Table 3.

Association between epigenetic age acceleration and overall survival as well as progression-free survival cross-sectionally at different time points

Overall survival model	Main model				Sensitivity Analysis*
	N; events	Adjusted hazard ratio	p	95% confidence interval	N; events	Adjusted hazard ratio	p	95% confidence interval
Baseline	132; 21	1.06	0.23	[0.96, 1.17]	128; 21	1.02	0.78	[0.90, 1.14]
End of IMRT	117; 17	1.09	0.06	[1.00, 1.20]	108; 17	1.33	<0.001	[1.15, 1.62]
6-month post-IMRT	117; 20	1.11	0.004	[1.03, 1.18]	112; 20	1.07	0.13	[0.98, 1.17]
12-month post-IMRT	105; 16	1.10	0.02	[1.01, 1.19]	100; 16	1.15	0.04	[1.01, 1.33]
Progression free survival model
Baseline	132; 30	1.10	0.02	[1.02, 1.19]	128; 30	1.13	0.008	[1.03, 1.24]
End of IMRT	117; 26	1.14	<0.001	[1.06, 1.23]	108; 26	1.32	<0.001	[1.16, 1.54]
6-month post-IMRT	117; 27	1.08	0.01	[1.02, 1.14]	112; 27	1.08	0.03	[1.01, 1.17]
12-month post-IMRT	105; 22	1.07	0.05	[1.00, 1.15]	100; 22	1.04	0.46	[0.95, 1.14]

Note. All main models were adjusted for HPV status, feeding tubes, and treatment (radiation ± surgery vs. chemoradiation vs. chemoradiation + surgery). Sensitivity analysis further adjusted for age, race (white vs. non-white), history of tobacco use (yes vs. no), stage (IV vs. ≤III), functional status (ECOG=0 vs. ≥1), comorbidity (CCI =0 vs. ≥1), BMI×BMI (quadratic association), HNC cluster, and surgery (no vs. yes). HNC = head and neck symptom cluster, HPV = Human papillomavirus, IMRT = Intensity-Modulated Radiation Therapy. Bold text indicates a statistically significant association with a p-value less than 0.05.

^*The number of patients included in the sensitivity analysis was less than the main model due to a few missing from the added covariates.