2012-01-27 19:40:46 UTC

Proposed Quality Measures for CRC Screening Are Effective

Jan. 27, 2012


Douglas O. Faigel, MD, AGAF

Professor of Medicine, Mayo Clinic College of Medicine, Scottsdale, AZ

The purpose of a screening colonoscopy is to prevent colorectal cancer (CRC). It is intuitive that a high-quality exam will prevent more cancers than a low-quality one. As endoscopists, we all know what a high-quality colonoscopy is: a complete exam to the cecum with careful examination of the mucosa and removal of all neoplastic lesions. Using this common-sense definition, it is not hard to come up with the most important quality metrics for colonoscopy: cecal intubation and removal of adenomatous polyps. It has been shown that there can be considerable variation in the rates of cecal intubation and adenoma removal among colonoscopists. So without going any further, we can state with high certainty that metrics can distinguish high-performing colonoscopists from low-performing, and we could stop our debate right here and declare victory. But Philip Schoenfeld, MD, MSEd, MSc (Epi), and skeptics like him (and I count myself in that group) would object. After all, the point of all of these colonoscopies is to improve outcome. We should demand that quality measurement also lead to improved outcome.

And it does.

Focusing on those two most important metrics — completion and polyp removal — we need to ask: do higher completion rates or higher polypectomy (adenoma removal) rates correlate with protection from CRC? The answer is: yes they do. Two large population-based studies, one from Poland and the other from Canada, each documented that protection from colon cancer was associated with higher polyp removal rates. In the Polish study, 45,000 subjects underwent screening colonoscopy by 186 endoscopists. Patients who were examined by endoscopists with adenoma detection rates less than 20 percent had a 10- to 12-fold higher likelihood of having an interval CRC than if their endoscopist had an adenoma detection rate (ADR) of greater than or equal to 20 percent. 1 In the Canadian study of 14,000 patients, polypectomy rate was significantly associated with reduced interval right-sided colon cancer.2 In fact, polypectomy rates greater than 25 percent were associated with a greater than 50 percent reduction in right-sided cancer. And recall that there is a debate whether colonoscopy protects against right-sided colon cancer at all! The Canadian study also documented CRC protection when the colonoscopy completion rate was high.2

But we cannot consider quality measurement in a vacuum. It is not enough just to measure quality. We need to do something with it. We need a plan. We need a quality improvement program.

In the quality improvement program, we would use our metrics to identify poorly performing individuals and then institute an intervention to achieve improvement. You would measure, act and then measure again to gauge the success of the intervention. How can this be done for colonoscopy?

First of all, choose your measures. Cecal intubation and adenoma removal are likely to be the best, but each has issues. For cecal intubation, you need to define what that is. It should be defined by photography of the appendiceal orifice, ileocecal valve and cecal strap fold.3 In some units, the nurses and techs need to agree with the endoscopist that the cecum has been entered. You also need to define the denominator: all patients, all patients without obstruction, all patients without a poor prep, etc. Excluding a large number of patients can be problematic, so I recommend that you include all patients with a cecum. Very few patients have obstructing lesions. And if you are having a lot of poor preps, then that is a different problem.

For adenoma removal, you will have some choices. The ADR is the best studied measure and the one with most expert opinion backing it. This is the proportion of age-appropriate patients undergoing screening colonoscopy in whom at least one adenoma is found. Benchmark rates of 25 percent for men and 15 percent for women have been proposed and are achievable.3 A related measure is the number of adenomas per patient, which considers both how many patients have an adenoma and how many adenomas are found in each patient. This measure can be more difficult to use since it would require that every polyp be placed in a separate jar, and there are no established benchmarks. The main problem with ADR is that it is relatively difficult to measure. It is not available at the time of colonoscopy, and in most practices, some individual has to physically link the colonoscopy report to the pathology result. This can be cumbersome and potentially expensive.

There are surrogate measures for ADR. Some studies have used the polyp detection rate (polyp find rate) as a measure. I have been uncomfortable with this measure since the purpose of colonoscopy is to remove polyps, not just find them. This led us to examine the polyp removal rate (polypectomy rate) as a quality measure. We have found that polypectomy rate is highly correlated with ADR, and have proposed benchmarks of 40 percent in men and 30 percent in women.4 Polypectomy rate can be determined directly from the endoscopy report or potentially from administrative claims data. (In fact, the Canadian study that demonstrated a correlation between polypectomy rate and colon cancer prevention used claims data.) Polypectomy rate has been criticized as being prone to gaming: one could just biopsy insignificant lumps and call that a polypectomy. This could be guarded against by relatively infrequent audits of a sample of pathology reports.

Whatever measures you pick, you will need to share the results with your endoscopists. This should be done in a friendly, supportive, non-penalizing and (in most cases) anonymous way. Each colonoscopist should know their own data as well as how they compare to others in the group and against national benchmarks. Everyone should understand that the goal is to provide the best services to our patients. And don’t worry about lawsuits; quality improvement program data are not discoverable.

Just the act of sharing the results may result in improvement if the individual is receptive to feedback. A designated individual — a physician in the practice — should meet with the underperforming individual to discuss the metrics and explore reasons for underperformance. This should not be a confrontation, but done in a supportive, collaborative way focusing on patient care. If the problem is cecal intubation, looking at potential reasons and solutions can be beneficial. These include: poor preps (solution: institute split dose administration), a large percentage of women or those with pelvic surgery (use pediatric colonoscope), misidentification of the cecum (review cecal photography, obtain consensus with nurse/tech that the cecum has been reached), looping (consider external pressure, position change, use of water-fill technique). Inadequate polyp removal rate is usually due to a less-than-careful exam. In this case, the withdrawal time can be a useful tool. Withdrawal time is associated with adenoma detection.5 However, I no longer advocate its routine use since it is really just a surrogate measure, and you should be directly measuring ADR or polypectomy rate. But withdrawal time can be a useful improvement tool. Use a clock or a stopwatch to ensure that at least two minutes are spent in each of the four colonic segments (ascending, transverse, descending, sigmoid/rectum) to achieve at least an eight-minute withdrawal time. This protocol was associated with significant improvement in ADR.6 Also consider pairing the low-performing colonoscopist with a higher-performing one. This can be invaluable in demonstrating and reinforcing techniques for adequate examination such as looking behind folds and suctioning all pools of retained material.

In conclusion, the most important quality metrics are colonoscopy completion and adenoma removal. These are associated with prevention of CRC. They need to be used as part of a quality measurement and improvement program. When properly used, they will lead to improved patient outcomes.

Dr. Faigel is a consultant to Ethicon Endo-Surgery, Inc. He is the treasurer and chair of ASGE’s Budget and Finance Committee as well as chair of its investment and audit committees. Dr. Faigel is also a member of the board of trustees of the ASGE Foundation.

1. Kaminsky MF, Regula J, Kraszewska E, Polkowski M, Wojciechowska U et al. Quality indicators of colonoscopy and the risk of interval cancer. N Engl J Med 2010;362(19):1795-1803.
2. Baxter NN, Sutradhar R, Forbes SS, Paszat LF, Saskin R, Rabeneck L. Analysis of administrative data finds endoscopist quality measures associated with postcolonoscopy colorectal cancer. Gastroenterology 2011;140:65-72.
3. Rex DK, Petrini JL, Baron TH, Chak A, Cohen J, et al. Quality indicators for colonoscopy. Gastrointest Endosc 2006;63:S16-28. Am J Gastro 2006;101:873-85.
4. Williams JE, Le TD, Faigel DO. Polypectomy rate as a quality measure for colonoscopy. Gastrointest Endosc 2011 Mar; 73(3):498-506.
5. Barclay RL, Vicari JJ, Doughty AS, Johanson JF, Greenlaw RL. Colonoscopic withdrawal times and adenoma detection during screening colonoscopy. New Engl J Med 2006;355:2533-41.
6. Barclay RL, Vicari JJ, Greenlaw RL. Effect of a time-dependent colonoscopic withdrawal protocol on adenoma detection during screening colonoscopy. Clin Gastroenterol Hepatol 2008;6:1091-8.

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