Fellow involvement may increase adenoma detection rates during colonoscopy.

Background: Adenoma detection rate (ADR) is increasingly used as a quality indicator for screening/surveillance colonoscopy. Recent investigations to identify factors that affect ADR have focused on the technical aspects of the procedure or the equipment.

Objective: To assess whether gastroenterology (GI) fellow participation during colonoscopy affects ADR.

Methods: This is a retrospective study of data prospectively collected on 309 patients enrolled in a different study not involving polyp detection. In total, 126 colonoscopies were performed by a GI attending alone, and 183 by a GI fellow supervised by one of the same four GI attendings.

Results: The ADR was significantly higher when a fellow was involved (37% vs 23%, P < 0.01), as was the total number of adenomas detected (0.56 per patient vs 0.30 per patient, P < 0.05). The percentage of patients with two and three or more adenomas was also higher for fellows versus attendings alone (13.1% vs 5.6%, and 6% vs 1.6%, respectively; P < 0.05), though there was no difference in the detection of advanced adenomas (7.1% vs 5.6%, P = 0.16). The adenomas detected when fellows participated were smaller (mean size 4.4 mm vs 5.8 mm, P < 0.05), and more likely to be sessile (80.6% vs 64.9%, P < 0.05). There were no significant differences in the age, gender, indication for colonoscopy, or procedure time for the two groups.

Conclusions: In this retrospective study, fellow involvement in colonoscopy may increase not only the ADR, but also the detection of more subtle adenomas. Further investigation into whether this is a "fellow effect," or simply a matter of more efficient visual scanning and recognition with two people, should be considered.