| # | Provider | Location | Score | ADR | Withdrawal Time | Cecal Intubation Rate | Cases / Year |
|---|
Why These Four Metrics?
Colonoscopy quality varies significantly between providers — and that variation has real consequences for patient outcomes. Research shows that patients of low-ADR endoscopists are up to 10× more likely to develop interval colorectal cancer (cancer diagnosed within 5 years of a negative colonoscopy) compared to patients of high-ADR endoscopists. The four metrics below are endorsed by the American Society for Gastrointestinal Endoscopy (ASGE), the American College of Gastroenterology (ACG), and the Multi-Society Task Force on Colorectal Cancer as the primary indicators of colonoscopy quality.
Adenoma Detection Rate
ADRADR is the percentage of screening colonoscopies in which at least one adenoma (precancerous polyp) is found. It is the single most important predictor of whether a colonoscopy will prevent colorectal cancer. An endoscopist who carefully inspects the colon lining, uses adequate withdrawal time, and flattens folds will detect more adenomas — and each 1% increase in ADR is associated with a 3% decrease in the risk of interval colorectal cancer.
Withdrawal Time
WTWithdrawal time is the time spent pulling the scope back out through the colon after reaching the cecum. This is when most polyps are found. Rushing the withdrawal phase is a major cause of missed lesions. Multiple studies have shown that endoscopists with withdrawal times under 6 minutes miss significantly more adenomas. A minimum of 6 minutes is required; high-quality endoscopists average 8–12 minutes on negative exams.
Annual Case Volume
VOLUMEVolume is a proxy for experience and skill maintenance. Like any procedural skill, colonoscopy competence correlates with how frequently it is performed. Higher-volume endoscopists have lower complication rates, higher cecal intubation rates, and typically better ADR. The ASGE recommends a minimum of 200 procedures to establish initial competency, with ongoing volume needed to maintain it.
Cecal Intubation Rate
CIRThe cecal intubation rate measures how often the endoscopist successfully reaches the cecum — the very end of the large intestine. A colonoscopy that doesn't reach the cecum is incomplete: the right colon, where many flat and serrated polyps are found, goes uninspected. Failure to intubate is caused by looping, anatomical difficulty, or inadequate technique. Photo documentation of the cecum is required for verification.
Who Is Licensed to Perform Colonoscopy in the US?
Gastroenterologists (MD / DO)
The primary specialty for colonoscopy. Gastroenterology fellowship (3 years post-residency) includes intensive endoscopy training with 140–200 required colonoscopies as a minimum. GI specialists perform the vast majority of colonoscopies in the US and have the highest average ADRs as a group.
Colorectal Surgeons (MD / DO)
Colorectal surgery fellowship includes colonoscopy training. Colorectal surgeons routinely perform diagnostic and therapeutic colonoscopies, particularly in patients with surgical conditions such as colorectal cancer, diverticular disease, or inflammatory bowel disease requiring operative management.
General Surgeons (MD / DO)
General surgery residency includes endoscopy training. General surgeons in rural or community settings often perform colonoscopies where subspecialist access is limited. Their privileges must be granted by the credentialing committee of each facility where they practice.
Internists & Family Medicine (MD / DO)
Historically, some internists performed colonoscopies. This is now rare in academic and urban settings but still occurs in underserved communities where access to GI specialists is limited. Competency must be demonstrated through case logs and outcomes data.
Nurse Practitioners (NP)
In select states with full practice authority, highly trained NPs have received colonoscopy privileges at specific institutions, typically in collaborative practice models with supervising gastroenterologists. This is not widespread but is expanding in rural health shortage areas.
Physician Assistants (PA)
PAs working in GI practices may be trained to perform colonoscopies under physician supervision in some states and institutions. As with NPs, formal credentialing and demonstrated competency are required. Several studies have shown that trained PAs can achieve quality metrics comparable to physician endoscopists.
How the Composite Score Is Calculated
Metric Weights
Score Legend
Key References
- Corley DA et al. Adenoma detection rate and risk of colorectal cancer and death. NEJM 2014;370:1298–1306.
- Rex DK et al. Quality indicators for colonoscopy. Gastrointest Endosc 2015;81:31–53.
- Barclay RL et al. Colonoscopic withdrawal times and adenoma detection during screening colonoscopy. NEJM 2006;355:2533–2541.
- ASGE/ACG Task Force on Quality in Endoscopy. Quality indicators for colonoscopy. Am J Gastroenterol 2006;101:873–885.
- Kaminski MF et al. Quality indicators for colonoscopy and the risk of interval cancer. NEJM 2010;362:1795–1803.