Neither time of day, nor number of procedures performed by the clinician impacted adenoma detection rates in a large community-based setting, a study has shown.

Previously, mixed and scanty data on whether endoscopist fatigue correlates with colonoscopy quality in a community-based setting – where the majority of colonoscopies are performed – brought into question the link between a clinician’s detection rates and patient mortality rates due to interval cancers. Colorectal cancer is the second leading cause of cancer death in the U.S.

The most recent recommended adenoma detection rates – considered benchmarks of colonoscopic quality – are at or above 20% in men and at or above 30% in women , according to the American College of Gastroenterology.

A new study published online in Gastrointestinal Endoscopy, however, indicates that the endoscopists working in a large, integrated, community-based health care system exceeded those quality benchmarks.

Gastroenterologist Alexander T. Lee, MD , and his colleagues identified 126 gastroenterologists in the health system, Kaiser Permanente Northern California, who performed an average of six endoscopy procedures per day – 259,064 in all – between 2010 and 2013, including 76,445 screenings and surveillance colonoscopies. They found that per physician, adenoma detection rates for screening colonoscopy examinations averaged 28.9% and 45.4% for surveillance examinations. By patient gender, the average detection rates per screening were 34.8% for men and 24.0% for women; detection rates per surveillance, the rates were 51.1% for men and 37.8% for women.

After adjusting for confounders, the investigators analyzed each physician’s average adenoma detection rates in association with the time of day each GI procedure was performed, the number of GI procedures performed before each colonoscopy, and the level of complexity of any prior procedures performed at the time of the screening or surveillance colonoscopy. Dr. Lee and his coinvestigators also found that compared with morning examinations, afternoon colonoscopies were not associated with lower adenoma detection for screening examinations, surveillance examinations, or their combination (odds ratio for combination, 0.99; 95% confidence interval, 0.96-1.03). Additionally, neither the number of procedures performed before a given colonoscopy, nor a prior procedure’s complexity, was inversely associated with adenoma detection (OR for detection rates late in the day vs. first procedure of the day, 0.99; 95% CI, 0.94-1.04).

In systems where physicians have larger daily GI procedure loads, there could be an adverse impact on adenoma detection rates, wrote Dr. Lee and his coauthors, but they also noted that quality could similarly be diluted by a lower ratio of procedures to clinician, as well. Whether other demands on a physician’s time, such as other clinical procedures or office tasks, might adversely impact detection rates, Dr. Lee and his colleagues didn’t know because they measured only the colonoscopic screening and surveillance activities. “The reported lack of an association with time of day would argue against this being a substantial factor in [this] study,” they wrote.

“The fact that increased adenoma detection was found only for screening colonoscopy examinations raises the question of whether endoscopists were systematically more vigilant during screening procedures, although the higher observed adenoma detection rates for surveillance examinations suggest otherwise,” the investigators wrote.

None of the investigators listed had any relevant disclosures.

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