Colonoscopy withdrawal times and adenoma detection rates in a large, multi-site colorectal surgery practice.

Abstract

433 Background: Colonoscopy withdrawal times (CWT) and adenoma detection rates (ADR) have been extensively correlated in medical literature. The American College of Gastroenterology (ACG) 2021 guidelines recommend measuring quality indicators for screening colonoscopy that achieve minimum benchmarks for ADR (>=25%) and CWT (>=6 minutes). In October 2022, M Desai et al reported in a sample of 1142 patients (46% screening and 54% surveillance), ADR increased as withdrawal time increased from 6 to 13 minutes. Results demonstrated a 6% increase per minute in the likelihood of detecting an additional patient with at least 1 adenoma. Texas Colon and Rectal Specialists routinely reviews ADR’s and CWT’s. This retrospective descriptive study presents a concise review of the correlation between CWT’s and ADR’s in a homogenous set of screening and surveillance patients. Methods: We examined 7164 abstracted colonoscopy records from 31 colorectal surgeons. Diagnostic colonoscopies were excluded. We studied patients between 45 and 84 years of age at the time of the colonoscopy. Each patient was noted for the colonoscopy CWT as well as whether at least one adenomatous polyp was detected. These data were reported in a scatter plot of ADR over CWT as well as a bubble chart of ADR over CWT by each surgeon. A two-sample t-test confirmed a statistical difference between the mean CWT of the adenoma-positive patients and those that were not positive. Results: Consistent with the literature, ADR increased with CWT. The mean CWT was 14.2 minutes in the group where an adenoma was detected (n=3289) and 10.6 minutes in the group where an adenoma was not detected (n=3875), (p<0.05 and CI of 95%). Mean CWT was 12.3 minutes, mode was 7 minutes, median was 10.25 minutes, and the mean ADR was 45.9%. The best ADR performance was 62.5% at a mean of 26.8 minutes CWT and the worst performance was 27.7% at 10 minutes CWT. A bubble chart demonstrates the relationship between CWT and ADR by surgeon with the bubbles representing individual colonoscopy volumes. Consistent with the literature, ADR increased with CWT. The mean CWT was 14.2 minutes in the group where an adenoma was detected (n=3289) and 10.6 minutes in the group where an adenoma was not detected (n=3875), (p<0.05 and CI of 95%). Mean CWT was 12.3 minutes, mode was 7 minutes, median was 10.25 minutes, and the mean ADR was 45.9%. The best ADR performance was 62.5% at a mean of 26.8 minutes CWT and the worst performance was 27.7% at 10 minutes CWT. Conclusions: Our data indicate a significant relationship between CWT and ADR, and may suggest that CWT well beyond six minutes may yield better ADR’s. Furthermore, scope volume appears to play a role in the achievement of higher ADR’s, though this would require further investigation for optimal CWT, minimum expected ADR, optimal techniques and bowel prep, and emerging assistive technology.