It is always good to revisit fundamentals, and it is especially useful now given the public health emergency has generated staff turnover at many endoscopy units across the country. So, let’s talk about calculating Screening Colonoscopy Adenoma Detection Rate (ADR).
True or False
ADR is a proportional measure.
True. ADR is a proportional measure in which a score is derived by dividing the number of cases that meet a criterion for quality (the numerator) by the number of eligible cases within a given time frame (the denominator) where the numerator cases are a subset of the denominator cases. The definition of ADR is the percentage of patients age 50 years or older with at least one conventional adenoma or colorectal cancer detected during screening colonoscopy.
Because we do not know if the cases not meeting the numerator are patients with a normal colonoscopy or patients for which a lesion was missed, ADRs are not typically seen close to 100%. To provide some context, when we look to the GIQuIC clinical benchmarking registry, in which over 4,500 endoscopists across the country participate, the average ADR looking at January through September 2021 is 40.9% (171,872/420,242).
Remediation for low-level providers should be employed if ADR is less than 30% male, 20% female, or 25% comingled gender. Although it is good to keep in mind that, statistically speaking, on average, for each 1% increase in ADR, there is a 3% decrease in the risk of CRC.(1) So, patients benefit when all colonoscopists’ ADRs continue to increase.
True or False
The denominator for ADR is patients who underwent screening colonoscopies with polypectomies.
False. The denominator for ADR is patients 50 years of age or older for which the primary indication of a colonoscopy is screening when the procedure is performed to detect polyps/lesions in the absence of signs, symptoms, or personal history of colon neoplasia, even if during the screening colonoscopy polyps are found, removed or biopsied. Simply put, the ADR denominator is all patients aged 50 or older receiving a screening colonoscopy regardless of findings.
True or False
The denominator for ADR should include first-time screens only.
False. While this was true when ADR was first introduced, today ADR can include patients who had a negative screen 10 years prior.
True or False
Patients aged 45 to 49 years undergoing screening colonoscopy should be included in the denominator for ADR.
False. In May 2021, the US Preventative Services Task Force finalized its recommendations relative to colorectal cancer screening, which included the Grade B recommendation to screen for colorectal cancer in adults aged 45 to 49 years. A question on GI healthcare teams’ minds is what impact this recommendation has on the specifications for colorectal cancer screening-related measures, such as for ADR. Expert consensus at this time is this recommendation should not direct any immediate action relative to updating measure specifications. Research is underway but for now, the specifications for colorectal cancer screening-related measures are anticipated to remain the same. ASGE will certainly keep you updated on this point.
Where can I learn more?
(1) Corley DA, Jensen CD, Marks AR, et al. Adenoma detection rate and risk of colorectal cancer and death. N Engl J Med 2014;370:1298-306.