Aspirin may decrease colorectal cancer incidence, but its role as an adjunct to or substitute for screening has not been evaluated.To examine the potential cost-effectiveness of aspirin chemoprophylaxis in relation to screening.Markov model.Literature on colorectal cancer epidemiology, screening, costs, and aspirin chemoprevention (1980-1999).General U.S. population.50 to 80 years of age.Third-party payer.Aspirin therapy in patients screened with sigmoidoscopy every 5 years and fecal occult blood testing every year (FS/FOBT) or colonoscopy every 10 years (COLO).Discounted cost per life-year gained.When a 30% reduction in colorectal cancer risk was assumed, aspirin increased costs and decreased life-years because of related complications as an adjunct to FS/FOBT and cost $149 161 per life-year gained as an adjunct to COLO. In patients already taking aspirin, screening with FS/FOBT or COLO cost less than $31 000 per life-year gained.Cost-effectiveness estimates depended highly on the magnitude of colorectal cancer risk reduction with aspirin, aspirin-related complication rates, and the screening adherence rate in the population. However, when the model's inputs were varied over wide ranges, aspirin chemoprophylaxis remained generally non-cost-effective for patients who adhere to screening.In patients undergoing colorectal cancer screening, aspirin use should not be based on potential chemoprevention. Aspirin chemoprophylaxis alone cannot be considered a substitute for colorectal cancer screening. Public policy should focus on improving screening adherence, even in patients who are already taking aspirin.
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View details for PubMedID 11694102