Evaluating adenoma detection and miss rates in tandem colonoscopy: Limitations of surrogate quality indicators

The adenoma detection rate (ADR) is a key quality metric in colonoscopy. However, it may not accurately reflect the true number of adenomas and requires pathological evaluation of all detected polyps. The adenoma miss rate (AMR), which quantifies adenomas missed during colonoscopy, may provide a more comprehensive measure of colonoscopy quality.

To evaluate the effectiveness of ADR and selected surrogate quality indicators (SQIs) in reflecting AMR.

In this prospective, cross-sectional, multicenter study, we analyzed asymptomatic individuals aged 50-72 years who underwent tandem colonoscopies using a split-dose bowel preparation regimen. Colonoscopies were performed by 7 endoscopists (experts with >10 years of experience from different institutions) over the last 5 years. Consecutive colonoscopies were performed by the same endoscopist under identical conditions. During the 2nd colonoscopy, polyps missed during the 1st colonoscopy were documented. All removed polyps were subsequently evaluated by a pathologist.

We analyzed colonoscopy data from 356 patients (182 (51.12%) males and 174 (48.88%) females), representing a total of 712 colonoscopies. Adenomas were confirmed in 221 participants (62%). The number of adenomas missed during the 1st colonoscopy was 88, whereas 60 participants had at least 1 missed adenoma. No statistically significant variation among endoscopists was observed in the polyp detection rate (range: 48.000-64.000%, p = 0.658) or the adenoma detection rate (range: 54.000-74.000%, p = 0.151). Adenomas per positive participant ranged from 1.05 to 1.89, and adenomas per colonoscopy ranged from 0.70 to 1.44 (p = 0.063). The overall pooled lesion-level AMR was 20.046%. None of the SQIs showed a significant association with AMR (p > 0.050 for all comparisons). Although SQIs and ADR varied among endoscopists, no statistically significant variation in AMR was observed among the 7 endoscopists (p > 0.050).

A high ADR alone does not ensure a lower AMR in tandem colonoscopy for colorectal cancer screening. In this limited provider-level sample, no statistically significant association was observed between SQIs and AMR.