TABLE 3.

Odds ratios (95% CIs) for the association between low‐dose aspirin use and the risk of gastric cancer

	Cases (n = 727)		Controls (n = 5000)
Low‐dose aspirin	%	%	n	%	OR (95% CI) a	OR (95% CI) b
Recency of use
Nonuse	442	60.8	2404	48.1	1.0 (reference)	1.0 (reference)
Current use	146	20.1	1407	28.1	0.56 (0.46‐0.68)	0.46 (0.38‐0.57)
Primary CVD prevention	91	12.5	830	16.6	0.59 (0.46‐0.75)	0.51 (0.40‐0.65)
Secondary CVD prevention	55	7.6	577	11.5	0.52 (0.38‐0.69)	0.41 (0.30‐0.55)
Remaining current users c	66	9.1	730	14.6	0.46 (0.35‐0.61)	0.31 (0.23‐0.42)
Recent use	26	3.6	146	2.9	0.93 (0.60‐1.43)	0.66 (0.42‐1.02)
Past use	47	6.5	313	6.3	0.80 (0.58‐1.10)	0.57 (0.41‐0.79)
Dose d
75 mg	143	19.7	1377	27.5	0.56 (0.46‐0.69)	0.46 (0.38‐0.57)
150 mg	2	0.3	14	0.3	0.77 (0.17‐3.39)	0.78 (0.17‐3.62)
300 mg	1	0.1	16	0.3	0.34 (0.04‐2.55)	0.28 (0.04‐2.15)
Duration of low‐dose aspirin use d
>1 to <3 years	56	7.7	693	13.9	0.42 (0.31‐0.56)	0.34 (0.25‐0.46)
>3 to <5 years	63	8.7	508	10.2	0.68 (0.51‐0.90)	0.57 (0.43‐0.77)
≥5 years	27	3.7	206	4.1	0.76 (0.50‐1.16)	0.66 (0.43‐1.01)
Concomitant use of low‐dose aspirin and another medication d , e
Low‐dose aspirin plus clopidogrel	7	1.0	43	0.9	0.90 (0.40‐2.02)	0.62 (0.27‐1.42)
Low‐dose aspirin plus NSAID	7	1.0	95	1.9	0.39 (0.18‐0.85)	0.27 (0.12‐0.58)
Low‐dose aspirin plus PPI	97	13.3	454	9.0	2.77 (2.09‐3.67)	1.94 (1.45‐2.60)

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.