The association of colonoscopy quality indicators with the detection of screen-relevant lesions, adverse events, and postcolonoscopy cancers in an asymptomatic Canadian colorectal cancer screening population

Background: Although several quality indicators of colonoscopy have been defined, quality assurance activities should be directed at the measurement of quality indicators that are predictive of key screening colonoscopy outcomes.

Objective: The goal of this study was to examine the association among established quality indicators and the detection of screen-relevant lesions (SRLs), adverse events, and postcolonoscopy cancers.

Design: Historical cohort study.

Setting: Canadian colorectal cancer screening center.

Patients: A total of 18,456 asymptomatic men and women ages 40 to 74, at either average risk or increased risk for colorectal cancer because of a family history, who underwent a screening colonoscopy from 2008 to 2010.

Main outcome measurements: Using univariate and multivariate analyses, we explored the association among procedural quality indicators and 3 colonoscopy outcomes: detection of SRLs, adverse events, and postcolonoscopy cancers.

Results: The crude rates of SRLs, adverse events, and postcolonoscopy cancers were 240, 6.44, and .54 per 1000 colonoscopies, respectively. Several indicators, including endoscopist withdrawal time (OR, 1.3; 95% CI, 1.2-1.4) and cecal intubation rate (OR, 13.9; 95% CI, 1.9-96.9), were associated with the detection of SRLs. No quality indicator was associated with the risk of adverse events. Endoscopist average withdrawal time over 6 minutes (OR, .12; 95% CI, .002-.85) and SRL detection rate over 20% (OR, .17; 95% CI, .03-.74) were associated with a reduced risk of postcolonoscopy cancers.

Limitations: Single-center study.

Conclusion: Quality assurance programs should prioritize the measurement of endoscopist average withdrawal time and adenoma (SRL) detection rate.