Table 2. Stratification analysis for associations between ERCC2 SNPs and ESCC risk.

	rs238406				rs13181				Combined effect of risk genotypes
	(cases/controls)				(cases/controls)				(cases/controls)
Variables	GG	TG/TT	Adjusted OR (95% CI) a	P b	TT	TG/GG	Adjusted OR (95% CI) a	P b	0	≥1	Adjusted OR (95% CI) a	P b
Age, yr (median)
≤60	158/178	402/380	1.27 (0.97–1.66)	0.573	477/476	83/82	0.89 (0.63–1.26)	0.158	128/141	432/417	1.17 (0.87–1.56)	0.218
>60	167/196	395/357	1.26 (0.97–1.63)		460/478	102/75	1.44 (1.03–2.01)		120/156	442/397	1.39 (1.05–1.85)
Sex
Males	259/290	646/571	1.26 (1.02–1.55)	0.708	757/740	148/121	1.16 (0.88–1.52)	0.943	199/231	706/630	1.26 (1.01–1.58)	0.820
Females	66/84	151/166	1.24 (0.81–1.89)		180/214	37/36	1.18 (0.69–2.02)		49/66	168/184	1.31 (0.83–2.08)
Pack-years
0	133/155	295/356	0.94 (0.70–1.25)	0.036	363/444	65/67	1.20 (0.82–1.76)	0.717	107/126	321/385	0.97 (0.71–1.31)	0.050
≤16 (mean)	37/85	115/156	1.53 (0.95–2.47)		126/210	26/31	1.38 (0.77–2.50)		27/69	125/172	1.60 (0.95–2.70)
>16 (mean)	155/134	387/225	1.58 (1.17–2.13)		448/300	94/59	1.06 (0.73–1.55)		114/102	428/257	1.58 (1.14–2.20)
Drinking status
Never	173/245	451/504	1.26 (0.99–1.60)	0.935	525/648	99/101	1.21 (0.89–1.65)	0.797	131/197	493/552	1.33 (1.02–1.72)	0.782
Ever	152/129	346/233	1.25 (0.92–1.69)		412/306	86/56	1.03 (0.70–1.52)		117/100	381/262	1.20 (0.87–1.66)
BMI
<25.0	209/155	505/335	1.14 (0.89–1.47)	0.253	591/427	123/63	1.38 (0.99–1.93)	0.165	154/124	560/366	1.25 (0.95–1.64)	0.748
≥25.0	116/219	292/402	1.40 (1.06–1.84)		346/527	62/94	1.01 (0.71–1.43)		94/173	314/448	1.31 (0.98–1.75)

^aObtained in logistic regression models with adjustment for age, sex, BMI, smoking status and drinking status.

^bP for heterogeneity test using the Chi-square-based Q test.