Variation in polyp detection rates at screening colonoscopy

Gastrointest Endosc. 2009 Jun;69(7):1288-95. doi: 10.1016/j.gie.2007.11.043.


Background: Variation in polyp detection among endoscopists has been used to justify the need for establishing quality standards for colonoscopy performance.

Objective: To measure variation in polyp detection rates (PDRs) among endoscopists who perform screening colonoscopy and to identify associated factors.

Design: Cross-sectional analysis of summary-level data.

Setting: Endoscopy practices in central Indiana.

Subjects: Twenty-five endoscopists and their patients.

Main outcome measurements: Mean procedure time (MPT); proportions of patients with any polyp, any adenoma, any polyp > or =1.0 cm, and multiple adenomas; and variation in PDRs and identification of outliers. Multiple linear regression analysis identified factors that accounted for the variation in PDRs.

Results: A total of 2664 screening colonoscopies (1108 women and 1556 men) were performed. The mean patient age was 59 years; the mean proportion of women was 42%; the MPT was 17.1 minutes. Adenoma detection rates ranged from 7% to 44% (P < .001) and from 0% to 13% for large polyps, which was not statistically significant (P = .07). For all polyp categories, only 1 to 3 high outlier endoscopists (ie, higher than mean PDRs) were identified. Models that included the number of procedures, mean age, percentage of women, and MPT accounted for 36% to 56% of the variation in PDRs. In all models, only MPT was significantly associated with PDRs.

Limitations: Whether each endoscopist's cohort was at comparable risk for colorectal neoplasia was uncertain. In comparison with individual-level data, analysis of summary-level data is limited.

Conclusions: PDRs vary widely among endoscopists, although only a few (high) outliers were identified. Variation in PDRs was associated only with MPT. Further research is needed to determine the clinical importance of and reasons for this variation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenoma / diagnosis*
  • Clinical Competence
  • Colonic Polyps / diagnosis*
  • Colonoscopy / standards*
  • Colorectal Neoplasms / diagnosis*
  • Cross-Sectional Studies
  • Early Detection of Cancer
  • Female
  • Humans
  • Male
  • Mass Screening
  • Middle Aged
  • Quality of Health Care
  • Retrospective Studies