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Bowel Preparation: Is Fair Good Enough? Peter S. Liang, MD, MPH1 and Jason A. Dominitz, MD, MHS1,2
Abstract: The effectiveness of colonoscopy in reducing colorectal cancer incidence and mortality has been shown to be associated with an endoscopist’s adenoma detection rate, although the ability to detect adenomas depends, in part, on the quality of bowel preparation. Many endoscopists routinely recommend shorter examination intervals for colonoscopies with a fair or intermediate-quality bowel preparation, assuming that the preparation is insufﬁcient for the purpose of colorectal cancer screening. In this issue, Clark et al. performed a systematic review and meta-analysis to assess the adequacy of a fair-quality bowel preparation, ﬁnding no difference in the adenoma detection rate of colonoscopies with an intermediate-quality bowel preparation relative to those with a highquality preparation. Although this ﬁnding has potentially signiﬁcant implications for patient care and healthcare costs, the limitations of the adenoma detection rate as a performance measure and variability in the application of bowel preparation ratings are important issues that must be considered. Am J Gastroenterol 2014; 109:1725–1727; doi:10.1038/ajg.2014.328
Colorectal cancer is the second leading cause of cancer death in the United States (1). Of the modalities used for colorectal cancer screening, only colonoscopy can prevent cancer by removing precursor lesions from the entire colon. The adenoma detection rate (ADR), defined as the percentage of individuals with at least one adenoma identified during endoscopy, was established as a quality indicator by the US Multi-Society Task Force (MSTF) in 2002 (2) and has been demonstrated to be significantly associated with the risk of interval colorectal cancer and cancer death after colonoscopy
(3,4). Although adenoma detection is an important measure of the technical competence of an endoscopist, it clearly can be negatively impacted by lower-quality bowel preparation (5,6). Therefore, endoscopists must decide on the appropriate course of action when faced with a patient with a suboptimal bowel preparation. In 2012, the MSTF guidelines recommended repeat examination in 1 year in most cases of poor-quality bowel preparation (7). For those cases where the bowel preparation is deemed fair but adequate to detect lesions >5 mm, and where small (5 mm lesion or if adenomas 5 mm, the colonoscopy should be repeated within 1 year (18). These early exams do have negative implications for patients (e.g., inconvenience, discomfort, complications) and health-care resource utilization, which must be weighed against the concern for missed lesions. Perhaps one of the most important aspects of the paper by Clark et al. (9) is that it highlights some basic problems with the performance of colonoscopy. First, as substantial variability exists in the evaluation of bowel preparation quality, endoscopists should learn and adopt validated bowel preparation scales, which should be applied only after intraprocedural cleansing. Second, further research is needed to better define when an exam is truly adequate such that standard guideline recommendations for screening and surveillance intervals can be followed. However, most importantly, the large percentage of colonoscopies with low or intermediate-quality bowel preparation indicates the need for universal adoption of strategies to improve the bowel preparation, such as split-dose regimens (18) and thorough intraprocedural cleansing. Simply finding a way to assure adequate-quality bowel preparation for all individuals undergoing colonoscopy will lead to a reduction in both interval cancers and early repeat colonoscopies.
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This material is the result of work supported in part by resources from The Veterans Health Administration. The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs. CONFLICT OF INTEREST
Guarantor of the article: Jason A. Dominitz, MD, MHS. Specific author contributions: Peter Liang and Jason Dominitz certify that each had a role in conceiving, initiating, and writing up of the manuscript. Financial support: P.L. is supported by NIH T32 DK007742. All other financial support has been disclosed. We received no editorial assistance in support of the preparation of the manuscript. Potential competing interests: There are no other relationships that may have any potential competing interests with respect to the manuscript. REFERENCES 1. Siegel R, Ma j, Zou Z et al. Cancer statistics, 2014. CA Cancer J Clin 2014;64:9–29. 2. Rex DK, Bond JH, Winawer S et al. 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 Gastroenterol 2002;97:1296–308. 3. Corley DA, Jensen CD, Marks AR et al. Adenoma detection rate and risk of colorectal cancer and death. N Engl J Med 2014;370:1298–306. 4. Kaminski MF, Regula J, Kraszewska E et al. Quality indicators for colonoscopy and the risk of interval cancer. N Engl J Med 2010;362: 1795–803. 5. Froehlich F, Wietlisbach V, Gonvers J-J et al. Impact of colonic cleansing on quality and diagnostic yield of colonoscopy: the European panel of appropriateness of gastrointestinal endoscopy European multicenter study. Gastrointest Endosc 2005;61:378–84.
© 2014 by the American College of Gastroenterology
6. Adler A, Wegscheider K, Lieberman D et al. Factors determining the quality of screening colonoscopy: a prospective study on adenoma detection rates, from 12,134 examinations (Berlin colonoscopy project 3, BECOP-3). Gut 2013;62:236–41. 7. Lieberman DA, Rex DK, Winawer SJ et al. Guidelines for colonoscopy surveillance after screening and polypectomy: a consensus update by the US multi-society task force on colorectal cancer. Gastroenterology 2012;143:844–57. 8. Menees SB, Kim HM, Elliott EE et al. The impact of fair colonoscopy preparation on colonoscopy use and adenoma miss rates in patients undergoing outpatient colonoscopy. Gastrointest Endosc 2013;78:510–6. 9. Clark BT, Rustagi T, Laine L. What level of bowel prep quality requires early repeat colonoscopy: systematic review and meta-analysis of the impact of prep quality on adenoma detection rate. Am J Gastroenterol 2014;109:1714–23 (this issue). 10. Aronchick CA, Lipshutz WH, Wright SH et al. A novel tableted purgative for colonoscopic preparation: efficacy and safety comparisons with colyte and fleet phospho-soda. Gastrointest Endosc 2000;52:346–52. 11. Wang HS, Pisegna J, Modi R et al. Adenoma detection rate is necessary but insufficient for distinguishing high versus low endoscopist performance. Gastrointest Endosc 2013;77:71–8. 12. Rex DK, Ahnen DJ, Baron JA et al. Serrated lesions of the colorectum: review and recommendations from an expert panel. Am J Gastroenterol 2012;107:1315–29.quiz 1314, 1330 13. Nishihara R, Wu K, Lochhead P et al. Long-term colorectal-cancer incidence and mortality after lower endoscopy. N Engl J Med 2013;369:1095–105. 14. Rostom A, Jolicoeur E. Validation of a new scale for the assessment of bowel preparation quality. Gastrointest Endosc 2004;59:482–6. 15. Lai EJ, Calderwood AH, Doros G et al. The Boston bowel preparation scale: a valid and reliable instrument for colonoscopy-oriented research. Gastrointest Endosc 2009;69:620–5. 16. Calderwood AH, Jacobson BC. Comprehensive validation of the Boston Bowel Preparation Scale. Gastrointest Endosc 2010;72:686–92. 17. Larsen M, Hills N, Terdiman J. The impact of the quality of colon preparation on follow-up colonoscopy recommendations. Am J Gastroenterol 2011;106:2058–62. 18. Johnson DA, Barkun A, Cohen LB et al. Optimizing adequacy of bowel cleansing for colonoscopy: recommendations from the US multi-society task force on colorectal cancer. Am J Gastroenterol 2014;109:1528–45.
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