Improving measurement of the adenoma detection rate and adenoma per colonoscopy quality metric: the Indiana University experience.

BACKGROUND

The adenoma detection rate (ADR) is a validated marker of colonoscopy quality. However, the optimal measurement method is unclear.

OBJECTIVE

The aims of our study were to (1) define benchmarks for the number of adenomas per screening colonoscopy (APC) quality metric; (2) study the association between ADRs for screening, surveillance, and diagnostic indications; and (3) explore the association of the screening ADR with an overall ADR inclusive of all colonoscopy indications.

DESIGN

Retrospective study.

SETTING

University hospital and associated ambulatory surgery center endoscopy units.

PATIENTS

Patients aged ≥50 years who underwent colonoscopy for screening, surveillance, or diagnostic indications by 20 endoscopists between January 1, 1999 and April 30, 2012.

INTERVENTION

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

ADR, APC for screening, surveillance, and diagnostic indications.

RESULTS

A total of 21,766 colonoscopies were included. The indication was screening in 7434 (34.2%), surveillance in 8338 (38.3%), and diagnostic in 5994 (27.5%). The screening ADRs and APCs were significantly correlated (R = 0.91; P < .0001). For men, an ADR of 25% corresponded to an APC of 0.46 (95% confidence interval [CI], 0.35-0.57); for women, an ADR of 15% corresponded to an APC of 0.20 (95% CI, 0.13-0.27). Overall, the ADR stratified by colonoscopy indication was highest for surveillance, followed by screening, then diagnostic. For men, a screening ADR of 25% corresponded to a surveillance ADR of 31.9% (95% CI, 24.8%-38.9%); for women, an ADR of 15% corresponded to a surveillance ADR of 24.3% (95% CI, 18.3%-30.5%). The corresponding diagnostic ADRs were 17.0% (95% CI, 12.4%-21.6%) and 15.4% (95% CI, 11.5%-19.3%), respectively. There was significant correlation between screening ADR and an overall ADR inclusive of all colonoscopy indications.

LIMITATIONS

External generalizability, retrospective design.

CONCLUSION

We propose minimum screening APC detection benchmarks of 0.50 for men and 0.20 for women. ADRs for screening, surveillance, and diagnostic colonoscopy are correlated and can be used to derive a simplified overall ADR inclusive of all colonoscopy indications.