The Quality of Colonoscopy Services—Responsibilities of Referring
A Consensus Statement of the Quality Assurance Task Group, National Colorectal Cancer
Robert H. Fletcher, MD, MSc1,13, Marion R. Nadel, PhD2, John I. Allen, MD3,
Jason A. Dominitz, MD, MHS4, Douglas O. Faigel, MD5, David A. Johnson, MD6,
Dorothy S. Lane, MD7, David Lieberman, MD5, John B. Pope, MD8, Michael B. Potter, MD9,
Deborah P. Robin, RN, MSN10, Paul C. Schroy III MD, MPH11, and Robert A. Smith, PhD12
1Harvard Medical School and Harvard Pilgrim Health Care, Boston, MA, USA;2Division of Cancer Prevention and ControlCenters for Disease
Control and Prevention, Atlanta, GA, USA;3Minnesota Gastroenterology, Saint Paul, MN, USA;4VA Puget Sound Heath Care System, Seattle,
WA, USA;5Oregon Health and Sciences University, Portland, OR, USA;6Eastern Virginia Medical School, Norfolk, VA, USA;7Stony Brook
University School of Medicine, Stony Brook, NY, USA;8Louisiana State University of Medicine, Shrevepor, LA, USA;9University of California San
Francisco, San Francisco, CA, USA;10American Gastroenterological Association, Bethesda, MD, USA;11Boston University School of Medicine,
Boston, MA, USA;12The American Cancer Society, Atlanta, GA, USA;13208 Boulder Bluff, Chapel Hill, NC, USA.
Primary care clinicians initiate and oversee colorectal
screening for their patients, but colonoscopy, a central
component of screening programs, is usually performed
by consultants. The accuracy and safety of colonoscopy
varies among endoscopists, even those with main-
stream training and certification. Therefore, it is a
primary care responsibility to choose the best available
colonoscopy services. A working group of the National
Colorectal Cancer Roundtable identified a set of indica-
tors that primary care clinicians can use to assess the
quality of colonoscopy services. Quality measures are of
actual performance, not training, specialty, or experi-
ence alone. The main elements of quality are a complete
report, technical competence, and a safe setting for the
procedure. We provide explicit criteria that primary care
physicians can use when choosing a colonoscopist.
Information on quality indicators will be increasingly
available with quality improvement efforts within the
colonoscopy community and growth in the use of
electronic medical records.
KEY WORDS: primary care clinicians; colorectal screening; endoscopist;
J Gen Intern Med 25(11):1230–4
© Society of General Internal Medicine 2010
guidelines1,2. Primary care clinicians initiate and oversee
colorectal cancer screening programs for their patients3.
However, colonoscopy, which is usually not performed by the
primary care clinicians themselves, is a central part of such
creening for colorectal cancer can prevent cancer inci-
dence and death and is recommended in clinical practice
programs—for screening, for diagnostic evaluation of positive
test results regardless of the initial screening test, and for
surveillance of patients at increased risk. Most colonoscopies
in the U.S. are performed by gastroenterologists and colorectal
surgeons, although other specialists also do this procedure4.
Thus, primary care clinicians and referral endoscopists share
responsibility for successful colorectal cancer screening.
The accuracy and safety of colonoscopy vary from clinician
to clinician, even among those with extensive experience5,6. In
a study of 12 full-time, board-certified gastroenterologists with
formal training, each of whom had performed at least 3,000
colonoscopies, adenoma detection rates ranged from 9.4% to
32.7%5. Withdrawal times ranged from 3.1 to 16.8 minutes in
patients in whom no polyps were found and endoscopists with
of cancer detection and perforation also vary among examiners7.
Given this variation in performance of colonoscopy, primary
care clinicians should be in a position to identify endoscopists
who meet high standards for quality. We have identified a set of
indicators that primary care clinicians can use to assess
quality of colonoscopy procedures. This work is part of a larger
effort to improve the quality of colonoscopy. In 2002, the U.S.
Multi-Society Task Force on Colorectal Cancer published
recommendations for indicators that should be measured by
colonoscopy practices as part of ongoing quality improvement8.
The Quality Assurance Task Group of the National Colorectal
Cancer Roundtable then developed a standardized reporting
system (CO-RADS) that specifies the elements that should be
included in colonoscopy reports and a standard method for
reporting them8. That documentation system should also serve
to improve communication with referring clinicians and
patients by providing reports that use standard terms and
include specific, evidence-based recommendations for follow-up.
These recommendations were developed by members of the
National Colorectal Cancer Roundtable, a coalition of nearly 60
Received February 09, 2010
Revised June 09, 2010
Accepted June 18, 2010
Published online August 12, 2010
public, private, and voluntary organizations who work togeth-
er, with support from the American Cancer Society and the
Centers for Disease Control and Prevention, to advance
colorectal cancer control through screening9. The Quality
Assurance Task Group, a working group of the Roundtable,
identified the importance of colonoscopy quality from the
primary care perspective at a meeting on November 5, 2007.
A panel of the Task Group, including three primary care
physicians (two family physicians and one general internist),
one preventive medicine specialist, six gastroenterologists, two
epidemiologists, and one nurse volunteered to prepare this
statement. This panel met by conference call and exchanged
views by email and telephone. Drafts of the statement were
revised and circulated until all members of the Panel approved
the recommendations. We based our recommendations on
existing research evidence and clinical practice guidelines.
While there is not strong, direct research evidence that these
recommendations change outcomes, all reflect the kinds of
performance measures—such as completeness of examina-
tion, adenoma detection rates, and safety—that matter to
patients and have been shown to be achievable. They also
reflect the information that clinicians need to have to make
evidence-based decisions about screening in individual
patients. For example, recommendations for surveillance
intervals depend on the number, size, and histology of
adenomas found on the preceding examination10.
RECOMMENDATIONS AND RATIONALE
Recommendations for the quality of colonoscopy services are
summarized in Table 1. The following describes the basis for
1. Elements of the Colonoscopy Report. We listed six basic
descriptors of what was done and what was found during the
colonoscopy based on earlier work by Task Group8. Each of
these descriptors is necessary to interpret the clinical
significance of findings and plans for follow-up.
Depth of insertion is related to the proportion of the colon
examined and thus the percent of adenomas and cancers
that could have been found. Confidence in a report that
the cecum was reached should be supported by a clear
description of anatomic landmarks (appendiceal orifice
and ileocecal valve) and photo documentation if it is
Quality of bowel preparation. Poor bowel preparation
results in missed lesions and follow-up examinations
scheduled sooner than the usually recommended inter-
val. The quality of bowel cleansing is a subjective
measure, but efforts are under way to increase repro-
ducibility and validity by establishing a common mea-
sure across endoscopists8and to anchor judgments in
an objective phenomenon such as “adequate to detect
polyps >5 mm”8.
Patient tolerance of the procedure is important infor-
mation for the clinician who coordinates the patient’s
care over time. For example, syncope during the bowel
preparation or procedure may signal cardiovascular risk
and require evaluation; bleeding from the procedure may
cause anemia, which should be diagnosed and treated.
Description of polyps. The number, size, location, mor-
phology (pedunculated, sessile, or flat) and histology of
adenomas has been related to recurrence rate and this, plus
completeness of polyp removal and biopsy results are the
basis for planning surveillance intervals10.
Pathology results for any biopsies. Recommendations for
follow-up and surveillance depend on information from both
the procedure itself and the pathology report. Despite
logistic challenges in obtaining pathology reports promptly,
referring clinicians should expect that the colonoscopist will
promptly communicate findings from the procedure itself,
the pathology, as well as recommendations both to them an
directly to the patient.
Recommendations for follow-up and/or surveillance
need to be explicit so that referring clinician, as well as
the patient, know what the endoscopist has recommended.
Recent, evidence-based guidelines, relating surveillance
interval to risk factors for subsequent advanced neoplasia,
are summarized in Table 211. If the recommended interval
differs from guidelines, the reasons should be made
Physicians in practice say they often choose shorter
surveillance intervals11than recommended in clinical prac-
tice guidelines. Because some risks and substantial costs
(measured both in financial and human terms) are at stake,
and the clinical benefit of short-interval colonoscopy surveil-
lance after initial polypectomy is low for most patients12, the
surveillance interval is an important decision for everyone
involved with the patient’s care
Family history information gathered at the time of
screening as well as some colonoscopy findings (such as
a malignancy or advanced adenomas at a young age) may
suggest that other family members are at increased risk
and should have earlier than usual screening with colono-
scopy. In the case of Lynch Syndrome, they are at
increased risk for other cancers as well. The endoscopy
report should include recommendations for colorectal
cancer screening in family members when appropriate.
The endoscopist and the primary care clinician have a
collective responsibility for encouraging patients to notify
family members if they are at increased risk, and for
recommending that these family members talk with their
own primary care clinician about colorectal cancer
2. Cecal Intubation Rate. Clinically-important adenomas and
cancers occur throughout the colon and will be missed to the
extent that the entire colon is not examined. Reports of
consecutive screening colonoscopies have established that
cecal intubation rates of over 90% are achievable13–18,
especially in patients without clinical reasons for incomplete
colonoscopies such as severe colitis, poor preparation, severe
diverticulosis, vital sign instability during the procedure17.
Several expert groups have set a quality target of 90% or higher
for cecal intubation rate7,19. Screening guidelines recommend
that if the cecum cannot be reached other imaging procedures
(computed tomographic colonography or double contrast
barium enema) should be used to complete the examination1.
We concluded that an average cecal intubation rate of at least
Fletcher et al.: The Quality of Colonoscopy Services
90% was achievable after excluding examinations that were
terminated for clinical reasons and those for which full
colonoscopy was not the original intent. Rates are lower in
some settings6,20,21,but there is evidence that rates can be
improved by quality improvement programs21. We recommend
that all endoscopists should aim to meet this target, regardless
of specialty, training, or experience.
3. Adenoma Detection Rate. The prevalence of adenomas at age
50 years is estimated to be 15% in women and 25% in men,
increases with age in both sexes7, and the majority of adenomas
are detected by colonoscopy22,23. It is not feasible to measure the
proportion of adenomas found for individual colonoscopists
against research standards, (a second colonoscopy and
computed tomographic colonography) so we chose adenoma
detection rates as a crude metric for the proportion of
adenomas found at colonoscopy. Adenoma detection rate
during screening colonoscopy has been shown to be inversely
related to the risk of interval cancers24. We confined this quality
measure to first colonoscopies because prior polypectomies can
change the prevalence of adenomas, making polyp prevalence
lower and detection rates more difficult to interpret.
4. Safe Setting. Colonoscopy can cause clinically-important
complications such as bleeding, perforation, and cardiovascular
events during bowel preparation or endoscopy. The procedure
can also spread infection if equipment is improperly cleaned and
disinfected. Although the great majority of colonoscopies occur
without incident, complication rate is an important aspect of
quality. However, we chose not to include complication rates in
the quality measures because events occur too infrequently to
allow stable estimates of rates for individual colonoscopists,
unless he or she has performed an unusually high volume of
Instead, the panel recommended that safety be assessed by a
surrogate measure, characteristics of the setting in which
procedures are done. Among these are adequate cleaning and
disinfection of equipment, well-maintained equipment, well-
trained endoscopist and staff, and the ability to react to
emergencies that might arise during the procedure25.
Table 1. Elements of Quality of Colonoscopy Services with Operational Definitions
Element of Quality Operational Definition
1, Does the colonoscopy report include:
a) Depth of insertion Was the cecum reached? If so, were landmarks described? If the cecum was not reached,
what were the reasons?
Was the bowel preparation adequate to detect polyps >5 mm?
What if any were the complications of the bowel preparation, sedation, and endoscopy?
For each polyp seen, what was the anatomic location, size (in mm), and morphology?
What was the method and completeness of removal?
What was the histologic description of removed tissue? (Pathology reports may be sent
after the rest of the colonoscopy report, when they become available from the
When should the next colonoscopy be scheduled? If the recommended interval differs from
national guidelines (see Table 2) the reasons should be stated. If family members are at
increased risk, based on the patient’s clinical presentation, how should they be screened?
there may be good reasons for not reaching the cecum in individual patients, average cecal
intubation rates above 90% (after taking into account examinations that have been aborted
because of poor bowel preparation, strictures, severe colitis, or when full colonoscopy was
not the original intent) have been achieved by many experienced endoscopists
Based on the known prevalence of adenomas by age and sex, endoscopists should detect
adenomas on initial screening examinations of adults 50 years old or older in at least
15% of women and 25% of men
Characteristics of a safe setting for colonoscopy are adequate cleaning and disinfection of
equipment, well-maintained equipment, well-trained endoscopist and staff, and the
ability to react to emergencies that might arise during the procedure. Some states and
professional societies have in place guidelines for safe settings and requirements for
accreditation but there is not a universally-accepted standard
b) Bowel preparation quality
c) Patient tolerance of the procedure
d) A description of polyps and whether they were removed
e) Pathology results for any biopsies
f) Clear recommendations for follow-up and/or surveillance
(whether or not the examination was complete)
2. Does the endoscopist have a high enough cecal
3. Does the endoscopist have a high enough adenoma
4. Is the colonoscopy performed in a safe setting?
Table 2. Recommended Surveillance Intervals After Polypectomy in Average Risk Patients (From 11)*
Colonoscopy Finding Interval to Next Colonoscopy (Years)
Normal of hyperplastic polyp†
1–2 tubular adenomas <1 cm with only low-grade dysplasia
3-10 adenomas or at any adenoma > = 1 cm or any adenoma with villous features or high-grade dysplasia
< 3 years‡
*These recommendations assume that the baseline colonoscopy was complete to the cecum, that bowel preparation was adequate, and that all polyps
identified were completely removed. The recommendations do not apply to patients who have a high risk of colorectal cancer because of previous
colorectal cancer, familial adenomatous polyposis, hereditary non-polyposis colon cancer (HNPCC < Lynch Syndrome), or inflammatory bowel disease.
† Since this table was published, there has been growing evidence that large or multiple hyperplastic polyps in the proximal colon may require earlier follow-up
‡ Consider the possibility of a familial syndrome
Fletcher et al.: The Quality of Colonoscopy Services
While some states and professional societies have guidelines
for safesettingsandrequirements for accreditation,primarycare
the colonoscopy setting is safe. At this time, there is no single,
overall mechanism for credentialing that applies to all specialties
that do colonoscopy and in all settings in which it is done.
We have identified a set of quality indicators that primary care
clinicians can use when deciding where to send their patients
for colonoscopy services. The need for a more rigorous
approach to choosing among endoscopists is highlighted by
reports of substantial variation in the quality of colonoscopy,
even among clinicians generally considered to have appropri-
ate training, experience, and credentials. The elements of
quality are based on the information needed to follow screen-
ing and surveillance guidelines. The targets we set have been
shown to be achievable in community settings.
We have recommended that primary care clinicians rely on
the actual performance of colonoscopy, not just the back-
ground and specialty of those who do the procedures. Specialty
societies have set standards for performance of colonoscopy
but they have not been universally adopted or enforced. In one
study of gastrointestinal endoscopy centers in the US, 60%
required no minimum number of procedures before granting
privileges, and two-thirds required no minimum number of
procedures per year26. Also, training, experience, and specialty
do not in themselves assure high quality colonoscopy5.
Is it feasible for primary care clinicians to implement these
recommendations? We would argue that primary care clini-
cians have always considered it a core responsibility to choose
the best available consultants, and now, at least for colono-
scopy, they are in a better position to meet that responsibility.
They are also better able to care for their patients if the report
of the procedure includes the information they need to explain
plans for colorectal cancer screening and surveillance to their
patients and judge the appropriateness of colonoscopy inter-
vals for themselves. In the absence of performance information
on individual endoscopists, it seems likely that consultants are
chosen based on other considerations, such as availability,
reputation, and congeniality. New models for how primary care
can be organized and financed, which are now being tested as
part of the patient-centered medical home movement27, might
foster, among many other improvements in care, ways to
identify consultants by performance.
Will individual endoscopists be able and willing to provide
information on their performance? Standardized reporting is
being promoted within the endoscopy community as part of a
larger set of quality improvement activities. We encourage
clinicians to refer patients to endoscopists who use a stan-
dardized reporting mechanism such as the CO-RADS lexicon8,
and to communicate with endoscopists that they value
receiving reports that follow this standard. If electronic medical
records become more widely implemented, information on
quality of colonoscopies may be easier to monitor and share.
There has been a lively debate in the literature about the
kind of training needed to perform high quality colonoscopy28.
The published literature is not yet robust enough to answer
this question with confidence. Whatever the answer, we
thought that the performance of each endoscopist should
stand on its own merits, as reflected in measurable quality
indicators such as the quality of the colonoscopy report and
cecal intubation and polyp detection rates. Choosing endosco-
py services according to actual performance is becoming
possible for the first time, as a result of efforts in the
colonoscopy community to set measurable quality standards
and the growing use of electronic medical records. With a
better understanding of quality standards for colonoscopy,
primary care clinicians can be better advocates for their
Acknowledgments: This work was supported by the Division of
Cancer Prevention and Control at the Centers for Disease Control
and Prevention, the American Cancer Society and the VA Puget
Sound Health Care System, Department of Veterans Affairs. Dr.
Dominitz was supported by an American Society for Gastrointestinal
Endoscopy Career Development Award.
The views expressed in this report are those of the authors and do
not necessarily represent the official position of the Centers for
Disease Control and Prevention or the Department of Veterans
Conflict of Interest: None of the authors has a financial tie to
entities that would stand to gain financially from implementation of
the recommendations in this statement.
Corresponding Author: Robert H. Fletcher, MD, MSc; 208 Boulder
Bluff, Chapel Hill, NC 27516, USA (e-mail: Robert_Fletcher@hms.
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