Comparison of various strategies for colorectal cancer screening tests.

Introduction Colorectal cancer (CRC) is one of the most serious health problems worldwide and thus it is important to assess health and economic impacts of preventative CRC screening strategies. Methods For this reason, a theoretical model based on Markov chains is proposed to compare these strategies: fecal occult blood test, capsule endoscopy, once-life and twice-life colonoscopy, and no screening. The model predicts the health state of a population of individuals aged from 50 to 75 years. Results The numerical results show that the optimal timing for a once-lifetime colonoscopy screening method is before the age of 50 and that the twice-lifetime colonoscopy is the best screening strategy with respect to CRC incidence. In contrast, it is the most expensive one if the CRC treatment costs are not included. The model predicts that there is a minimal CRC incidence in the population when the second colonoscopy is appropriately timed. By using specific data, this age was found to be 59 years. Conclusion The screening strategies probably save expenses on the treatment of the population and at the same time decreases mortality. Optimized twice-lifetime colonoscopy seems to be the most efficient strategy with respect to mortality and overall costs including subsequent treatment. Eur J Gastroenterol Hepatol 23:1157-1164 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.