Impact of withdrawal time on the adenoma detection rate in elderly patients during unsedated colonoscopy: a retrospective multicenter study.

Background: Colonoscopy withdrawal time is recognized as a key factor influencing the adenoma detection rate (ADR). Current clinical guidelines recommend a minimum colonoscopy withdrawal time of 6 min. However, the optimal withdrawal time for unsedated colonoscopy in elderly patients and its impact on ADR remain uncertain.

Methods: In this retrospective multicenter study, we collected the withdrawal time (excluding bowel cleansing and polyp resection time) of unsedated colonoscopy in elderly patients, to analyze the relationship between withdrawal time in 1-minute increments and ADR, and the effect of withdrawal time > 8 min compared with withdrawal time ≤ 8 min on ADR. Multivariate linear regression analysis was employed to assess the optimal withdrawal time influencing ADR.

Results: A total of 1119 samples (mean age, 70.32 ± 7.17 years; 57.28% male) were included in the analysis, with a median withdrawal time of 9 min (interquartile range [IQR], 7-13). The ADR was highest at a withdrawal time of 8 min (67.02%), while the adenocarcinoma detection rate (ACDR) peaked at a withdrawal time of 8 min (17.02%). In addition, patients with withdrawal time > 8 min exhibited a higher ADR than those with ≤ 8 min (odds ratio (OR), 1.63; 95% confidence interval (CI), 1.28-2.06; P < 0.001).

Conclusions: This retrospective multicenter study demonstrates that in elderly patients with contraindications to sedation, achieving a minimum withdrawal time of 8 min during unsedated colonoscopy is critical for optimizing ADR.