808 Double-Blind, Randomized, Placebo-Controlled, Multicenter Trial of Mesalamine for the Prevention of Recurrence of Diverticulitis

Abstract

of 0), low (score of 1-3), intermediate (score of 4-6), and high (score of 6-12) risk groups, with respective risks of AN of 1.9% (95% CI, 0.63-4.43%), 4.7%, 9.9% and 25% (trend test, P,0.0001). Very-low and low-risk groups had 1 and 4 CRCs, respectively, all of which were distal. Based on finding a distal sentinel polyp, sigmoidoscopy to the descending colon for subjects in the two lowest risk groups (N=1591; 53% of the sample) would have detected 64 (94%) of 68 ANs. Among 1475 subjects in the validation set (mean age of 57.2± 7.0 years, 52% women), the prevalence of AN was 8.4%; a FHx of CRC was present in 9.2%. Risk of AN in the very low risk group was 1.65% (CI, 0.20-5.84%) and was 3.3%, 10.9%, and 22% in the low-risk, intermediate-risk, and high-risk groups, respectively (P,0.0001). In the two lowest risk subgroups (N=786; 54% of the sample), there were no CRCs, and sigmoidoscopy would have detected 21 (87.5%) of 24 ANs. Conclusion: This new risk index effectively stratifies the risk for AN among asymptomatic adults, identifying low-risk subgroups that may be screened effectively with methods other than colonoscopy. If validated in other settings, use of this index in clinical practice may increase the uptake and efficiency of CRC screening in the U.S.