TABLE 4.

Odds ratio (95% CIs) for the association between low‐dose aspirin and the risk of oesophageal cancer

	Cases (n = 1394)		Controls (n = 5000)
Low‐dose aspirin	n	%	n	%	OR (95% CI) a	OR (95% CI) b
Recency of use
Nonuse	829	59.5	2555	51.1	1.0 (reference)	1.0 (reference)
Current use	331	23.7	1397	27.9	0.73 (0.63‐0.84)	0.59 (0.51‐0.69)
Primary CVD prevention	180	12.9	821	16.4	0.67 (0.56‐0.80)	0.56 (0.46‐0.67)
Secondary CVD prevention	151	10.8	576	11.5	0.80 (0.66‐0.98)	0.64 (0.52‐0.78)
Remaining current users c	103	7.4	625	12.5	0.49 (0.39‐0.61)	0.33 (0.26‐0.42)
Recent use	63	4.5	133	2.7	1.43 (1.04‐1.95)	0.95 (0.69‐1.31)
Past use	68	4.9	290	5.8	0.71 (0.54‐0.94)	0.49 (0.37‐0.65)
Dose d
75 mg	303	21.7	1323	26.5	0.70 (0.60‐0.81)	0.57 (0.49‐0.67)
150 mg	3	0.2	14	0.3	0.65 (0.19‐2.26)	0.58 (0.16‐2.09)
300 mg	8	0.6	16	0.3	1.52 (0.65‐3.56)	1.02 (0.42‐2.44)
Duration of low‐dose aspirin use d
>1 to <3 years	145	10.4	680	13.6	0.64 (0.52‐0.78)	0.51 (0.41‐0.62)
>3 to <5 years	95	6.8	372	7.4	0.79 (0.62‐1.00)	0.64 (0.55‐0.92)
≥5 years	91	6.5	345	6.9	0.83 (0.65‐1.07)	0.71 (0.55‐0.92)
Concomitant use of low‐dose aspirin and another medication d , e
Low‐dose aspirin plus clopidogrel	6	0.4	54	1.1	0.34 (0.15‐0.80)	0.23 (0.10‐0.56)
Low‐dose aspirin plus NSAID	21	1.5	84	1.7	0.74 (0.45‐1.20)	0.58 (0.36‐0.96)
Low‐dose aspirin plus PPI	234	16.8	426	8.5	4.21 (3.41‐5.19)	3.18 (2.55‐3.95)

Abbreviations: CI, confidence interval; CVD, cardiovascular disease; GP, general practitioner; OR, odds ratio; PPI, proton pump inhibitor; NSAID, nonsteroidal anti‐inflammatory drug.

^aAdjusted by the matching factors: sex, age and calendar year.

^bAdjusted by the matching factors: sex, age, and calendar year, and by smoking and number of GP visits in the previous year.

^cCurrent users of low‐dose aspirin with less than 1 year duration of use.

^dAmong current users of low‐dose aspirin with ≥1 year duration of use.

^eCompared to no use of either drug in the year before the index date.