Table 1. Distribution of selected demographic variables and risk factors in ESCC cases and controls.

Variable	Cases (n=629)		Controls (n=686)		p a
	n	%	n	%
Age (years) mean ± SD	62.85 (±8.13)		62.58 (±7.89)		0.541
Age (years)					0.155
< 63	310	49.28	365	53.21
≥ 63	319	50.72	321	46.79
Sex					0.185
Male	444	70.59	461	67.20
Female	185	29.41	225	32.80
Tobacco use					<0.001
Never	355	56.44	499	72.74
Ever	274	43.56	187	27.26
Alcohol use					<0.001
Never	428	68.04	526	76.68
Ever	201	31.96	160	23.32

^a Two-sided χ² test and student t test; Bold values are statistically significant (p <0.05).