Defining Benchmarks for the Adenoma per Colonoscopy Quality Metric: Presidential Poster

Abstract

Purpose: The adenoma detection rate (ADR), defined as the proportion of screening colonoscopies where at least one adenoma is found, is currently the prime surrogate measure of colonoscopy performance quality. Minimum ADR targets in average-risk individuals are 25% for men and 15% for women. Unanswered questions remain about the optimal method for measurement of adenoma detection. The mean number of adenomas per colonoscopy (APC) is thought to be less prone to corruption than the ADR and provide a more comprehensive assessment of quality. However, the minimum benchmarks for this metric are unknown. The aim of this study was to define minimum detection benchmarks for the number of adenomas per screening colonoscopy quality metric. Methods: We performed a retrospective review of a prospectively updated database at a University hospital and associated ambulatory surgery center endoscopy units. Reports of screening colonoscopies performed by 20 attending gastroenterologists between 1/1/1999 and 4/30/2012 were reviewed. Colonoscopies performed on patients 50 years or older were included. ADR was defined as the proportion of screening colonoscopies in which at least one adenoma was detected. The mean number of adenomas per screening colonoscopy (APC) was defined as the total number of adenomas detected divided by the number of screening colonoscopies. Pearson correlation coefficient was calculated to evaluate the association of ADR and APC. Linear regression was used to model the relationship between the two rates and to derive mean APC rates which correspond to ADR of 25% in men and 15% in women, respectively. Results: A total of 7,434 screening colonoscopies were included. The screening ADR and APC for each endoscopist are shown in Table 1. The ADRs ranged from 15.7% to 46.2% (2.9-fold difference), while APCs ranged from 0.2 to 1.08 (5.4-fold difference). The screening ADR and APC were significantly correlated (R=0.91, p<0.0001). For males, ADR of 25% corresponded to APC of 0.46 (95% CI 0.35-0.57); for females, ADR of 15% corresponded to APC of 0.20 (95% CI 0.13-0.27). Additional screening ADR-APC correlates are detailed in Table 2.Table 1: Endoscopist-level screening ADR and APCTable 2: Screening ADR-APC correlates (males and females combined)Conclusion: The screening ADR and APC are very strongly correlated. We propose minimum screening APC detection benchmarks of 0.50 for males and 0.20 for females.