Colonoscopy Withdrawal Time and Adenoma Detection Rate: A Japanese Multicenter Analysis

AIM : Limited evidence exists on the relationship between colonoscopy withdrawal time and adenoma detection rate in Japan. We aimed to clarify the clinical impact of colonoscopy withdrawal time in a Japanese setting. MATERIALS AND METHODS : We recruited 6,919 consecutive patients from four Japanese endoscopic centers between April 2010 and April 2011. Colonoscopists were divided into the following groups based on the median withdrawal time of a negative colonoscopy: <6 min (group A), 6–9 min (group B), and ≥10 min (group C). We analyzed the relationship between these withdrawal time groups and adenoma detection rateusing multiple logistic regression analysis. RESULTS : The final analysis included 3,862 patients. Group A included 201 (3 colonoscopists), group B included 2,741 (13 colonoscopists), and group C included 920patients (9 colonoscopists). We found that adenoma detection rates tended to increase with longer median negative colonoscopy withdrawal times ( p <0.01). Compared with group A, the odds ratios in group B and group C were 1.98 (95% confidence interval [CI], 1.42–2.76) and 2.51 (95% CI, 1.68–3.75), respectively. CONCLUSIONS : A colonoscopy withdrawal time of over 6 min appears to be a quality indicator for colonoscopy even in a Japanese setting.