In an analysis of routine colonoscopies performed for average-risk patients, physician assistants (PAs) performed the procedure on par with their gastroenterologist counterparts, according to a study published in the Journal of the American Academy of Physician Assistants.

Researchers analyzed routine screening colonoscopies for 597 of 743 consecutive patients from July 2015 to June 2016. Patients with an advanced risk of colorectal cancer, those who exhibited symptoms or had a family history of bowel cancer, and those who inadequately prepared for the procedure were excluded. The colonoscopies were performed by 7 gastroenterologists, 5 PAs, and 32 gastroenterology (GI) fellows from St. Louis University and Washington University.

Endoscopic assistance was permitted for the group of GI fellows, but instances in which a PA required assistance from a gastroenterologist were excluded from the final results. Physicians were permitted to provide their input in the interpretation of endoscopic findings on cases performed in their entirety by PAs.

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Researchers collected data on intubation time, withdrawal time, bowel prep quality, colon segment reached, and total number of polyps; polyps were further classified by an independent pathologist into adenomas, advanced adenomas, or cancer.

The physicians in the study had a median of 15.5 years of experience whereas the PAs had a median of 10.8 years. Overall, cecal intubation was successful in 98.5% of patients with a mean intubation time of 9.9 minutes. Adenomas were detected in 44.6% of patients, with 13.4% patients having 1 or more adenomas larger than 1 cm. Only 1 screening colonoscopy revealed colorectal cancer.

In the groups of clinicians with ≤5 years or 6 to 15 years of endoscopy experience, no statistically significant difference was found in mean intubation time between PAs and physicians; however, the group of PAs with >15 years of experience had shorter mean intubation times than gastroenterologists with similar experience (7.5 min vs 15.6 min). 

Colonoscope withdrawal time was >6 minutes for both attending gastroenterologists and for PAs. No statistically significant differences in adenoma detection rates were identified when compared based on years of experience.

Colonoscopy performance was also examined by provider type as opposed to years of experience. PAs performed significantly better than GI fellows in intubation time (7.8 min vs 13.2 min) and had a notably shorter withdrawal time (9.6 min vs 11.5 min, respectively). No significant difference was found between the intubation time of PAs and attending gastroenterologists (7.8 min vs 8.8 min).  PAs, GI fellows and attending gastroenterologists performed comparably in adenoma detection (46.7%, 43.5%, and 44.2%, respectively).

Since cases in which GI fellows requiring assistance with cecal intubation were included in the study, but cases in which PAs requiring assistance were excluded from analysis, the study authors noted that the comparison of cecal intubation rates between PAs and fellows is compromised.

This finding suggests that PAs can play an integral role in increasing screening for colorectal cancer, especially in areas with a lack of resources. Fecal testing is a less invasive and more widely available alternative to colonoscopies for patients of average risk, but the disparity in access remains for patients who test positive and ultimately require a colonoscopy as well, according to the study authors.

“PAs and nurse practitioners might be particularly well positioned to perform as endoscopists in order to extend our ability to perform screening colonoscopy in resource-poor settings,” the study authors concluded.


Fejleh MP, Shen C, Chen J, Bushong J, Dieckgraefe, B, Sayuk G. Quality metrics of screening colonoscopies performed by PAs. JAAPA. 2020;33(4):43-48.