–1.20	0.815	0.96	0.78–1.18	0.681
Larynx	1.00	0.85–1.17	0.974	0.89	0.72–1.10	0.273
HPV Status
Negative	1.00			1.00
Positive	0.40	0.29–0.54	<0.001	0.53	0.35–0.80	0.002
Unknown	0.97	0.79–1.19	0.783	0.96	0.74–1.24	0.769
Radiation dose (Gy) (continuous)	0.99	0.99–1.00	<0.001	0.99	0.99–1.00	<0.001
Tumor size (mm) (continuous)	1.01	1.01–1.01	<0.001	1.00	1.00–1.01	0.005
Treatment
Primary surgery	1.00			1.00
Primary CRT	1.44	1.31–1.58	<0.001	1.27	1.11–1.46	<0.001
T stage
0	1.00			1.00
1	0.81	0.68–0.96	0.016	0.83	0.66–1.06	0.134
2	1.06	0.91–1.23	0.480	0.91	0.74–1.13	0.397
3	1.56	1.34–1.82	<0.001	1.21	0.98–1.51	0.080
4	2.09	1.80–2.43	<0.001	1.42	1.14–1.76	0.002
IPTW hazard model Treatment
Primary surgery	1.00
Primary CRT	1.13	1.05–1.22	0.002