Abstract
Background and study aims Reliable adenoma detection requires "adequate" bowel preparation. The adenoma detection rate (ADR) was assessed in patients with high-quality (stool-free) cleansing versus adequate cleansing. Patients and methods This study was a post-hoc combined analysis of three randomized trials individually powered for cleansing quality assessment. Treatment-independent ADR was assessed versus colon cleansing quality by central readers using the Harefield Cleansing Scale (HCS) and the Boston Bowel Preparation Scale (BBPS). The number needed to treat (NNT) to find an additional patient with at least one adenoma was calculated for high-quality versus adequate-quality cleansing. Results A total of 1749 patients were included. ADR increased with high-quality versus adequate-quality cleansing: HCS grade A versus B, 39 % (94/242) versus 27 % (336/1229); NNT = 8.7; P < 0.001. ADR also increased with high-quality versus uniform adequate segmental cleansing scores: HCS grade A versus uniform segmental scores 2, 39 % (94/242) versus 26 % (97/379); NNT = 7.5; P < 0.001. ADR increased with top-quality versus adequate segmental cleansing scores: HCS uniform segmental scores 4 versus 2, 54 % (21/39) versus 26 % (97/379); NNT = 3.6; P < 0.001. ADR increased with BBPS 9 versus 6, 43 % (71/166) versus 26 % (247/950); NNT = 6.0; P < 0.001. Right colon ADR increased with top-quality versus adequate cleansing: HCS 4 versus 2, 20 % (25/122) versus 11 % (121/1117); NNT = 10.4; P < 0.001 and BBPS 3 versus 2, 15 % (42/284) versus 11 % (130/1192); NNT = 25.8; P = 0.033. Conclusions High-quality colon cleansing improves adenoma detection, and it should be a priority for bowel preparations for colonoscopy.