ASYMPTOMATIC ABDOMINAL AORTIC-ANEURYSM AN D CONCOMITANT END-STAGE RENAL-FAILURE - A DECISION-ANALYSIS

Decision analysis is an explicit and quantitative technique which is p articularly well suited for medical problems involving multiple comple x clinical features. In this article, a decision analysis model was us ed to measure the risks and benefits between different therapeutic opt ions, for a patient with a 4 cm diameter asymptomatic abdominal aortic aneurysm and concomitant end stage renal failure. A Markov model was built to stimulate the natural history of abdominal aortic aneurysm, i ts risk of rupture, and the age-dependent dialysis-related mortality. Despite end-stage renal disease that limits life expectancy and increa ses the surgical risk, the model suggests that surgical resection of t he aneurysm (immediate, or delayed if the diameter exceeds 5 cm in dia meter) would result in greater life expectancy compared with therapeut ic abstention unless the surgical risk exceeds 8.5% and 22%, respectiv ely. Moreover, the gain in life expectancy between immediate and delay ed surgery Is not significant, and individual decision-making between these two options should include additional elements representing pati ents' preference. In conclusion, this model emphasizes the usefulness of decision analysis as a decision aid to medical problem-solving. The Markov simulation, which represents in a realistic manner the natural history of aortic aneurysm, and sensitivity analyses reinforce the cr edibility of this approach.