BACKGROUND & AIMS:We performed a systematic review and meta-analysis to comprehensively estimate adenoma miss rate (AMR) and advanced AMR (AAMR) and explore associated factors. METHODS: We searched the PubMed, Web of Science, and Ovid EMBASE databases for studies published through April 2018 on tandem colonoscopies, with AMR and AAMR as the primary outcomes. We performed meta-regression analyses to identify risk factors and factors associated with outcome. Primary outcomes were AMR and AAMR and secondary outcomes were AMR and AAMR for different locations, sizes, pathologies, morphologies, and populations. RESULTS: In a meta-analysis of 43 publications and more than 15,000 tandem colonoscopies, we calculated miss rates of 26% for adenomas (95% confidence interval [CI] 23%-30%), 9% for advanced adenomas (95% CI 4%-16%), and 27% for serrated polyps (95% CI 16%-40%). Miss rates were high for proximal advanced adenomas (14%; 95% CI 5%-26%), serrated polyps (27%; 95% CI 16%-40%), flat adenomas (34%; 95% CI 24%-45%), and in patients at high risk for colorectal cancer (33%; 95% CI 26%-41%). Miss rates could be decreased by adequate bowel preparation and auxiliary techniques (P ¼ .06; P ¼ .04, and P ¼ .01, respectively). The adenoma detection rate (ADR), adenomas per index colonoscopy, and adenomas per positive index colonoscopy (APPC) were independently associated with AMR (P ¼ .02, P ¼ .01, and P ¼ .008, respectively), whereas APPC was the only factor independently associated with AAMR (P ¼ .006). An APPC value greater than 1.8 was more effective in monitoring AMR (31% vs 15% for AMR P < .0001) than an ADR value of at least 34% (27% vs 17% for AMR; P ¼ .008). The AAMR of colonoscopies with an APPC value below 1.7 was 35%, vs 2% for colonoscopies with an APPC value of at least 1.7 (P ¼ .0005). CONCLUSIONS: In a systematic review and meta-analysis, we found that adenomas and advanced adenomas are missed (based on AMR and AAMR) more frequently than previously believed. In addition to ADR,

Objective Adequate bowel preparation is essential for a successful colonoscopy; clinical studies suggest reinforced education can improve the preparation process. However, there have been no trials to compare WeChat directions (the most widely used social media app in China) with those of the short message service (SMS). This study was aimed to assess the effect of WeChat and SMS on the bowel preparation quality. Participants and methods This was a single-center, prospective, endoscopically blinded, randomized, controlled study. Patients in reinforced education groups received additional reminder messages by WeChat and SMS 2 days before colonoscopy. The primary outcome was bowel preparation quality evaluated by the Boston bowel preparation scale (BBPS) score and the rate of adequacy (BBPS score ≥6). Secondary outcomes included polyp detection rate, adenoma detection rate, and mean total adenomas detected. Patient tolerance level and subjective feelings were also evaluated. Results The total BBPS score and the percentage of adequacy were significantly higher in the reinforced education groups compared with the control (WeChat vs. control, P<0.001; SMS vs. control, P<0.001). Moreover, statistically significant differences between the two interventions were found in the total BBPS score but not in the rate of adequacy (P=0.007 and 0.561, respectively). The detection of adenomas, using multiplicity detection rate, advanced adenoma detection rate, and mean total adenomas detected, was much higher in the intervention groups (P=0.039, 0.037, and 0.019, respectively). Conclusion WeChat was superior to SMS for bowel preparation, although both of them may help improving the detection of adenomas.

Combined use of PEG and simethicone is associated with a significantly increased ADR in a Chinese population.