The Secondary Quality Indicator to Improve Prediction of Adenoma Miss Rate Apart from Adenoma Detection Rate

Adenoma detection rate (ADR) cannot distinguish between endoscopists who detect one adenoma and those who detect ≥2 adenomas. Hypothetically, adenoma miss rate (AMR) may be significant for endoscopists with high ADRs who examine the rest of colon with less care after detecting first polyp. Our objective was to evaluate other quality indicators plus ADR vs. ADR alone in prediction of AMR.

We conducted a cross-sectional study of asymptomatic participants aged 50-75 years who underwent back-to-back screening colonoscopies by four faculty endoscopists. Each round of colonoscopy was performed by two of the endoscopists in a randomized order. During each round of colonoscopy, all detected polyps were removed. The second endoscopist was blinded to the results of the first. The total number of adenomas per positive participant (APP), the total number of adenomas per colonoscopy (APC), the additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and ADR were calculated for prediction of AMR.

In all, 200 participants underwent back-to-back colonoscopies. There were no significant differences in ADRs of four endoscopists (44, 50, 54, and 46%). APPs were 1.91, 2.12, 2.19, and 2.43. APCs were 0.84, 1.06, 1.18, and 1.12. ADR-Plus were 0.40, 0.56, 0.64, and 0.66, respectively. AMRs differed significantly between the endoscopists (36, 27, 21, and 13%; P=0.01). There was no correlation between ADR and AMR (r=-0.25; P=0.75). Whereas APP exhibited a strong inverse correlation with AMRs (r=-0.99; P<0.01). APC and ADR-Plus appeared to be inversely correlated with AMR, however this was not statistically significant (r=-0.82; P=0.18 and r=-0.93; P=0.07, respectively).

Among high-ADR endoscopists, AMRs still varied. APP may be a promising secondary indicator for distinguishing between the one-and-done polyp endoscopist and the meticulous endoscopist. The evaluation of influence of new metrics on colorectal cancer (CRC) prevention requires a larger population-based study.