Objectives: Adenoma detection rate (ADR) is the accepted rate marker in colonoscopy quality. Advanced adenomas detected at index colonoscopy, while less frequent than nonadvanced adenomas, carry greater risk for future advanced neoplasia during surveillance colonoscopy. This study aimed to determine the effect of the colonoscopist and other factors on advanced ADR and to define the correlation of advanced and nonadvanced ADRs among colonoscopists.
Methods: An observational study of a cohort of patients undergoing first-time colorectal cancer screening colonoscopy was conducted. Patient characteristics and colonoscopic findings were collected. Adenoma, advanced adenoma, and nonadvanced ADRs were calculated. Logistic regression was used to determine variable effects on advanced adenoma detection, and Spearman's rank-order correlation was used to evaluate the relationship between advanced and nonadvanced ADRs.
Results: A total of 1,944 patients had first-time screening colonoscopies by 14 colonoscopists. All colonoscopists had adequate (>20%) ADRs. The variability in the colonoscopist ranges of detection was 22.22 to 44.66% for adenomas and 2.00 to 18.18% for advanced adenomas. Logistic regression showed that increasing patient age (odds ratio (OR) 1.16 per 5-year increase, 95% confidence interval (CI) 1.05-1.28, P=0.008) and male gender (OR 2.15, 95% CI 1.51-3.06, P<0.0001) were variables associated with advanced adenoma detection. Colonoscopists were significantly different in detecting advanced adenomas by random effects model (P=0.002), adjusting for patient age, gender, race, year of colonoscopy, gastroenterology fellow participation during colonoscopy, and nonadvanced adenomas. Spearman's rank-order correlation coefficient of -0.42 (95% CI -0.77 to 0.14, P=0.13) was not significant and showed no correlation between advanced and nonadvanced adenoma detection by the group of colonoscopists.
Conclusions: Advanced ADR is variable among colonoscopists with acceptable ADRs. Colonoscopists' advanced ADRs are independent of their nonadvanced ADRs.