The Impact of Bowel Cleansing on Follow-up Recommendations in Average-Risk Patients With a Normal Colonoscopy

Stacy B Menees, MD, MS; Eric Elliott, MPH; Shail Govani, MD; Constantinos Anastassiades, MD; Stephanie Judd, MD; Annette Urganus, MPH; Suzanna Boyce, MPA; Philip Schoenfeld, MD, MSEd, MSc (Epi)


Am J Gastroenterol. 2014;109(2):148-154. 

In This Article

Abstract and Introduction


Objectives. Repeat colonoscopy in 10 years after a normal screening colonoscopy is recommended in an average-risk patient, and it has been proposed by American Gastroenterological Association (AGA), American College of Gastroenterology (ACG), and American Society for Gastrointestinal Endoscopy (ASGE) as a quality measure. However, there are little quantitative data about adherence to this recommendation or factors that may improve adherence. Our study quantifies adherence to this recommendation and the impact of suboptimal bowel preparation on adherence.

Methods. In this retrospective database study, endoscopy reports of average-risk individuals ≥50 years old with a normal screening colonoscopy were reviewed. Quality of colon cleansing was recorded using the Aronchick scale as excellent, good, fair, or poor. Main outcome measurements were quality of bowel preparation and recommendation for timing of repeat colonoscopy. Recommendations were considered consistent with guidelines if 10-year follow-up was documented after excellent, good, or fair prep or if ≤1-year follow-up was recommended after poor prep.

Results. Among 1,387 eligible patients, recommendations for follow-up colonoscopy inconsistent with guidelines were seen in 332 (23.9%) subjects. By bowel preparation quality, 15.3% of excellent/good, 75% of fair, and 31.6% of poor bowel preparations were assigned recommendations inconsistent with guidelines (P<0.001). Patients with fair (odds ratio=18.0; 95% confidence interval 12.0–28.0) were more likely to have recommendations inconsistent with guidelines compared with patients with excellent/good preps.

Conclusions. Recommendations inconsistent with guidelines for 10-year intervals after a normal colonoscopy occurred in >20% of patients. Minimizing "fair" bowel preparations may be a helpful intervention to improve adherence to these recommendations.


Colonoscopy is the primary modality for prevention of colorectal cancer (CRC) per multisociety guidelines,[1] and the cost effectiveness of CRC screening with colonoscopy is primarily dependent on high-quality baseline examination and adherence to guideline recommendations for timing of repeat screening colonoscopy.[2] Of course, guideline recommendations are not followed in every patient and endoscopists do not always recommend 10-year intervals after a normal screening colonoscopy in an average-risk patient.[3–5] However, endoscopists' adherence to these guideline recommendations will come under close scrutiny very soon.

Currently, endoscopists are asked to simply report different quality indicators, such as cecal intubation or adenoma detection rate, to Centers for Medicare and Medicaid Services (CMS) through the Physician Quality Reporting System (PQRS). CMS proposed a new quality measure for the 2013 PQRS: frequency of recommending repeat colonoscopy in 10 years after a normal colonoscopy in an average-risk patient.[6] When endoscopists report this and multiple other quality indicators, they receive a small bonus in Medicare payments. By 2014, failure to report will result in a reduction in Medicare payments. However, this system does not account for the actual quality of performance of colonoscopy; it only requires reporting of quality indicators. It does not adjust payment for services based upon successfully meeting numeric thresholds for quality indicators (e.g., cecal intubation in >95% of colonoscopies for CRC screening). However, by 2015, a value-based quality index is to be enacted where endoscopists' success at achieving multiple quality indicators will be quantified and payments for colonoscopy will be adjusted based on this to-be-determined formula.

What should be the threshold for recommending a 10-year interval after a normal screening colonoscopy? Over 80% of cases? Over 90%? Quantifiable data will be needed to set appropriate numerical thresholds. Also, one purpose of quality indicators is to improve performance, and hence it is important to identify factors associated with suboptimal performance that can be addressed through quality improvement programs.

Lack of knowledge about guideline recommendations is not an issue based upon survey studies.[5,7] However, endoscopists vary from guideline recommendations when the bowel preparation is suboptimal and they are concerned that adenomas could be missed. This is an understandable concern. Compared with "fair" or "suboptimal" bowel preparation, "excellent" or "optimal" bowel preparation improves identification of polyps.[8–11] Based on survey studies using hypothetical patient scenarios and photographs of bowel preparation, increasingly shorter intervals for repeat colonoscopy are recommended for worse categories of bowel cleansing.[12,13] Although this reflects "self-reported" practices and may be prone to response bias,[14–16] it supports the rationale that quality of bowel preparation affects adherence to guideline recommendations.[17]

The aim of our study is to quantify frequency of adherence to recommending repeat colonoscopy in 10 years after a normal screening colonoscopy in an average-risk patient and to assess the impact of bowel preparation quality, demographic factors, and procedural factors on adherence to guideline recommendations. We hypothesize that fair bowel preparation is highly associated with recommendations to repeat colonoscopy sooner than 10 years.