Adenoma detection rate: the real indicator of quality in colonoscopy

Completion rate is the most commonly used index of quality in colonoscopy, and yet a complete examination is not necessarily a good examination. The ability to detect and treat adenomas is an important component of endoscopic skill, because many colonoscopies are performed for this express purpose. Adenoma detection rate is rarely reported, although it seems to depend on the time taken for withdrawal. The literature suggests that adenomas should be detected in approximately 25 percent of men and 15 percent of women older than age 50 years. We have reviewed the adenoma detection rates of six colorectal surgeons to provide insight into the range of adenoma detection rates and the factors that influence them.

A prospective departmental colonoscopy database was queried. Colonoscopy completion rates, adenoma detection rates, and times of insertion and withdrawal were noted and stratified by the six staff colonoscopists. Adenoma detection rates were tabulated for the four common indications for colonoscopy.

Each staff endoscopist performed >250 examinations per year and had performed >1,000 total examinations. Although completion rates are fairly uniform (mean, 96.5 (range, 94.8-97.9) percent), there is a wide range of ADR, especially when adenomas are common (polyp or cancer surveillance; range, 14.2-27.4 percent). With the exclusion of one outlier staff, regression of withdrawal time against adenoma detection rate produced an r(2) of 0.975 (P = 0.0016).

Adenoma detection rate is independent of completion rate as a colonoscopy quality indicator. There is a wide range of adenoma detection rates among experienced colorectal surgeons. Colonoscopists need to be aware of their adenoma detection rate.