Researchers have provided an objective definition of adequate bowel preparation for screening or surveillance colonoscopy using a quantitative, validated scale.
“Guidelines define adequate bowel preparation as the ability of the endoscopist to identify polyps greater than 5 mm. However, no study has determined a quantifiable measure of the level of bowel preparation quality at which visualization of polyps larger than 5 mm is unacceptably decreased,” the researchers wrote, calling this lack of information “a major flaw in the current practice of colonoscopic screening and surveillance.”
The research team therefore used the Boston Bowel Preparation Scale (BBPS) to provide an objective definition of adequate bowel preparation quality to better identify patients who need early repeat colonoscopy. They collected data on 438 male veterans aged 50 to 75 years (1,161 colon segments analyzed) who underwent screening or surveillance colonoscopy and then repeat colonoscopy within 60 days by a different endoscopist masked to the previous findings at the West Haven Veterans Affairs Medical Center from January 2014 to February 2015.
After the procedure, endoscopists scored the left colon, transverse colon and right colon segments on an ascending quality scale of 0 to 3, and also recorded whether they would recommend early repeat colonoscopy or not. The proportion of colon segments with adenomas larger than 5 mm missed at first colonoscopy served as the primary endpoint.
At first colonoscopy 79.2% of patients had BBPS scores of 2 or higher in all segments.
The adjusted proportion of missed adenomas larger than 5 mm was 5.2% for segments with BBPS scores of 2 vs. 5.6% for those with BBPS scores of 3 (difference, – 0.4%; 95% CI, – 2.9%-2.2%). Therefore, a score of 2 was noninferior to a score of 3. Conversely, a score of 1 was inferior to scores of 2 and 3.
Overall, 15.9% of segments with BBPS scores of 1 had missed adenomas larger than 5 mm compared with 5.6% of segments with BBPS scores of 3 (difference, 10.3%; 95% CI, 2.7%-17.9%) and compared with 5.2% of segments with BBPS scores of 2 (difference, 10.7%; 95% CI, 3.2%-18.1%).
Screening and surveillance intervals changed from the first colonoscopy in 16.3% of patients with BBPS scores of 3 in all segments, for 15.3% with BBPS scores of 2 or 3 in all segments, and for 43.5% of patients with a BBPS score of 1 in at least one segment.
These findings support “a recommendation for early repeat colonoscopic evaluation in patients with a BBPS score of 0 or 1 in any colon segment,” the researchers concluded. “Implementation of these recommendations may help optimize the value-based delivery of colonoscopy for colorectal cancer screening and surveillance and assist in standardizing practice among gastroenterologists.”
“Those who perform colonoscopy should use validated scoring systems to report the quality of bowel preparation and should adhere to guideline recommendations for surveillance when the preparation is deemed adequate,” Philip Schoenfeld, MD, from Ann Arbor Veterans Health Care System, University of Michigan School of Medicine, and Jason A. Dominitz, MD, from the VA Puget Sound Health Care System, University of Washington School of Medicine, wrote in a related editorial. “Thanks to Clark et al, we now have long overdue data that define what qualifies for an “adequate” bowel preparation. Until and unless other bowel preparation scoring systems are likewise studied, these findings should encourage the widespread adoption of the BBPS, which is a validated, quantitative scale that can be easily learned.” – by Adam Leitenberger
Disclosure: The researchers report no relevant financial disclosures.