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. Author manuscript; available in PMC: 2010 Mar 1.
Published in final edited form as: Gastrointest Endosc. 2009 Mar;69(3 Pt 2):645–653. doi: 10.1016/j.gie.2008.08.034

Assessment of Quality of Colonoscopy Reports: Results from a multi-center consortium

David A Lieberman 1, Douglas O Faigel 2, Judy Logan 3, Nora Mattek 4, Jennifer Holub 5, Glenn Eisen 6, Cynthia Morris 7, Robert Smith 8, Marion Nadel 9
PMCID: PMC2749320  NIHMSID: NIHMS100771  PMID: 19251005

Abstract

Background

In order to improve colonoscopy quality, reports must include key quality indicators which can be monitored.

Objective

To determine the quality of colonoscopy reports in diverse practice settings.

Setting

The consortium of the Clinical Outcomes Research Initiative (CORI), which includes 73 gastroenterology practice sites in the United States which use a structured computerized endoscopy report generator, which includes fields for specific quality indicators.

Design

Prospective data collection from 2004 to 2006.

Main Outcomes Measurements

Reports were queried to determine if specific quality indicators were recorded. Specific endpoints, including quality of bowel prep, cecal intubation rate and detection of polyp(s) >9mm in screening exams were compared in 53 practices with more than 100 colonoscopy procedures per year.

Results

Of the 438,521 reports received during the study period, 13.9% did not include bowel prep quality and 10.1% did not include co-morbidity classification. The overall cecal intubation rate was 96.3%, but cecal landmarks were not recorded in 14% of reports. Missing polyp descriptors included polyp size (4.9%) and morphology (14.7%). Report of interventions for adverse events during the procedure varied from 0 to 6.5%. Among average-risk patients receiving screening exams, the detection rate of polyps >9mm, adjusted for age, gender and race, was between 4 and 10% in 81% of practices.

Limitation

Bias toward high rates of reporting because of standard use of a computerized report generator.

Conclusion

There is significant variation in quality of colonoscopy reports across diverse practices, despite the use of a computerized report generator. Measurement of quality indicators in clinical practice can identify areas for quality improvement.

Introduction

Colonoscopy is used for primary colorectal cancer (CRC) screening, surveillance of patients with prior colon neoplasia or cancer and for diagnosis in patients with lower gastrointestinal (GI) tract symptoms. Colonoscopy is also used to evaluate patients with positive CRC screening with fecal occult blood test (FOBT), sigmoidoscopy, fecal DNA or imaging. There is evidence that utilization of colonoscopy has increased dramatically in the past few years, largely due to increased rates of CRC screening (1–3). The effectiveness and safety of colonoscopy depend on the quality of examination, and a growing body of evidence suggests that the quality of colonoscopy in clinical practice varies (4,5).

In 2002, the Multi-Society Task Force on colorectal cancer (MSTF-CRC) published specific recommendations to improve the quality and effectiveness of colonoscopy (4). This important contribution highlighted key indicators for continuous quality improvement (CQI), and suggested targets for specific indicators. In 2006, Rex et al (5) added background data with identification of levels of evidence that supported key quality indicators and proposed targets in the earlier document. In 2007, the Quality Assurance Task Force of the National Colorectal Cancer Roundtable developed a reporting and data system for colonoscopy (CO-RADS) to assist endoscopists in monitoring quality indicators in their practice (6).

Structured, computerized endoscopic reporting systems provide an ideal tool for monitoring quality indicators. The Clinical Outcomes Research Initiative (CORI) developed a computerized endoscopic reporting system to study outcomes of endoscopy in the United States. Data are transmitted electronically to a central data repository for analysis. The CORI consortium includes 73 diverse practice sites in 24 states, and receives about 350,000 endoscopic reports annually.

Quality of colonoscopy cannot be measured or improved if reports do not include key quality indicators. Therefore, the aims of the current study are to determine 1) if the colonoscopy reports include key quality indicators and 2) to measure actual performance relative to specific targets for bowel prep quality, cecal intubation and detection of polyps >9mm on screening exams within each practice in the CORI consortium. A secondary aim is to assess the degree of variation in these measured quality indicators among practices that use the same computerized report generator.

Methods

Clinical Outcomes Research Initiative (CORI)

The CORI consortium includes 73 gastroenterology practice sites in 24 states. Practice sites include private practice (79% of colonoscopy reports), academic sites (10%) and VA sites (11%). Practice sites were selected to represent a complete spectrum of GI practices and include both urban and rural sites in each region of the country. Participating physicians use a structured, computerized endoscopic report generator to produce their endoscopic reports. The data file from that report is transmitted electronically to a central data repository (National Endoscopic Database: CORI-NED). All colonoscopy reports received between January 1, 2004 and December 31, 2006 were included in this analysis. The study period was selected to represent a time period of greater than one year after the publication of the MSTF-CRC paper (4) on colonoscopy quality indicators and one year after the publication of the 2003 screening and surveillance guideline (7). We excluded reports in patients less than 20 years old.

Quality Indicators

We queried the database to identify specific quality indicators to the extent possible (Table 1). Data were compiled and analyzed for the entire consortium (CORI-NED), and analyzed for individual practices with more than 100 colonoscopies per year during the study period (n = 53) to measure practice variation. Practices with fewer than 100 colonoscopies per year were not included in the practice site analysis. Unplanned intervention(s) for adverse events included only those interventions which were reported at the time of colonoscopy.

Table 1.

Colonoscopy Quality Indicators*

Bowel Prep quality
 Field Completed (yes/no)
 Prep quality (if reported): Proportion with prep described as excellent, good or fair-adequate
American Society of Anesthesiology (ASA) Classification of Physicial Status (proxy for co-morbidity)
 Field Completed (yes/no)
 Rates of each classification in outpatient setting
Extent of exam
 Cecal intubation rate (when reaching cecum was intended)
 Documentation of cecal landmarks
Total Procedure time
 Time recorded (yes/no)
 Total procedure time
Procedure Indication: Polyp Surveillance
 Documented date and findings of prior exam (yes/no)
Polyp Descriptors

  • Polyp Size recorded (yes/no)

  • Polyp morphology recorded (yes/no)

  • Polyp retrieval and submission to pathology recorded (yes/no)

Unplanned events and interventions
 Rate of reported intervention(s) for immediate adverse event
In first time screening exams; rates of polyp >9mm**
 Average-risk screening
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*

adapted from CO-RADS (6)

**

polyp > 9mm is used as a surrogate of advanced neoplasia; adjusted for age, gender and race.

Data were collected prospectively in the CORI consortium. We used the proportion of patients with polyp(s) > 9mm or suspected malignant tumor as a surrogate endpoint for advanced neoplasia since we did not have pathology data from all sites. We analyzed data from more than 13,609 subjects undergoing colon screening from 22 sites which provide pathology to determine if the prevalence of the surrogate was representative of actual proportion of patients with histologically proven advanced neoplasia. In this sub-analysis, 7.0% subjects had histologically advanced neoplasia, including polyps of all sizes. If we used the presence of one of more polyps greater than 9mm as a surrogate, the “surrogate” rate was 6.8%. Based on this close association, we have used the surrogate in the current analysis.

To measure the prevalence of polyp(s)>9mm among screening patients we identified patients for whom the indication for colonoscopy was average-risk screening. We also identified cohorts with a family history of CRC and positive fecal occult blood test (FOBT) for comparison. Patients were excluded from this analysis if there were any other indications listed for colonoscopy, such as pain or change in bowel habits. If a patient had more than one screening exam during the time period, only the first was considered. We employed multivariate regression analysis to statistically construct standardized polyp(s) >9mm detection rates among average risk patients adjusted for the population age (dichotomized as <65 years vs >=65 years), gender and race (white vs non-white) distribution. All analyses were performed using SAS software version 9.1 (SAS Institute, Inc., Cary, NC).

Results

From 2004 to 2006, CORI received 438,521 colonoscopy reports. Patient demographics and procedure indications are described in Table 2.

Table 2.

Patient Demographics (n = 438,521)

N %
Age (years)
20–29 7183 1.6%
30–39 15795 3.6%
40–49 46615 10.6%
50–59 150,642 34.4%
60–69 115,025 26.2%
70–79 77409 17.7%
>79 25852 5.9%
Gender
Female 215016 49%
Male* 223505 51%
Race/Ethnicity**
White, non-Hispanic 374019 85.6%
Black non-Hispanic 25238 5.8%
Asian/PI 6674 1.5%
Native American 2949 0.7%
Multi-racial, non-Hispanic 714 0.2%
Hispanic 27586 6.3%
Site Type
Community/HMO 344,989 79%
VA/Military 49,691 11%
Academic 43,841 10%
Procedure Indications***
Screening
Average-risk 129970 29.6%
Family history of CRC 47091 10.7%
Family history of polyps 11830 2.7%
Positive FOBT 22,974 5.2%
Surveillance of:
Polyps 72163 16.5%
CRC 11104 2.5%
Ulcerative colitis 5360 1.2%
Crohns 3081 0.7%
Evaluation of Symptoms
Hematochezia 67105 15.3%
Anemia 22627 5.2%
Weight loss 5839 1.3%
IBS cluster**** 91978 21.0%
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*

includes VA patients

**

Reports with missing or unknown race are excluded

***

Patients may have more than one indication

****

defined as one or more: diarrhea, constipation, abdominal pain/bloating or change in bowel habits

Pre-Procedure Indicators

ASA Classification field was not completed in 10.1% of reports. In 10 of 53 sites, completion rates were less than 90% (Fig 1a). When completed, 7.0% of exams were performed in high-risk individuals with ASA class 3 or higher.

Figure 1. Pre-Procedure Indicators based on patient history.

Figure 1

Figure 1

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Figure 1a: Percentage of reports with ASA Classification field documented, for each practice site

Figure 1b: Percentage of reports with information on prior colon exam in patients receiving polyp surveillance, for each practice site.

The quality of the bowel prep was not recorded in 13.9% of reports. In 14 of 53 practices, more than 20% of exams did not have a recorded bowel prep quality (Fig 2a). When reported, the quality was described as excellent, good or fair in 94.3% (range 84–100%) excluding one outlier site (Fig 2b).

Figure 2. Bowel Prep indicators.

Figure 2

Figure 2

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Figure 2a: Percentage of reports with adequacy of bowel preparation documented, for each practice site

Figure 2b: Percentage of reports with bowel preparation quality described as adequate*, for each practice site

* Includes excellent, good or fair bowel prep quality.

Table 2 presents the overall patient demographics and procedure indications for all colonoscopy reports received. Polyp surveillance accounts for 16.5% of exams. In order to determine if surveillance was performed at an appropriate interval, the report would need to include information from the last colonoscopy. These data would include the date and endoscopic and histologic findings of the previous colonoscopy. This information was absent in 66.1% of patients undergoing polyp surveillance (Fig 1b). Therefore, in most cases, the colonoscopy report lacked sufficient information to determine if the surveillance interval was consistent with published guidelines.

Procedure-related indicators

All reports included information about cecal intubation because it is a required field. The cecum or ileum was reached in 94.8% of exams (range 88–99%). In some cases, cecal intubation was not intended such as exams for colitis or obstruction. When cecal intubation was intended, the cecum was reached in 96.3% of exams. Four of 53 sites reported rates less than 90% (Fig 3). Cecal landmarks (appendiceal orifice and/or ileocecal valve) were reported in 85.9% of the reports when the cecum was reached. The CORI database has a field for total procedure time, and does not have separate fields for insertion and withdrawal times in the software version used for this analysis. Procedure time was recorded in 65.2% of exams, with wide variation in reporting among sites (Fig 4). When recorded, only 1.6% of exams were less than 10 minutes, and nearly 38% of exams were 10–20 minutes in duration. All other exams exceeded 20 minutes.

Figure 3.

Figure 3

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Rate of cecal intubation when intended, for each practice site

Figure 4.

Figure 4

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Percentage of reports with procedure duration documented for each practice site

Procedure outcomes

Polyps (n = 258,601 polyps) were found in 159,449 procedures (36.3%). Overall, polyp size was not recorded in 4.9% of reported polyps. However, in 15% of practices (8/53), size was not reported in more than 10% of polyps (Fig 5a). Polyp morphology (pedunculated, sessile, flat) was not reported in 14.7% of reported polyps. Whether or not the polyp was retrieved for pathology was not documented in 4.5%. Variation among practices is shown in Figures 5b and 5c.

Figure 5. Polyp Indicators.

Figure 5

Figure 5

Figure 5

Figure 5

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Figure 5a. Percentage of polyps with polyp size documented, for each practice site

Figure 5b. Percentage of polyps with polyp morphology documented, for each practice site

Figure 5c. Percentage of polyps for which polyp retrieval documented, for each practice site

Figure 5d. Percentage of average-risk subjects with one or more polyps >9mm documented, adjusted for age, gender and race, for each practice site.

We measured the proportion of exams in unique patients with one or more polyps >9mm in three different screening cohorts. If a patient had more than one screening exam during the time period, only the first was considered. Patients were excluded from this analysis if they had any other indication for colonoscopy. In the average-risk cohort, (n = 114,069), 6.3% had polyp(s) >9mm. Among patients with a family history of CRC (n = 33,428), 5.7% had polyp(s) >9mm. Patients with a positive fecal occult blood test were included for comparison if they had no other GI symptoms (n = 15,811). The rate of polyp(s) greater than 9mm was 12.1% in this group. Figure 5d displays the standardized polyp(s) >9mm detection rates among average risk exams in each practice, after adjusting for the population age, gender and race distribution. Based on published literature, the expected range for prevalence of polyp(s) >9mm in average risk individuals over 50 years would be 4–10%. We find that 10 of 53 practices (19.2%) are either above or below this range, and that 9 of the 10 of outlier practices performed fewer than 8,000 procedures during the study period.

We determined the proportion of reports which included one or more unplanned interventions for an adverse event. The range of reporting of interventions was 0 to 6.5%. Seventy-four percent of sites reported interventions in ≤1.0% of procedures (Fig 6).

Figure 6.

Figure 6

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Percentage of reports documenting intervention(s) for immediate adverse event(s), for each practice site.

Discussion

The increasing utilization of screening and diagnostic colonoscopy has focused attention on the quality of the performance of the procedure (4–6). Over the past few years, new data have emerged which highlight possible shortfalls in colonoscopy performance. Recent studies (8–12) have reported interval cancers (0.3–0.9%) within 2 to 3 years of colonoscopy in adenoma-bearing patients which could be due to missed lesions, incomplete removal (13) or new, fast growing lesions (14). The first two factors may be related to the quality of colonoscopy and polypectomy. The problem of missed lesions was highlighted by CT colonography studies which compared CT imaging with optical colonoscopy using a method of segmental unblinding. Optical colonoscopy missed 2–12% of polyps greater than 10mm (15–17). Other studies have highlighted variation in the rates of adenoma detection among physicians (18), and noted a relationship between endoscope withdrawal time and rate of adenomas in first-time screening exams. These studies suggest that the potential benefits of colonoscopy depend on the quality of the exam.

The Quality Assurance Task Group of the National Colorectal Cancer Roundtable published a standardized reporting system (CO-RADS) to enable every endoscopist to monitor quality indicators in their practice (6). Practices can utilize these data to initiate quality improvement measures. This effort was modeled after successful efforts in radiology to standardize reporting systems for mammography and CT colonography (19,20). The current study is the largest attempt to measure colonoscopy quality across different practice settings in the United States. We selected a time period for study one to two years after publication of quality indicators by the Multi-Society Task Force (4) so that it would be likely that endoscopists would be aware of the indicators. The CORI software captures most of the indicators proposed in CO-RADS (6). New versions of CORI will include all of the key indicators. An underlying principle of quality improvement is that quality indicators must be recorded, in order to monitor and improve quality. Therefore, our study focused on both the quality of the colonoscopy report, and a few specific quality indicators.

Our results reveal that even with a structured report generator, some key quality fields were often incomplete. Several of these fields are important in determining the quality of the exam, including bowel prep quality (absent in 13.9%) and specific mention of cecal landmarks (absent in 14.1%). The current guidelines suggest that endoscopists produce photographic documentation of cecal landmarks to establish confirmation that intubation was achieved (6). Without this information in the report, a careful reviewer could not confirm whether the exam was complete and adequate. The absence of these data could result in unnecessary repeat examinations.

A key element of exam quality is whether the procedure is indicated. There is evidence from physician surveys that colonoscopy for polyp surveillance is over-utilized, which may expose patients to unnecessary cost and risk (21,22). To determine if this is a problem in clinical practice based on the colonoscopy report, the report would need to include documentation of the prior colonoscopy exam and its findings. In most cases, we found this documentation was lacking, and therefore, it was not possible to determine if the interval was appropriate. Further study will be needed to monitor the appropriate use of colonoscopy for polyp surveillance.

Finally, the omission of key polyp descriptors (size, morphology) may impact decisions for surveillance colonoscopy. Current guidelines call for a three year surveillance interval if adenomas are ≥ 10mm. If size is omitted (5% of exams), it would be difficult to determine the appropriate timing for surveillance.

We note other deficiencies in reporting which are important, but do not directly impact exam quality. The ASA classification was absent in 10.1% of reports. While this indicator does not reflect exam quality, it is an important surrogate of co-morbidity (23). Prior work has shown an association between higher class and adverse events (24,25). Procedure duration was not recorded in 35% of exams. Our study period pre-dated a recent study showing a relationship between withdrawal time and adenoma detection rate (18). In addition, it is possible that other systems, such as nursing chart notes, may document the procedure duration. Physicians may not record the time if it is being noted elsewhere. When time was recorded, only a small proportion of exams were less than 10 minutes in duration (1.6%).

We report on performance of three key quality indicators: cecal intubation rate, polyp detection rate and unplanned interventions for adverse events. In most cases, endoscopists reached the cecum when this was intended (96.3%), although as noted above, reporting or photodocumentation of cecal landmarks were sometimes absent. It should be noted that most CORI physicians are board-certified gastroenterologists. In the United States, more than 18% of colonoscopy exams are performed by non-GI trained physicians (26,27), and it is possible that cecal intubation rates may not be as high in other clinical settings.

A primary goal of screening and surveillance is the detection and removal of neoplastic polyps. We note considerable variation in the rates of finding one or more polyps > 9mm in screening examinations. In clinical studies (15, 28–31), 4–10% of average-risk subjects have advanced neoplasia, defined by polyp size (≥10mm) or histology (villous or high-grade dysplasia). Our study uses size > 9mm as a surrogate for advanced neoplasia. In our analysis of pathology from selected CORI sites, this rate is similar to the overall rate of advanced neoplasia. After adjusting for age, gender and race, we find that 81% of practices had detection rates of 4–10% for average-risk individuals (Fig 5d). Outliers (both high and low) tended to be low-volume sites. Higher volume sites may include more endoscopists so that the effect of an individual endoscopist with an unusually high or low adenoma detection rate will be diluted. Future analyses will include individual provider quality data. Variation in detection rates may also be due to variable patient demographics in the practice although our data were adjusted for patient demographics. Finally, such variation may be a reflection of exam quality.

The harms of colonoscopy in clinical practice are uncertain (32–37). Certain patient populations (elderly, ASA class 3 or higher) may have a higher risk of adverse events than other patients (24,25). Recent reports from various practice sites have suggested that rates may be higher than those observed in clinical trials performed by expert colonoscopists (35–37). We note wide practice variation in the rate of reporting adverse events (0.2–7.4%) which may reflect different reporting thresholds. For example, some practitioners may note every episode of oxygen desaturation to less than 90%. Others, may not record such events if they are transient. Therefore, we focused on unplanned interventions for adverse events, assuming that if the event was significant enough to require an intervention, it would be clinically important, and likely to be reported. CORI provides structured fields to indicate the type of event and the nature of any unplanned intervention. We note variation (0 to 6.5%) in reporting unplanned interventions, with 26% of sites reporting interventions in more than 1% of procedures. These differences among sites may be due to true variation in adverse event rates or may reflect reporting threshold practice. If the primary reason for variation is the threshold for reporting events, our data suggest the need for a more standard method of classification and reporting of significant events and interventions so that meaningful quality improvement programs can be initiated.

Our study is biased toward finding high rates of completion of quality indicators because each physician used a structured report generator which provided a field for completion of the specific indicator. It is possible that physicians using unstructured reports, with dictation, may be less likely to record all of the indicators. Nevertheless, even using a structured report, areas for quality improvement are evident in some practices. CORI may be subject to self-selection bias, by including physicians who are comfortable sharing data about their practice, and may not reflect practice elsewhere.

In summary, this analysis provides a snapshot of quality of colonoscopy reporting in the United States. Quality improvement depends on monitoring quality indicators in daily practice. We observe considerable variation among 53 diverse practices. This study demonstrates that quality indicators of colonoscopy can be measured in the flow of clinical practice. Such measurement is facilitated by using a computerized report generator. Routine measurement of quality indicators could lead to a process of quality improvement in the practice of colonoscopy.

Acknowledgments

Grant Support: This project was supported with funding from NIDDK UO1 DK57132, the American Cancer Society and the Centers for Disease Control and Prevention. In addition, the practice network (Clinical Outcomes Research Initiative) has received support from the following entities to support the infrastructure of the practice-based network: AstraZeneca, Bard International, Pentax USA, ProVation, Endosoft, GIVEN Imaging, and Ethicon. The commercial entities had no involvement in this research.

Acronyms

CRC

Colorectal cancer

GI

Gastrointestinal

FOBT

Fecal occult blood test

MSTF-CRC

Multi-Society Task Force on Colorectal Cancer

CQI

Continuous Quality Improvement

CO-RADS

Colonoscopy reporting and data system

CORI

Clinical Outcomes Research Initiative

CORI-NED

CORI National Endoscopic Database

ASA

American Society of Anesthesiology classification

CT Colonography

Computerized Tomographic Colonography

Footnotes

Dr. Lieberman is the executive director of the Clinical Outcomes Research Initiative (CORI), a non-profit organization that receives funding from federal and industry sources. The CORI database is used in this study. This relationship has been reviewed and managed by the OHSU Conflict of Interest in Research Committee and the VA Conflict of Interest in Research committee.

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Contributor Information

David A. Lieberman, Oregon Health and Science University

Douglas O. Faigel, Oregon Health and Science University

Judy Logan, Oregon Health and Science University.

Nora Mattek, Oregon Health and Science University.

Jennifer Holub, Oregon Health and Science University.

Glenn Eisen, Oregon Health and Science University.

Cynthia Morris, Oregon Health and Science University.

Robert Smith, American Cancer Society.

Marion Nadel, Centers for Disease Control and Prevention.

References

  • 1.Cram P, Fendrick AM, Inadomi J, Cowen ME, Carpenter D, Vijan S. The impact of a celebrity promotional campaign on the use of colon cancer screening: the Katie Couric effect. Arch Intern Med. 2003;163(13):1601–5. doi: 10.1001/archinte.163.13.1601. [DOI] [PubMed] [Google Scholar]
  • 2.Harewood GC, Lieberman DA. Colonoscopy practice patterns since introduction of Medicare coverage for average-risk screening. Clin Gastro Hep. 2004;2:72–77. doi: 10.1016/s1542-3565(03)00294-5. [DOI] [PubMed] [Google Scholar]
  • 3.Lieberman DA, Holub J, Eisen G, Kraemer D, Morris CD. Utilization of colonoscopy in the United States: results from a national consortium. Gastrointest Endosc. 2005;62:875–83. doi: 10.1016/j.gie.2005.06.037. [DOI] [PubMed] [Google Scholar]
  • 4.Rex DK, Bond JH, Winawer S, Levin TR, Burt RW, Johnson DA, Kirk LM, Litlin S, Lieberman DA, Waye JD, Church J, Marshal JB, Riddell RH. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: Recommendations of the U.S. Multi-Society task force on colorectal cancer. Am J Gastroenterology. 2002;97:1296–1308. doi: 10.1111/j.1572-0241.2002.05812.x. [DOI] [PubMed] [Google Scholar]
  • 5.Rex DK, Petrini JL, Baron TH, Chak A, Cohen J, Deal SE, Hoffman B, Jacobson BC, Mergener K, Petersen BT, Safdi MA, Faigel DO, Pike IM. Quality indicators for colonoscopy. Am J Gastroenterology. 2006;101:873–885. doi: 10.1111/j.1572-0241.2006.00673.x. [DOI] [PubMed] [Google Scholar]; Gastrointest Endosc. 2006;63:S16–S28. doi: 10.1016/j.gie.2006.02.021. [DOI] [PubMed] [Google Scholar]
  • 6.Lieberman D, Nadel M, Smith R, Atkin W, Duggirala S, Fletcher R, Glick S, Johnson CD, Levin TR, Pope J, Potter M, Ransohoff D, Rex D, Schoen R, Schroy P, Winawer S. Standardized colonoscopy reporting and data system (CO-RADS): Report of the Quality Assurance Task Group of the National Colorectal Cancer Roundtable. Gastrointest Endosc. 2007;65:757–66. doi: 10.1016/j.gie.2006.12.055. [DOI] [PubMed] [Google Scholar]
  • 7.Winawer S, Fletcher R, Rex D, Bond J, Burt R, Ferrucci J, Ganiats T, Levin T, Woolf S, Johnson D, Kirk L, Litin S, Simmang C. Colorectal cancer screening and surveillance: clinical guidelines and rationale – Update based on new evidence. Gastroenterology. 2003;124:544–60. doi: 10.1053/gast.2003.50044. [DOI] [PubMed] [Google Scholar]
  • 8.Schatzkin A, Lanza E, Corle D, Lance P, Iber F, Caan B, Shike M, Weissfeld J, Burt R, Cooper MR, Kikendall JW, Cahill J the Polyp Prevention Trial Study Group. Lack of effect of a low-fat, high-fiber diet on the recurrence of colorectal adenomas. N Engl J Med. 2000;342:1149–55. doi: 10.1056/NEJM200004203421601. [DOI] [PubMed] [Google Scholar]
  • 9.Alberts DS, Martinez ME, Roe DJ, Guillen-Rodriguez JM, Marshal JR, van Leeuwen JB, Reid ME, Ritenbaugh C, Vargas PA, Bhattacharyya AB, Earnest DL, Sampliner RE the Phoenix Colon Cancer Prevention Physicians Network. Lack of effect of a high-fiber cereal supplement on the recurrence of colorectal adenomas. N Engl J Med. 2000;342:1156–62. doi: 10.1056/NEJM200004203421602. [DOI] [PubMed] [Google Scholar]
  • 10.Robertson DJ, Greenberg ER, Beach M, Sandler RS, Ahnen D, HAile RW, Burke CA, Snover DC, Bresalier RS, McKeown-Eyssen G, Mandel JS, Bond JH, Van Stolk RU, Summer RW, Rothstein R, Church TR, Cole BF, Byers T, Mott L, Baron JA. Colorectal cancer in patients under close colonoscopic surveillance. Gastroenterology. 2005;129:34–41. doi: 10.1053/j.gastro.2005.05.012. [DOI] [PubMed] [Google Scholar]
  • 11.Bertagnolli MM, Eagle CJ, Zauber AG, Redston M, Solomon SD, Kim K, Tang J, Rosenstein RB, Wittes J, Corle D, Hess TM, Woloj GM, Boisserie F, Anderson WF, Viner JL, Bagheri D, Burn J, Chung DC, Dewar T, Foley TR, Hoffman N, Macrae F, Pruitt RE, Saltzman JR, Salzberg, Sylwestrowicz T, Gordon GB, Hawk ETMD for the APC Study Investigators. Celecoxib for the Prevention of Sporadic Colorectal Adenomas. N Engl J Med. 2006;355:873–84. doi: 10.1056/NEJMoa061355. [DOI] [PubMed] [Google Scholar]
  • 12.Arber N, Eagle CJ, Spicak J, Rácz I, Dite P, Hajer J, Zavoral M, Lechuga MJ, Gerletti P, Tang J, Rosenstein RB, Macdonald K, Bhadra P, Fowler R, Wittes J, Zauber AG, Solomon SD, Levin B for the PreSAP Trial Investigators. Celecoxib for the Prevention of Colorectal Adenomatous Polyps. N Engl J Med. 2006;355:885–95. doi: 10.1056/NEJMoa061652. [DOI] [PubMed] [Google Scholar]
  • 13.Pabby A, Schoen RE, Weissfeld JL, Burt R, Kikendall JW, Lance P, Shike M, Lanza E, Schatzkin A. Analysis of colorectal cancer occurrence during surveillance colonoscopy in the dietary polyp prevention trial. Gastrointest Endosc. 2005;61:385–91. doi: 10.1016/s0016-5107(04)02765-8. [DOI] [PubMed] [Google Scholar]
  • 14.Sawney MS, Farrar WD, Gudiseva S, Nelson DB, Lederle FA, Rector TS, Bond JH. Microsatellite instability in interval colon cancers. Gastroenterology. 2006;131:1700–5. doi: 10.1053/j.gastro.2006.10.022. [DOI] [PubMed] [Google Scholar]
  • 15.Pickhardt PJ, Choi R, Hwang I, Butler JA, Puckett ML, Hildebrandt HA, Wong RK, Nugent PA, Mysiliwiec PA, Schindler WR. Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. N Engl J Med. 2003;349:2191–2200. doi: 10.1056/NEJMoa031618. [DOI] [PubMed] [Google Scholar]
  • 16.Cotton PB, Durkalski VL, Pineau BC, Palesch YY, Mauldin PD, Hoffman B, Vining DJ, Small WC, Affronti J, Rex D, Kopecky KK, Ackerman S, Burdick JS, Brewington C, Turner MA, Zfass A, Wright AR, Iyer RB, Lynch P, Sivak MV, Butler H. Computed tomographic colonography (Virtual Colonoscopy): A multicenter comparison with standard colonoscopy for detection of colorectal neoplasms. JAMA. 2004;291:1713–9. doi: 10.1001/jama.291.14.1713. [DOI] [PubMed] [Google Scholar]
  • 17.Rockey DC, Paulson E, Niedzwiecki D, Davis W, Bosworth HB, Sander L, Yee J, Henderson J, Hatten P, Burdick S, Sanyal A, Rubin DT, Sterline M, Akerkar G, Bhutani MS, Binmoeller K, Garvie J, Bini EJ, McQuaid K, Foster WL, Thompson WM, Dachman A, Halvorsen R. Analysis of air contrast barium enema, computed tomographic colonography and colonoscopy: prospective comparison. Lancet. 2005;365:305–11. doi: 10.1016/S0140-6736(05)17784-8. [DOI] [PubMed] [Google Scholar]
  • 18.Barclay RL, Vicari JJ, Doughty AS, Johanson JF, Greenlaw RL. Adenoma detection rates and colonoscopic withdrawal times during screening colonoscopy. N Engl J Med. 2006;355:2533–41. doi: 10.1056/NEJMoa055498. [DOI] [PubMed] [Google Scholar]
  • 19.American College of Radiology. Bi-RADS Atlas: Breast Imaging and Reporting Data System. 4. Reston, Virginia: American College of Radiology; 2003. [Google Scholar]
  • 20.Zalis ME, Barish MA, Choi JR, Dachman AH, Fenlon HM, Ferrucci JT, Glick SN, Laghi A, Macari M, McFarland EG, Morrin MM, Pickhardt PJ, Soto J, Yee J. CT colonography reporting and data system: A consensus proposal. Radiology. 2005;236:3–9. doi: 10.1148/radiol.2361041926. [DOI] [PubMed] [Google Scholar]
  • 21.Mysliwiec PA, Brown ML, Klabunde CN, Ransohoff DF. Are physicians doing too much colonoscopy? A national survey of colorectal surveillance after polpectomy. Ann Intern Med. 2004;141:264–71. doi: 10.7326/0003-4819-141-4-200408170-00006. [DOI] [PubMed] [Google Scholar]
  • 22.Boolchand V, Olds G, Singh J, Singh P, Chak A, Cooper GS. Colorectal screening after polypectomy: A national survy study of primary care physicians. Ann Intern Med. 2006;145:654–9. doi: 10.7326/0003-4819-145-9-200611070-00007. [DOI] [PubMed] [Google Scholar]
  • 23.Prause G, Ratzenhofer-Comenda B, Pierer G, Smolle-Juttner F, Glanzer H, Smolle J. Can ASA grade or Goldman’s cardiac risk index predict peri-operative mortality? A study of 16,227 patients. Anesthesia. 1997;52(3):203–6. doi: 10.1111/j.1365-2044.1997.074-az0074.x. [DOI] [PubMed] [Google Scholar]
  • 24.Vargo JJ, Holub JL, Faigel DO, Lieberman DA, Eisen GM. Risk factors for cardiopulmonary events during propofol-mediated upper endoscopy and colonoscopy. Aliment Pharmacol Ther. 2006;24(6):955–63. doi: 10.1111/j.1365-2036.2006.03099.x. [DOI] [PubMed] [Google Scholar]
  • 25.Sharma VK, Nguyen CC, Crowell M, Lieberman DA, deGarmo P, Fleischer DE. A national study of caridopumonary complications following gastrointestinal endoscopy. Gastrointest Endosc. 2007;66:27–34. doi: 10.1016/j.gie.2006.12.040. [DOI] [PubMed] [Google Scholar]
  • 26.Seeff LC, Richards TB, Shapiro JA, Nadel MR, Manninen DL, Given LS, Dong FB, Winges LD, McKenna MT. How many endoscopies are performed for colorectal cancer screening? Results from CDC’s survey of endoscopic capacity. Gastroenterology. 2004;127:1670–7. doi: 10.1053/j.gastro.2004.09.051. [DOI] [PubMed] [Google Scholar]
  • 27.Brown ML, Klabunde CN, Mysliwiec P. Current capacity for endoscopic colorectal cancer screening in the United States: Data from the National Cancer Institute survey of colorectal canceer screening practices. Am J Med. 2003;115:129–33. doi: 10.1016/s0002-9343(03)00297-3. [DOI] [PubMed] [Google Scholar]
  • 28.Lieberman DA, Weiss DG, Bond JH, Ahnen DJ, Garewal H, Chejfec G VACSP Group # 380. Use of colonoscopy to screen asymtomatic adults for colorectal cancer. N Engl J Med. 2000;343:162–8. doi: 10.1056/NEJM200007203430301. [DOI] [PubMed] [Google Scholar]
  • 29.Imperiale TF, Wagner DR, Lin CY, Larkin GR, Rogge JD, Ransohoff DF. Risk of advanced proximal neoplasms in asymptomatic adults according to the distal colorectal findings. N Engl J Med. 2000;343:169–74. doi: 10.1056/NEJM200007203430302. [DOI] [PubMed] [Google Scholar]
  • 30.Schoenfeld P, Cash B, Flood A, Dobhan R, Eastone J, Coyle W, Kikendall JW, Kim HM, Weiss DG, Emory T, Schatzkin A, Lieberman D. Colonoscopic screening of average-risk women for colorectal neoplasia. N Engl J Med. 2005;352:2061–8. doi: 10.1056/NEJMoa042990. [DOI] [PubMed] [Google Scholar]
  • 31.Regula J, Rupinski M, Kraszewska E, Polkowski M, Pachlewski J, Orlowska J, Nowacki MP, Brtruk E. Colonoscopy in colorectal-cancer screening for detection of advanced neoplasia. N Engl J Med. 2006;355:1863–72. doi: 10.1056/NEJMoa054967. [DOI] [PubMed] [Google Scholar]
  • 32.Nelson DB, McQuaid KR, Bond JH, Lieberman DA, et al. Procedural success and complications of large-scale screening colonoscopy. Gastrointest Endosc. 2002;55:307–14. doi: 10.1067/mge.2002.121883. [DOI] [PubMed] [Google Scholar]
  • 33.Korman LY, Overholt BF, Box T, Winker CK. Perforation during colonoscoy in endoscopic ambulatory surgical centers. Gastrointest Endosc. 2003;58:554–7. doi: 10.1067/s0016-5107(03)01890-x. [DOI] [PubMed] [Google Scholar]
  • 34.Ko CW, Riffle S, Shapiro JA, Saunders MD, Lee SD, Tung BY, Kuver R, Larson AM, Kowdley KV, Kimmey MB. Incidence of minor complications and time lost from normal activities after screening or surveillance colonoscopy. Gastrointrointest Endosc. 2007;65:648–56. doi: 10.1016/j.gie.2006.06.020. [DOI] [PubMed] [Google Scholar]
  • 35.Levin TR, Zhao W, Conell C, Seeff LC, Manninen DL, Shapiro JA, Schulman J. Complications of colonoscopy in an integrated health care delivery system. Ann Intern Med. 2006;145:880–6. doi: 10.7326/0003-4819-145-12-200612190-00004. [DOI] [PubMed] [Google Scholar]
  • 36.Ko CW, Riffle S, Morris C, Michaels L, Holub J, Shapiro JA, Seeff L, Lieberman DA. Complications after screening and surveillance colonoscopy. Gastroenterology. 2007;132:A149. doi: 10.1016/j.cgh.2009.10.007. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Klabunde C, Warren J, Ransohoff DF, Brown ML. Complications of colonoscopy in the Medicare population. Gastroenterology. 2007;132:A149. [Google Scholar]

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