Variation in polyp detection rates at screening colonoscopy

Thomas F. Imperiale, Elizabeth A. Glowinski, Beth E. Juliar, Faouzi Azzouz, David F. Ransohoff

Research output: Contribution to journalArticle

109 Scopus citations


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 ≥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.

Original languageEnglish (US)
Pages (from-to)1288-1295
Number of pages8
JournalGastrointestinal endoscopy
Issue number7
StatePublished - Jun 1 2009


ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Gastroenterology

Cite this

Imperiale, T. F., Glowinski, E. A., Juliar, B. E., Azzouz, F., & Ransohoff, D. F. (2009). Variation in polyp detection rates at screening colonoscopy. Gastrointestinal endoscopy, 69(7), 1288-1295.