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What is Adenoma Detection Rate?

Most people who are at average risk for colon cancer will only have to undergo colonoscopy once every 10 years. It is extremely important that your gastroenterologist is thorough and diligent in performing the procedure.

An adenoma is a benign tumor or growth that is identified and can usually be removed during a colonoscopy. Most colon cancers develop from adenomatous polyps. If a benign adenoma is left to grow in the colon, it can become malignant over time.

Adenoma detection rate (ADR) is the widely accepted national benchmark on quality for screening colonoscopy. A physician’s adenoma detection rate is the proportion of individuals undergoing a complete screening colonoscopy who have one or more adenomas, or polyps, detected. When you are interviewing gastroenterologists to perform your colonoscopy, you should be looking for a physician with an ADR of at least 15 percent in women and 25 percent in men. Gastroenterologists take great pride in their ADR because it is a direct measure of the effectiveness of the colonoscopy that they offer. 

How is a high ADR related to a quality colonoscopy?
ADR is critical for a quality colonoscopy and for colon cancer prevention. Consider this statistic: for every 1 percent increase in a physician’s ADR, your risk of developing colon cancer over the next year decreases by 3 percent. Doctors who are extremely proficient at finding and removing precancerous polyps have patients who are less likely to get cancer.

Some Exceptions
It is important to keep a balanced perspective when choosing who will perform your colonoscopy. Even though you will be looking for a doctor with a high ADR, it may be helpful to consider the fact that patient demographics may affect ADR. A female gastroenterologist who sees mostly younger female patients may have a lower ADR than a doctor who sees mostly older male patients. This does not make her any less competent. The difference in ADR may say more about the patients the doctors see rather than the expertise of two gastroenterologists.

Withdrawal Time
A high ADR is often a sign of a gastroenterologist who spends a longer amount of time inspecting the large intestine. A colonoscopy is performed with a colonoscope that is passed through the rectum, and advanced until it stops near the appendix in the right colon. When the scope is fully inserted, the gastroenterologist will begin systematically inspecting the colon for polyps while slowly withdrawing the scope.

Doctors who are especially meticulous in their examinations will have a longer withdrawal time. Specialists who are slower and more methodical in their withdrawal time are more likely to find precancerous polyps and lesions, so you should look for a gastroenterologist with a withdrawal time of at least six minutes. When making a decision on who should perform your colonoscopy, you should feel confident to inquire both about a doctor’s adenoma detection rate and average withdrawal time.

Doing your part
A quality colonoscopy begins with a quality bowel preparation, and even the best doctor cannot do that for you. Did you know that you also receive a score for your part of the colonoscopy? Your doctor rates the effectiveness of your colon prep and gives you a score. If you have followed all preparation guidelines and have completely cleansed your colon, you have given your doctor every advantage to find and remove any precancerous polyps. An inadequate preparation could cause your doctor to miss a potentially dangerous lesion. Remember, if you are of average risk, a clear colonoscopy means that you do not have to repeat the procedure again for 10 years. Take the utmost care in your bowel cleanse and follow all instructions to the last detail.

10 Important Questions to Help you Get a Quality Colonoscopy
Answering these questions should help you make a decision about which specialist is the most qualified to perform your colonoscopy:

  1. Have you had formal training in endoscopy in a Gastroenterology fellowship or surgical residency?  If so, did you perform at least 140 colonoscopies during your training?
  2. Do you perform more than 100 colonoscopies annually?
  3. When performing a colonoscopy, is your rate of cecal (total colon) intubation greater than 90 percent?
  4. For colonoscopy, do you monitor adenoma detection rate, and is your adenoma detection rate at least 25 percent for men and 15 percent for women?
  5. If you do not monitor adenoma detection rate, do you measure and track withdrawal time of the endoscope from the cecum, and if so, does it average greater than 6 minutes?
  6. Do you monitor and track the effectiveness of colonoscopy preparation?
  7. Do you assess patients for pre-procedure anesthesia risk using the American Society of Anesthesia (ASA) classification?
  8. Do you provide written discharge instructions, and do you have 24-hour emergency assistance for questions or problems after a procedure?
  9. Do you track and report immediate complications if they occur during or after a procedure?
  10. Does your endoscopic facility have dedicated reprocessing (disinfection) personnel and equipment? Are the reprocessing personnel assessed on a regular basis for ongoing competency?