The quality of colorectal cancer (CRC) screening with colonoscopy is primarily dependent on high-quality baseline examinations, whereas cost-effectiveness of CRC screening is more dependent on adherence to guideline recommendations for timing of repeat screening and surveillance colonoscopy. Guideline recommendations should be followed in most, but not all, patients. Endoscopists (physicians who perform endoscopic procedures including colonoscopy) may occasionally vary from guidelines, which state that average-risk patients with one to two small (< 1 cm) adenomas (precancerous polyps) on screening colonoscopy should be told to get surveillance colonoscopy in five to ten years or to get repeat colonoscopy in ten years if only one to two small hyperplastic (noncancerous) polyps are found. However, the frequency of endoscopists' recommending repeat colonoscopy sooner than recommended by guidelines will be scrutinized closely in the coming years as different components of the Affordable Care Act are enacted.
"The aim of our study was to quantify the frequency of appropriate follow-up colonoscopy recommendations after one to two polyps were found during screening colonoscopy in average-risk patients. In addition, we aimed to identify factors associated with adherence to guideline recommendations, including bowel preparation quality, demographic factors and procedural factors," said study lead author Stacy B. Menees, MD, University of Michigan Health System. "We found that more than 90 percent of endoscopists' recommendations for timing of surveillance colonoscopy in average-risk patients with one to two small polyps were consistent with guideline recommendations. Quality of preparation was strongly associated with deviation from guideline recommendations."
The researchers' objective was to quantify adherence to recommended surveillance colonoscopy intervals and to identify factors associated with lack of adherence. This was a retrospective endoscopic database analysis from the University of Michigan in-hospital medical procedure unit, two University of Michigan outpatient amubulatory surgery centers and the Ann Arbor Veterans Affairs Health Care System in-hospital endoscopy suite. Between January 1, 2009 and December 31, 2009, average-risk individuals age 50 or over undergoing screening colonoscopy found to have one to two small polyps on screening colonoscopy were included in the study. The main outcome measurements were frequency of recommending repeat colonoscopy in five years if one to two small adenomas were found and in ten years if hyperplastic polyps were found.
Of 922 outpatient screening colonoscopies with one to two small polyps found, 90.2 percent received appropriate recommendations for timing of repeat colonoscopy. Eighty-four percent of patients with one to two small adenomas and 94 percent of patients with one to two hyperplastic polyps received recommendations that were consistent with guidelines. Based on logistic regression analysis, patients older than 70 years, fair bowel preparation, poor bowel preparation, and the presence of two small adenomas versus one small adenoma were factors associated with recommendations inconsistent with guidelines.
This study adds to the growing body of research about why endoscopists recommend repeat colonoscopies sooner than indicated by guidelines. Endoscopists appear to recommend repeat colonoscopy sooner when bowel preparation is fair or worse because they are understandably concerned that small adenomas might have been missed. Other possible reasons for repeating colonoscopy sooner than recommended include if patients are at higher risk for CRC (ie, over 70 years old) or if the endoscopist is concerned about the limitations of colonoscopy to prevent CRC in the right side of the colon (i.e. recommend repeat colonoscopy sooner than five years if two small flat adenomas were found in the ascending colon). Some endoscopists simply may distrust research used to support guideline recommendations or be concerned about medicolegal issues. Ultimately, a combination of qualitative research with endoscopists and quantitative database research with endoscopist-specific characteristics needs to be conducted to clarify this topic.
The researchers stated that these findings provide a starting point to establish targets or benchmarks for frequency of adherence to guideline recommendations. This may contribute to the development of quality improvement programs and national benchmarks by organizations such as the Centers for Medicare & Medicaid Services. Fair bowel cleansing was strongly associated with recommendations inconsistent with guidelines. This suggests that interventions that improve the quality of bowel preparation may improve adherence to guideline recommendations.