Screening colonoscopy is performed by endoscopists from multiple specialties, primarily gastroenterologists and colorectal surgeons.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services Policy
When endoscopists meet quality standards, colonoscopy reduces colorectal cancer incidence and mortality.
When quality factors such as adenoma detection rate (ADR), withdrawal time and bowel preparation are not achieved, evidence shows that the risk of interval colorectal cancer development may increase.
Recent literature also suggests that the specialty of the endoscopist performing the procedure can predict colonoscopy quality. One study found that patients who have negative colonoscopies performed by a specialist other than a gastroenterologist have an increased incidence of interval colorectal cancer development and a subsequent increase in mortality.
These data prompted researchers in Cleveland Clinic Digestive Disease & Surgery Institute’s Department of Colorectal Surgery to investigate quality benchmarks in the two specialties — gastroenterology and colorectal surgery — that perform colonoscopies at the institution.
“As colorectal surgeons who perform many colonoscopies, we wanted to find out if we were meeting quality metrics as well as our gastroenterology colleagues are,” says Michael Valente, DO, FACS, FASCRS, a staff surgeon in the Department of Colorectal Surgery.
Study criteria and results
The study looked at screening colonoscopies performed at Cleveland Clinic between January 2016 and June 2017. The criteria for patient inclusion were age 50 or older, absence of symptoms, no colorectal cancer or polyps previously identified with colonoscopy, and/or having a first colonoscopy. The quality parameters considered were ADR (overall, male and female), cecal intubation rate, total examination time, withdrawal time, intra-procedural complications and quality of bowel preparation.
A total of 15,276 patients met the criteria; mean patient age was 60.3 years and 52.4% of the study cohort were female. Of the colonoscopies performed, 11,339 (74.2%) were done by 73 gastroenterologists (the GI group) and 3,937 (25.7%) by 19 colorectal surgeons (the CRS group).
In comparing the colonoscopy quality factors between the two groups, the study found the following outcomes:
- No differences in cecal intubation rate
- Significantly shorter total examination time and withdrawal time in the GI group
- Overall ADR: 31% in gastroenterologists compared to 25.3% in colorectal surgeons (female ADR was 25.3% vs. 20.8% and male ADR was 37.7% vs. 30.2%)
- Bowel preparation was graded lower in the colorectal surgeon group.
- No statistical difference in the complication rate was found between the two groups.
While both groups met national quality benchmarks for ADR (30% or higher for men and 20% or higher for women), the GI group’s higher rate is significant. “It shows that we [colorectal surgeons] can do even better and should strive for continued improvement,” says Dr. Valente.
Investigators performed a subgroup analysis comparing patients with an adenoma found at screening to those who didn’t have any adenoma detected. Patients with an adenoma were significantly older and more likely to be male. This group had significantly longer examination and withdrawal times. No difference in bowel preparation was found in the two patient groups but the trend was toward lower quality in the CRS group.
Improving colonoscopy outcomes
The study confirmed the importance of bowel preparation for successful outcomes: The inferior overall bowel preparation in the CRS group may partly explain the lower ADR rate in this group. Evidence shows that poor or inadequate bowel preparation is associated with lower adenoma detection and polypectomy rates.
“We believe that bowel preparation is a critical factor in colonoscopy quality,” Dr. Valente says. “We use a standard bowel preparation method throughout the institution and have found that a split dose preparation increases quality, which should increase ADR. Patient education is key to achieving this goal.”
Endoscopists also should pay attention to withdrawal time. A withdrawal time of six minutes or longer is recommended by the American Society of Gastrointestinal Endoscopy and the American College of Gastroenterology Task Force on Quality in Endoscopy. One study reported that longer withdrawal times were associated with higher adenoma detection rates; withdrawal time greater than eight minutes was associated with the lowest risk of developing interval colorectal cancer.
Among Cleveland Clinic endoscopists, the withdrawal time was 10.1 minutes in the GI group and 10.6 minutes in the CRS group. “The more time you spend in withdrawal, the more adenomas you are likely to find,” says Dr. Valente. “This is the most important time during the procedure.”
As a result of this study, Cleveland Clinic has implemented a quality improvement program that includes benchmarking each endoscopist’s performance and sharing the data on a quarterly basis.
“We believe that oversight, more than specialty, can improve colonoscopy quality,” Dr. Valente says. “Institutions need to audit each endoscopist’s data, regardless of specialty. If an institution doesn’t collect data, each endoscopist should keep their own data and make adjustments to improve patient outcomes.”