Table 3.

The risk of gastrointestinal cancer among aspirin and non-aspirin non-steroidal anti-inflammatory drug (NSAID) users, by estimated duration of use, expressed as standardised incidence ratios (SIRs) and 95% CIs.

	Aspirin only (n=783 870)			Non-selective non-aspirin NSAIDs (n=566 209)
	Categories (quartiles)	Number of cases	SIRs (95% CI)	Categories (quartiles)	Number of cases	SIRs (95% CI)
Gastrointestinal cancer
	0.5–2.5 years	4158	2.77 (2.69 to 2.85)	0.5–0.7 years	865	1.00 (0.93 to 1.06)
	2.5–5.5 years	4532	1.83 (1.77 to 1.88)	0.7–1.1 years	832	0.92 (0.86 to 0.98)
	5.5–7.7 years	1310	0.31 (0.30 to 0.33)	1.1–2.1 years	977	0.86 (0.80 to 0.91)
	>7.7 years	969	0.37 (0.35 to 0.40)	>2.1 years	754	0.54 (0.50 to 0.58)
Oesophageal cancer
	0.5–2.5 years	204	2.91 (2.52 to 3.33)	0.5–0.7 years	35	0.93 (0.65 to 1.29)
	2.5–5.5 years	216	1.83 (1.60 to 2.09)	0.7–1.1 years	32	0.84 (0.57 to 1.18)
	5.5–7.7 years	61	0.31 (0.24 to 0.40)	1.1–2.1 years	43	0.91 (0.66 to 1.23)
	>7.7 years	58	0.56 (0.42 to 0.72)	>2.1 years	23	0.41 (0.26 to 0.61)
Gastric cancer
	0.5–2.5 years	61	2.89 (2.62 to 3.19)	0.5–0.7 years	55	0.73 (0.55 to 0.95)
	2.5–5.5 years	466	2.00 (1.82 to 2.19)	0.7–1.1 years	61	0.78 (0.60 to 1.01)
	5.5–7.7 years	99	0.26 (0.21 to 0.31)	1.1–2.1 years	80	0.82 (0.65 to 1.02)
	>7.7 years	110	0.45 (0.37 to 0.55)	>2.1 years	64	0.54 (0.42 to 0.69)
Small bowel cancer
	0.5–2.5 years	96	2.78 (2.25 to 3.39)	0.5–0.7 years	22	0.94 (0.59 to 1.43)
	2.5–5.5 years	109	1.94 (1.59 to 2.33)	0.7–1.1 years	20	0.83 (0.51 to 1.29)
	5.5–7.7 years	26	0.28 (0.18 to 0.41)	1.1–2.1 years	25	0.85 (0.55 to 1.25)
	>7.7 years	22	0.39 (0.25 to 0.60)	>2.1 years	27	0.76 (0.50 to 1.11)
Colorectal cancer
	0.5–2.5 years	2658	2.78 (2.67 to 2.88)	0.5–0.7 years	540	0.99 (0.91 to 1.08)
	2.5–5.5 years	2844	1.79 (1.73 to 1.86)	0.7–1.1 years	489	0.86 (0.78 to 0.94)
	5.5–7.7 years	813	0.31 (0.29 to 0.33)	1.1–2.1 years	565	0.78 (0.72 to 0.85)
	>7.7 years	604	0.36 (0.33 to 0.39)	>2.1 years	423	0.47 (0.43 to 0.52)
Liver cancer
	0.5–2.5 years	222	2.63 (2.30 to 3.00)	0.5–0.7 years	63	1.23 (0.95 to 1.57)
	2.5–5.5 years	272	1.96 (1.74 to 2.21)	0.7–1.1 years	53	1.02 (0.76 to 1.33)
	5.5–7.7 years	100	0.44 (0.35 to 0.53)	1.1–2.1 years	70	1.10 (0.86 to 1.39)
	>7.7 years	51	0.40 (0.30 to 0.53)	>2.1 years	46	0.61 (0.45 to 0.81)
Gallbladder and biliary tract cancer
	0.5–2.5 years	137	2.36 (1.98 to 2.79)	0.5–0.7 years	42	1.17 (0.85 to 1.58)
	2.5–5.5 years	143	1.52 (1.28 to 1.79)	0.7–1.1 years	51	1.34 (1.00 to 1.76)
	5.5–7.7 years	61	0.39 (0.30-.50)	1.1–2.1 years	52	1.06 (0.79 to 1.39)
	>7.7 years	44	0.40 (0.29 to 0.53)	>2.1 years	45	0.73 (0.53 to 0.98)
Pancreatic cancer
	0.5–2.5 years	424	2.79 (2.53 to 3.06)	0.5–0.7 years	107	1.09 (0.90 to 1.32)
	2.5–5.5 years	467	1.87 (1.71 to 2.06)	0.7–1.1 years	123	1.20 (1.00 to 1.43)
	5.5–7.7 years	149	0.36 (0.30 to 0.42)	1.1–2.1 years	136	1.05 (0.88 to 1.25)
	>7.7 years	74	0.28 (0.23 to 0.37)	>2.1 years	124	0.78 (0.65 to 0.93)