Table 4.

Univariate Cox Models for Patient and Treatment Characteristics^a Related to Overall Survival

Risk Factor	No.	Coefficient (SE)	Wald χ2	Risk Ratio	95% CI for Risk Ratio	P Value
Academic hospital	352	−0.60 (0.16)	14.40	0.55	0.40–0.75	<.001
Female sex	385	0.21 (0.16)	1.66	1.23	0.90–1.69	.197
Age at diagnosis, per year	384	0.02 (0.01)	10.39	1.02	1.01–1.03	.001
Income, per $10,000	384	−0.10 (0.05)	4.17	0.91	0.82–1.00	.041
Married	375	−0.55 (0.16)	12.14	0.58	0.43–0.79	.001
Distance from home, per 100 miles	385	0.03 (0.05)	0.423	1.03	0.94–1.13	.516
Private insurance	340	−0.36 (0.16)	4.99	0.70	0.51–0.96	.026
Metro zip code	385	−0.19 (0.17)	1.28	0.83	0.60–1.15	.259
Drink alcohol	362
Never [reference]				1.00
Former		0.15 (0.23)	0.46	1.17	0.75–1.82	.499
Current		0.13 (0.20)	0.39	1.13	0.77–1.68	.533
Current smoker	365	0.62 (0.16)	15.11	1.85	1.36–2.53	<.001
Lung disease	369	0.96 (0.20)	24.20	2.62	1.78–3.84	<.001
Arthritis	369	0.51 (0.22)	5.45	1.66	1.09–2.54	.020
Diabetes	368	0.66 (0.25)	7.03	1.94	1.19–3.17	.008
Heart disease	369	0.49 (0.21)	5.53	1.63	1.09–2.45	.019
Depression/mental illness	367	0.45 (0.23)	3.81	1.57	1.00–2.46	.051
Tumor site	385
Oral cavity/oropharynx [reference]				1.00
Hypopharynx/larynx		0.40 (0.18)	4.98	1.49	1.05–2.11	.026
Sinus/nose		0.31 (0.23)	1.75	1.36	0.86–2.16	.186
Other		−0.10 (0.31)	0.10	0.91	0.50–1.66	.755
Stage TNM	301	0.04 (0.09)	0.25	1.05	0.88–1.24	.614
Adjuvant radiation	374	0.12 (0.16)	0.58	1.13	0.83–1.53	.445
Radiation with chemotherapy	374	0.15 (0.16)	0.83	1.16	0.84–1.59	.363

Abbreviations: CI, confidence interval; SE, standard error.

^aOther patient and treatment factors were excluded due to a very low prevalence rate, too many missing values, or colinearity with other covariates.