Table 6.

Summary of epidemiologic studies of smoking and adenomas, serrated polyps, and both types

References	Population, location	Study design	Adenomas only Category Category n OR/RR (95 % CI) current versus never smokers	Serrated polyps only Category Category n OR/RR (95 % CI) current versus never smokers	Adenomas and serrated polyps Category n OR/RR (95 % CI) current versus never smokers
Figueiredo 2014 [current study]	Multicenter, PPSG	RCT/cohort, colonoscopy-based	n = 661 RR = 1.31 (1.08, 1.58)	n = 295 RR = 2.33 (1.76, 3.07)	n = 299 RR = 2.27 (1.68, 3.06)
Burnett-Hartman [20]	Group Health Cooperative, Washington State	Case–control, colonoscopy-based	n = 628 OR = 1.56 (0.99, 2.44)	n = 594 OR = 3.00 (1.93, 4.66)	n = 247 OR = 2.82 (1.65, 4.81)
Fu [19]	Vanderbilt Medical Center and Tennessee Valley VA, Nashville, TN	Case–control, colonoscopy-based	n = 1,444 OR = 1.96 (1.61, 2.38)	n = 662 OR = 4.44 (3.47, 5.67)	n = 437 OR = 6.10 (4.51, 8.25)
Ji [6]	Multicenter, PLCO	Case–control, sigmoidoscopy-based	n = 2,500 OR = 1.8 (1.5, 2.1)	n = 1,762 OR = 4.4 (3.7, 5.2)	n = 582 OR = 6.2 (4.7, 8.3)
Morimoto [10]	Multiclinic private gastroenterology practice, Minneapolis, MN	Case–control, colonoscopy-based	n = 437 OR = 1.3 (0.8, 2.3)	n = 219 OR = 4.1 (2.2, 7.6)	n = 138 OR = 6.1 (2.8, 13.5)

RR risk ratio; OR odds ratio; CI confidence interval; RCT randomized controlled trial; PPSG Polyp Prevention Study Group; PLCO prostate, lung, colorectal, and ovarian cancer screening trial