Table 1. Demographic characteristics of SCCOP patients by HPV16 status.

Variable	HPV16+ patients (N =439)		HPV16- patients (N =113)		P value*
	No.	%	No.	%
Age					0.856
≤54 years	225	51.2	59	52.2
>54 years	214	48.8	54	47.8
Sex					0.0012
Male	384	87.5	85	75.2
Female	55	12.5	28	24.8
Ethnicity					0.141
Non-Hispanic white	404	92.0	99	87.6
Others	35	8.0	14	12.4
Tobacco smoking					0.050
Ever	252	57.4	76	67.0
Never	187	42.6	37	33.0
Alcohol drinking					0.483
Ever	331	75.4	88	78.6
Never	108	24.6	25	21.4

*Two-sided χ² test.