Digestive Diseases and Sciences

, Volume 58, Issue 7, pp 1856–1862

Can the Adenoma Detection Rate Reliably Identify Low-Performing Endoscopists? Results of a Modeling Study

  • Sameer D. Saini
  • Philip Schoenfeld
  • Sandeep Vijan
Original Article

Abstract

Background

Experts have stated that adenoma detection rates (ADR) of individual endoscopists should be measured to assess colonoscopy quality.

Aim

The purpose of this study was to quantify the reliability of the ADR as a quality marker.

Methods

We simulated a population of endoscopists and patients using published data on adenoma prevalence and adenoma miss rates. For each endoscopist, the ADR was calculated. The proportion of ADR variance attributable to endoscopist and the area under the ROC (AUROC) curve for low-performing endoscopists (lowest quartile or decile) were also calculated.

Results

In the base-case analysis (200 patients per endoscopist, miss rate 22 %, adenoma prevalence 24 %), only 13 % of ADR variance was attributable to endoscopist performance (AUROC up to 0.73). An ADR cutoff of <16.5 % identified approximately half of endoscopists in the lowest performance decile (test sensitivity = 53 %), but most (79 %) of the endoscopists identified by this cutoff were NOT low performers (i.e., false positives). In sensitivity analysis, increasing the number of patients per endoscopist, reducing the variance of adenoma prevalence between endoscopists (i.e., performing case-mix adjustment), and increasing the variance in performance between endoscopists all improved ADR test characteristics (AUROC up to 0.88). However, regardless of assumptions, a substantial proportion of endoscopists would be misclassified if a simple ADR cutoff were utilized.

Conclusions

The ADR has limited reliability as a quality marker under real-world assumptions. Simple cutoffs are likely to either be insufficiently sensitive or have high false positive rates. Future studies should identify alternative means for assessing endoscopist performance.

Keywords

Quality improvement Colonoscopy Adenoma detection rate 

Abbreviations

ADR

Adenoma detection rate

CRC

Colorectal cancer

AUROC

Area under receiver operating characteristic

Copyright information

© Springer Science+Business Media New York (Outside the USA) 2013

Authors and Affiliations

  • Sameer D. Saini
    • 1
    • 2
  • Philip Schoenfeld
    • 1
    • 2
  • Sandeep Vijan
    • 1
    • 3
  1. 1.Veterans Affairs Center for Clinical Management ResearchVeterans Affairs Medical CenterAnn ArborUSA
  2. 2.Division of GastroenterologyUniversity of Michigan Medical SchoolAnn ArborUSA
  3. 3.Division of General MedicineUniversity of Michigan Medical SchoolAnn ArborUSA

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