Table 2. Adjusted HRa with 95% CI of squamous oral–oesophageal cancer by daily coffee consumption.

	0, <1 cup	1–4 cups	5–8 cups	9+ cups	HR per 1 unit	P-trend
All
Cases	35	139	207	69
Pyrs	580 385	2 213 629	2 184 454	619 489
HR	1.01	Ref	1.16	0.96	1.02	0.79
95% CI	(0.70, 1.47)		(0.93, 1.45)	(0.71, 1.31)	(0.90, 1.14)
Men
Cases	30	87	148	60
Pyrs	271 137	975 204	1 089 176	379 842
HR	1.33	Ref	1.24	1.11	1.01	0.88
95% CI	(0.88, 2.02)		(0.95, 1.63)	(0.78, 1.58)	(0.88, 1.16)
Women
Cases	5	52	59	9
Pyrs	309 248	1 238 424	1 095 277	239 647
HR	0.42	Ref	1.04	0.57	1.03	0.78
95% CI	(0.17, 1.05)		(0.71, 1.53)	(0.27, 1.20)	(0.82, 1.30)
Non-smokers
Cases	18	77	66	15
Pyrs	466 172	1 586 749	1 091 824	172 339
HR	0.78	Ref	1.14	1.51	1.22	0.043
95% CI	(0.47, 1.30)		(0.82, 1.59)	(0.87, 2.64)	(1.01, 1.47)
Smokers
Cases	17	62	141	54
Pyrs	114 212	626 880	1 092 630	447 150
HR	1.43	Ref	1.19	0.87	0.91	0.24
95% CI	(0.84, 2.45)		(0.88, 1.61)	(0.60, 1.27)	(0.79, 1.06)
Boiled coffee
Cases	2	39	74	32
Pyrs	30 669	611 247	703 807	231 139
HR	0.88	Ref	1.26	1.17	1.10	0.40
95% CI	(0.21, 3.64)		(0.85, 1.87)	(0.71, 1.92)	(0.88, 1.39)
Other coffee
Cases	33	100	133	37
Pyrs	549 715	1 602 381	1 480 646	388 350
HR	1.01	Ref	1.11	0.83	0.98	0.73
95% CI	(0.68, 1.51)		(0.85, 1.54)	(0.56, 1.24)	(0.85, 1.12)

Abbreviations: CI=confidence interval; HR=hazard ratios; Pyrs=person years.

^aAdjusted for sex (except when stratified by sex), daily smoking (except in non-smokers), body mass index and education.