Bowel Preparation for Colonoscopy: A Comparative CostEffective Analysis of Traditional Per OS Purgatory Prep Versus a Novel Method Using High-Volume Colonic Water Irrigation

Objectives: Colonoscopy remains the cornerstone for colorectal screening as well as the diagnostic test of choice for positive screening tests or to further investigate the underlying etiology for various symptoms. The efficacy of colonoscopy hinges on an adequate preparation. Unfortunately, upwards of ¼ of colonoscopies performed have an inadequate prep. The economic burden, considering both indirect and direct costs, of an inadequate bowel preparation remains unknown. Recently a novel method of bowel preparation for colonoscopy has been made available using a FDAcleared high volume rectal irrigation device. The aim of this study is to perform a cost-effective analysis of high volume rectal water irrigation bowel preparation for colonoscopy and compare it to traditional preparations taking into account all direct and indirect costs.Methods: A Markov cost-effectiveness model was developed comparing two bowel preparation regimens (split-dose PEG-ELS preparation vs. high volume rectal water irrigation) using a hypothetical cohort of 100,000 average-risk 50- year-old United States(US) persons undergoing a screening colonoscopy. Clinical estimates and transitional probabilities simulating the natural history of colorectal cancer and performance statistics were derived. Direct costs were based on average reimbursement by the Centers for Medicare and Medicaid services. Indirect costs related to time spent by the patient an adult family member in preparing for colonoscopy was estimated by using the human capital method and available willingness to pay estimates. The average cost of travel was also included in the analysis. Results: Use of novel high-volume rectal irrigation for colonoscopy preparation proved to be superior in cost (direct and indirect) when compared to traditional per OS purgatory preparation. Conclusion: There is a significant economic burden associated with an inadequate bowel preparation. Use of high volume rectal irrigation for colon preparation is much more cost effective compared to traditional preparation when considering both direct and indirect costs over the long term period.