Table 3. Cox regression analysis for the risk of death among recurrent HNSCC patients.

	Univariate Analysis			Multivariate Analysis*
Variable	HR	(95% CI)	p value	HR	(95% CI)	p value
Treatment group (Reference group: CT alone)
Re-RT alone (2)	1.02	(0.86–1.22)	0.817	1.00	(0.83–1.20)	0.992
CCRT (3)	0.72	(0.64–0.81)	<0.001	0.70	(0.62–0.79)	<0.001
Surgery ± RT/CT (4)	0.37	(0.33–0.41)	<0.001	0.37	(0.34–0.42)	<.0001
Age ≥ 65 years	1.11	(1.00–1.24)	0.058	1.13	(1.01–1.26)	0.040
Men	1.09	(0.93–1.28)	0.299	1.10	(0.93–1.29)	0.263
CCI score > 6	1.08	(1.07–1.10)	<0.001	1.09	(1.07–1.10)	<.0001
Clinical stage at first diagnosis	1.31	(1.27–1.36)	<0.001	1.24	(1.20–1.29)	<.0001
Recurrence-free interval > 1 year	0.65	(0.59–0.71)	<0.001	0.69	(0.63–0.76)	<.0001

*All above variables were used in multivariate analysis.

Abbreviations: RT, radiotherapy; CT, chemotherapy; CCRT, concurrent chemoradiotherapy; CCI, Charlson comorbidity index; CI, confidence interval; HR, hazard ratio.