Table 4.

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

	Univariate Analysis			Multivariate Analysis
	HR	(95% CI)	p-value	HR	(95% CI)	p-value
Age, years (continuous)	1.03	1.02–1.03	<0.001	1.02	1.01–1.03	<0.001
Sex
Male	1.00
Female	1.13	0.96–1.33	0.127
Race
White	1.00			1.00
Non-white	1.75	1.53–1.99	<0.001	1.54	1.28–1.84	<0.001
Year
2004–2006	1.00			1.00
2007–2009	0.99	0.87–1.13	0.894	0.91	0.77–1.08	0.260
2010–2012	0.87	0.76–1.01	0.074	0.74	0.59–0.93	0.010
Charlson/Deyo score
0	1.00
1	1.15	0.97–1.35	0.104
≥2	1.67	1.29–2.17	<0.001
Insurance type
Private	1.00			1.00
Non-private/Unknown	2.21	1.97–2.48	<0.001	1.93	1.64–2.27	<0.001
Income
<$48,000	1.00
≥$48,000	0.73	0.66–0.82	<0.001
Location
Urban (≥250,000)	1.00
Non-urban (<250,000)	1.03	0.91–1.17	0.604
Facility
Non-academic	1.00			1.00
Academic	0.89	0.79–0.99	0.032	0.84	0.73–0.98	0.022
Facility volume
Non-high	1.00
High	0.94	0.83–1.06	0.306
HPV status
Negative	1.00			1.00
Positive	0.46	0.32–0.68	<0.001	0.46	0.28–0.74	0.002
Unknown	0.92	0.69–1.22	0.554	0.62	0.42–0.92	0.017
Radiation dose (Gy) (continuous)	0.99	0.99–1.00	0.002	0.99	0.99–1.00	0.004
Tumor size (mm) (continuous)	1.01	1.01–1.02	<0.001	1.00	1.00–1.01	0.012
Treatment
Primary surgery	1.00			1.00
Primary CRT	1.62	1.43–1.84	<0.001	1.29	1.06–1.56	0.009
T stage
0	1.00			1.00
1	0.85	0.68–1.05	0.129	0.94	0.68–1.29	0.690
2	0.96	0.79–1.17	0.703	0.83	0.62–1.11	0.197
3	1.50	1.23–1.84	<0.001	1.17	0.87–1.59	0.306
4	2.25	1.85–2.72	<0.001	1.49	1.09–2.03	0.012
IPTW hazard model Treatment
Primary surgery	1.00
Primary CRT	1.22	1.10–1.35	<0.001