Table 4.

Odds Ratios for the Association Between Use of Nonsteroidal Antiinflammatory Drugs and Distal Large Bowel Cancer, by Tumor Location, North Carolina Colon Cancer Study II, 2001–2006

	Sigmoid Colon				Rectosigmoid Junction				Rectum
	Cases		Multivariable ORa	95% CI	Cases		Multivariable ORa	95% CI	Cases		Multivariable ORa	95% CI
	No.	%			No.	%			No.	%
Never use (referent)	97	20.7	1.00		47	28.0	1.00		104	27.2	1.00
Ever use	371	79.3	0.81	0.60, 1.09	121	72.0	0.50	0.33, 0.74	279	72.9	0.60	0.44, 0.81
Recent useb	338	72.2	0.79	0.58, 1.07	107	63.7	0.47	0.32, 0.71	242	63.2	0.55	0.41, 0.75
Average monthly use in the past 5 years, no. of times
<15	213	45.5	0.84	0.61, 1.15	76	45.2	0.55	0.36, 0.85	156	40.7	0.61	0.44, 0.85
≥15	158	33.8	0.78	0.56, 1.09	45	26.8	0.43	0.27, 0.69	123	32.1	0.58	0.41, 0.82
Regular usec of NSAIDs, by type
Over-the-counter aspirin	187	39.9	0.83	0.60, 1.16	44	26.2	0.39	0.24, 0.62	124	32.4	0.54	0.38, 0.75
Over-the-counter, nonaspirin NSAIDs	53	11.3	0.81	0.52, 1.26	17	10.1	0.45	0.24, 0.86	49	12.8	0.76	0.49, 1.17
Prescription nonselective NSAIDs	33	7.1	0.71	0.43, 1.18	19	11.3	0.86	0.46, 1.60	14	3.7	0.30	0.15, 0.57
Selective COX-2 inhibitors	42	9.0	0.53	0.33, 0.83	18	10.7	0.48	0.26, 0.89	27	7.1	0.34	0.20, 0.57

Abbreviations: CI, confidence interval; COX-2, cyclooxygenase 2; NSAIDs, nonsteroidal antiinflammatory drugs; OR, odds ratio.

^aAdjusted for age (continuous), sex, race (African-American or white), sampling probability, body mass index (weight (kg)/height (m)²; <25, 25–29.9, or ≥30) 1 year prior, ever use of calcium supplements in the past 5 years, physical activity 1 year prior (<1,882, 1,882–2,077, or ≥2,078 metabolic equivalent-minutes/day), total energy intake (<1,711, 1,711–2,413, or ≥2,414 kcal/day), and dietary fat intake (<64, 64–97, or ≥98 g/day).

^bContinuing use in the year before diagnosis/interview.

^cAmong ever users, use at least 3 times per week for 3 months or more.