CT Colonography Versus Optical Colonoscopy: Cost-Effectiveness in Colorectal Cancer Screening

Purpose: CT colonography (CTC) has been accepted as an optical colonoscopy (OC) alternative for colorectal cancer (CRC) screening by some guidelines, while others maintain that the data is insufficient. CTC’s less invasive nature may improve compliance; however, cost and need for colonoscopy, if lesions are detected, remain an obstacle for implementation. As a result, the authors set out to determine the cost-effectiveness of CTC in the context of its drawbacks and advantages when compared with OC within a Canadian context. Methods: Using a decision analysis software, an economic analysis was performed comparing CTC to OC for CRC screening in asymptomatic patients. The 10-year primary outcome measure was study cost, cost difference of screening 100,000 patients, and the cost of one quality adjusted life year gained. The sensitivities, specificities, and polyp prevalence rates were derived from literature. The cost of each test was derived from local data. Results: Local cost of OC is 764.36 CAD compared to 580.01 CAD for CTC. In the case of a normal OC, reassessment would not be necessary for 10 years, whereas in an asymptomatic average-risk population CTC must be repeated every 5 years. The incremental cost-effectiveness ratio, or the additional cost per life year of OC compared to CTC was calculated to be 3,390.76 CAD.