Comparing the Real-World Effectiveness of High- Versus Low-Volume Split Colonoscopy Preparations: An Experience Through the British Columbia Colon Cancer Screening Program

Background The British Columbia Colon Screening Program (BCCSP) is a population-based colon cancer screening program. In December 2018, physicians in Vancouver, Canada agreed to switch from a low-volume split preparation to a high-volume polyethylene glycol preparation after a meta-analysis of studies suggested superiority of the higher volume preparation in achieving adequate bowel cleansing and improving adenoma detection rates. Aims To compare the quality of bowel preparation and neoplasia detection rates using a high-volume split preparation (HVSP) versus a low-volume split preparation (LVSP) in patients undergoing colonoscopy in the BCCSP. Methods A retrospective review of patients undergoing colonoscopy through the BCCSP at St. Paul’s Hospital from July 2017 to November 2018 and December 2018 to November 2019 was conducted. Inclusion criteria included age 50 to 74 and patients undergoing colonoscopy through the BCCSP. Variables collected included patient demographics and bowel preparation quality. Rates of bowel preparation and neoplasia detection were analyzed using chi-squared test. Results A total of 1453 colonoscopies were included, 877 in the LVSP group and 576 in the HVSP group. No statistically significant difference was noted between rates of inadequate bowel preparation (LVSP 3.6% versus HVSP 2.8%; P = 0.364). Greater rates of excellent (48.4% versus 40.1%; P = 0.002) and optimal (90.1% versus 86.5%; P = 0.041) bowel preparation were achieved with HVSP. The overall adenoma detection rate was similar between the two groups (LVSP 53.1% versus HVSP 54.0%; P = 0.074). LVSP demonstrated higher overall sessile serrated lesion detection rate (9.5% versus 5.6%; P = 0.007). Conclusions Compared to LVSP, HVSP was associated with an increase in excellent and optimal bowel preparations, but without an improvement in overall neoplasia detection.