Narrow band imaging vs. high definition colonoscopy for detection of colorectal adenomas in patients with positive faecal occult blood test: a randomised trial.

Background: The impact of narrow band imaging in improving the adenoma detection rate in a screening scenario is still unclear.

Aim: To evaluate whether narrow band imaging compared with high definition white light colonoscopy can enhance the adenoma detection rate during screening colonoscopy.

Methods: Consecutive patients presenting for screening colonoscopy were included into this study and were randomly assigned to the narrow band imaging group (Group 1) or standard colonoscopy group (Group 2). Primary end point was the adenoma detection rate and secondary aim was the detection rate of advanced adenomas.

Results: Overall, 117 patients were allocated to Group 1 and 120 to Group 2. Both the adenoma detection rate and the detection rate of advanced adenomas were not significantly different between the two groups (respectively, 52.1% vs. 55%, RR=0.95, 95% CI 0.75-1.20; 32.5% vs. 44.2%, RR=0.74, 95% CI 0.53-1.02). No significant difference between the proportions of polypoid and flat adenomas was found. Male gender, no prior history of screening, and endoscopist's adenoma detection rate were independent predictive factors of higher advanced adenoma detection rate.

Conclusions: In a screening scenario, narrow band imaging did not improve the adenoma nor advanced adenoma detection rates compared to high definition white light colonoscopy.