Objective: To assess the cost effectiveness of a periodic program of colorectal cancer screening in the elderly.
Design: A model was constructed of four strategies for the periodic screening of persons 65 to 85 years of age. The effect of each strategy on life expectancy and health care costs was estimated under assumptions that were uniformly unfavorable to screening. Cost and added years of life were discounted at 5% per year. Cost per year of life gained from screening was calculated for each screening strategy.
Data sources: Assumptions used in the model were based on a review of pertinent studies; those studies with results more unfavorable to screening were given more weight. Strengths and weaknesses of studies are discussed.
Main results: A program of annual fecal occult blood testing (FOBT) in the elderly would detect at least 17% of the expected cases of cancer and could cost $35,000 per year of life saved. Screening schedules that include periodic sigmoidoscopy would prevent more cases of cancer but could cost between $43,000 and $47,000 per year of life gained. These estimates are based on uncertain assumptions, but results were not extremely sensitive to further relaxation of the values of the most uncertain assumptions. In no case did the cost per year of life gained from annual FOBT exceed $55,000 or did the cost per year of life gained from FOBT with sigmoidoscopy every 5 years exceed $61,000.
Conclusions: Although colorectal cancer screening is costly in the aggregate, its potential medical benefits make it a reasonably cost-effective preventive intervention for the elderly.