Colonoscopic surveillance after polypectomy: considerations of cost effectiveness

To assess the cost effectiveness of the current recommendation that persons who have had an adenomatous colon polyp removed have periodic colonoscopic surveillance at fixed and regular intervals.

Cost-effectiveness analysis using data from the medical literature in a simulation model to estimate the costs of and the risk for perforation associated with periodic colonoscopic surveillance for a 50-year-old man followed for 30 years.

A program of colonoscopy every 3 years would incur cumulatively a 1.4% risk for colon perforation, a 0.11% risk for perforation-related death, and direct physician costs of $2071 for colonoscopy (discounted at 5%). If a 50-year-old man's cumulative remaining risk for death from cancer is 2.5% after the removal of a single small adenoma and if effectiveness of colonoscopic surveillance every 3 years is 100%, then one death from cancer could be prevented by doing 283 colonoscopies, incurring 0.6 perforations, 0.04 perforation-related deaths, and direct physician costs of $82,000. If surveillance were 50% effective and the cumulative remaining risk for death from cancer were 1.25%--a plausible scenario--1131 colonoscopies would be required to prevent one death from cancer, incurring 2.3 perforations, 0.17 perforation-related deaths, and physician costs of $331,000.

The cost effectiveness of colonoscopic surveillance is very sensitive to estimates of the cumulative remaining risk for death from cancer after polypectomy as well as to surveillance efficacy. For persons whose remaining risk for death from cancer may be low, such as persons with a single small adenoma, recommendations for colonoscopic surveillance at fixed and regular intervals may be excessively costly.