Leaving colorectal polyps in situ with endocytoscopy assisted by computer-aided diagnosis: a cost-effectiveness study.

 Computer-aided diagnosis (CADx) enables the distinction between neoplastic and non-neoplastic polyps during colonoscopy. We aimed to estimate the patient-level benefit and harm of CADx.  We conducted a comparative analysis on data from the EndoBRAIN international clinical trial, evaluating the effect of optical diagnosis during colonoscopy with and without CADx. Three hypothetical scenarios were compared: "endoscopist-alone" and "CADx-assisted" leave-in-situ strategies (leaving non-neoplastic rectosigmoid polyps ≤ 5 mm), and "total removal" (removing all detected polyps). Primary outcomes included patient-level colonoscopy-related cost and surveillance interval agreement (colorectal cancer risk category). Estimates were calculated based on national reimbursement rates and guidelines in four countries.  We analyzed 1134 patients (59 % men, median age 67 years) with 1716 polyps. Compared with total removal, the endoscopist-alone and CADx-assisted leave-in-situ strategies reduced the removed polyps per patient from 1.51 (95 %CI 1.48-1.54) to 1.18 (95 %CI 1.16-1.20) and 1.12 (95 %CI 1.00-1.14), respectively; however, 0.023 (95 %CI 0.015-0.033) and 0.021 (95 %CI 0.014-0.031) neoplasms per patient were left in situ, respectively. The mean colonoscopy cost decreased by $44 (endoscopist alone) and $46 (CADx assistance) in the USA, $22 and $19 in the UK, $21 and $19 in Japan, and $32 and $30 in Norway, respectively. Surveillance interval agreement decreased to 99.2 % (endoscopist alone) and 99.0 % (CADx assistance) in the USA, 99.8 % and 99.8 % in the UK, 97.9 % and 97.1 % in Japan, and 99.9 % and 99.9 % in Norway, respectively.  Both endoscopist-alone and CADx-assisted optical diagnosis reduce colonoscopy costs. The risk of missed adenomas and surveillance interval deviations appear marginal.