Colonoscopies performed by surgeons and other endoscopists were associated with lower adenoma detection rates compared to those done by gastroenterologists, according to a meta-analysis.

In a systematic review of 36 studies, adenoma detection rates during colonoscopy were 19% lower with surgeons (OR 0.81, 95% CI 0.74-0.88) and 9% lower with family physicians, general practitioners, and internists combined (OR 0.91, 95% CI 0.87-0.96), reported Nauzer Forbes, MD, MSc, of the University of Calgary in Canada, and colleagues in Clinical Gastroenterology and Hepatology.

In addition, colonoscopies performed by surgeons and other endoscopists were associated with lower cecal intubation rates, and higher rates of both adverse events and colorectal cancer following colonoscopy, they noted.

“These findings could be related to differences in training, credentialing standards and procedure volume across specialities,” Sonia Kupfer, MD, of the University of Chicago, told MedPage Today.

“While there are limitations such as heterogeneity between observational studies, the results underscore the importance of measuring colonoscopy quality and targeted quality improvement for low performers,” added Kupfer, who was not involved with the research.

“Gastroenterology training programs typically place emphasis on early exposure to high case volumes followed by consistent honing of skills throughout training,” the authors said. “In contrast, endoscopy training in surgical residency programs generally occurs via massed learning in blocks, ultimately resulting in lower overall exposure.”

Colonoscopies not only have an important function in premalignant lesion screening and detection, but also in resection, the authors noted. With colorectal cancer attributed to more than 50,000 U.S. deaths in 2020, the safety and effectiveness of colonoscopies become even more significant to sustain.

Differences in training recommendations differ by countries as well, the authors added. The U.K. Joint Advisory Group on GI Endoscopy has a minimum of 200 colonoscopies recommended for certification, compared to the American Board of Surgery’s minimum of 50.

The group analyzed data on 3,500,832 colonoscopies performed among observational studies published from 2003 to 2020. Studies needed to involve adult colonoscopies, include a colonoscopy performance comparison on physicians or specialists, and report on at least one key colonoscopy indicator, in this case adenoma detection rate.

“[Adenoma detection rate] has been inversely associated with the risk of post-colonoscopy colorectal cancer (PCCRC), defined as any new [colorectal cancer] detected beyond 6 months of a colonoscopy in which no cancer was diagnosed,” the authors wrote.

The primary outcome was adenoma detection rate between gastroenterologists and surgeons. Secondary outcomes included adenoma detection rates between gastroenterologists and “other endoscopists,” as well as associations between any specialty and other outcomes, such as cecal intubation rate, PCCRC, and adverse events.

There were 11 studies assessing cecal intubation rates, four studies comparing surgeon-performed colonoscopies to those by other endoscopists, 15 studies comparing gastroenterologist-performed colonoscopies to surgeon-performed colonoscopies, eight studies comparing PCCRC rates by specialties, and 15 studies comparing adverse events (colonic perforation) from endoscopy specialists.

Compared to endoscopies performed by gastroenterologists, colonoscopies performed by surgeons were associated with decreased cecal intubation rates (OR 0.76, 95% CI 0.63-0.92). Colonoscopies done by other endoscopists were associated with increased PCCRC rates (OR 1.23, 95% CI 1.14-1.33) and perforation rates (OR 3.02, 95% CI 1.65-5.51).

“Given that colonoscopy is a limited resource in some areas, efforts to improve quality are critical regardless of endoscopists’ specialities to ensure all patients benefit from life-saving screening exams,” Kupfer said.

Limitations of this study included the use of observational design with a greater risk for bias, unmeasured confounders, and potentially misclassified procedural codes, the authors acknowledged.

Forbes’ group also noted that the certainty in their estimates according to GRADE was low, but “nevertheless, our results represent meaningful findings that are immediately relevant to clinical practice worldwide.”

“It is important to note for all endoscopists, but particularly for non-gastroenterologists, that reliance on completion of a training program and current credentials does not guarantee high-quality performance, again stressing the need for quality assurance and improvement efforts,” the authors wrote.