Original article
Clinical endoscopy
Variation in polyp detection rates at screening colonoscopy

https://doi.org/10.1016/j.gie.2007.11.043Get rights and content

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.

Section snippets

Study design

We performed a retrospective, cross-sectional analysis of summary-level data from endoscopists performing screening colonoscopy for the Lilly Colorectal Cancer Prevention Program, which is a corporate-based program of colonoscopic screening established in 1995 by Eli Lilly and Company for its employees, retirees, and their dependents. Specific details about the program were previously described.13, 14, 15 All procedures were performed on average-risk asymptomatic adults, aged 50 years or older,

Results

From September 1995 through June 2001, 2925 persons underwent first-time screening colonoscopy by 46 endoscopists as part of the colorectal cancer prevention program. We excluded 21 endoscopists who performed fewer than 40 screening colonoscopies for the program during this time interval, along with their 261 patients, which resulted in a study sample size of 25 endoscopists and 2664 persons (1556 men and 1108 women) performing and undergoing screening colonoscopy, respectively.

The overall mean

Discussion

Herein, we describe variation in PDRs and adenoma detection rates among endoscopists performing screening colonoscopy. For any adenoma, detection rates varied from 7% to 44%, a greater than 6-fold difference. For large polyps, PDRs ranged from 0% to 13%, a result that was not statistically significant (P = .07). There were no endoscopists with detection rates lower than 1.5 times the interquartile range, because a box-plot analysis identified only 1 to 3 high outliers per polyp category.

In

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      ADR is another priority indicator for screening colonoscopy in asymptomatic, average-risk individuals, and the rationale behind the creation of this term was to minimize the variation among colonoscopists in the detection of adenomas [27–31]. The recommended targets for ADR based on screening colonoscopy studies are 25 % and 15 % in male and female patients, respectively, aged ≥ 50 years undergoing screening colonoscopy [26–31]. Despite the lack of CRC national screening programs, we proposed the ADR as a quality indicator that appeared relatively lower in our results (15 %) than that previously reported in international figures (15 %–25 %).

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    DISCLOSURE: All authors disclosed no financial relationships relevant to this publication. Grant support: NIH grant K24 DK 002756.

    See CME section; p. 1350.

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