Table 4:

Cox proportional hazards analyses and model validation

	HR	95%CI/C-Index	P Value
Clinical variable (95% CI)
HPV status, positive	0.26	(0.09–0.7)	.008^{^a}
Smoking history, smoker	1.9	(0.66–5.44)	.23
Age, older than 65 years	0.97	(0.34–2.78)	.96
Sex, female	0.51	(0.07–3.83)	.51
T-stage, ≥III	3.66	(1.34–9.99)	.01^{^a}
N-stage, ≥II	1.62	(0.62–4.19)	.32
Overall stage, >IV	2.7	(0.95–7.68)	.06
Rad-score, high-risk	3.72	(1.21–11.46)	.02^{^a}
Multivariate model (C-index)
Cancer stage (model 1)		0.621	.03
Cancer stage + HPV status (model 2)		0.702	.01
Cancer stage + HPV status + rad-score (model 3)		0.733	.01
Validation (C-index)
Internal validation on test set		0.866	.01
External validation on TCIA set		0.72	<.001