9-Minute Withdrawal Time Cuts Adenoma Miss Rate in Colonoscopy

TUESDAY, May 23, 2023 (HealthDay News) -- A 9-minute mean withdrawal time (m-WT) for screening colonoscopy significantly reduces the adenoma miss rate (AMR) and advanced adenoma miss rate (AAMR), in addition to increasing adenoma detection rate (ADR), according to a study published in the May issue of the American Journal of Gastroenterology.

Shengbing Zhao, M.D., from the National Quality Control Center of Digestive Endoscopy in Shanghai, and colleagues conducted a multicenter trial in 11 centers involving 733 asymptomatic participants who were randomly assigned to receive segmental tandem screening colonoscopy with a 9-minute withdrawal followed by a 6-minute withdrawal or vice versa (9-minute-first group [9MF], 366 participants; 6-minute-first group [6MF], 367 participants). Lesion-level AMR was the primary outcome.

The researchers found that the 9MF significantly reduced the lesion-level and participant-level AMR (14.5 versus 36.6 percent and 10.9 versus 25.9 percent, respectively), AAMR (5.3 versus 46.9 percent), multiple adenoma miss rate (20.7 versus 56.5 percent), and high-risk adenoma miss rate (14.6 versus 39.5 percent) of 6MF in the intention-to-treat analysis, without reducing the efficiency of detection. A lower false-negative rate was seen for adenomas and high-risk adenomas as well as a lower rate of shortening surveillance schedule in 9MF, accompanied by improved ADR in the 9- versus 6-minute m-WT (42.3 versus 33.5 percent). Even after adjusting for ADR, the independent inverse association between m-WT and AMR remained significant; 9-minute m-WT was an independent predictor for AMR and AAMR.

"Along with the evidence from current trial and previous findings, we suggest that in addition to ADR, the 9-minute WT deserves to be considered as a potential quality indicator to further optimize colonoscopy quality," the authors write.

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