Ultrasonographic screening for abdominal aortic aneurysm: analysis of surgical decisions for cost-effectiveness

A mathematic model is created to determine the economic cost per year of anticipated prolongation of life that would result from a program of abdominal ultrasonographic (US) screening for abdominal aortic aneurysm. The protocol involves US screening at age 60, 67, and 74 years with additional annual follow-up US and examination if an aneurysm of less than 40 mm is detected. Larger aneurysms are assumed to be sent for early elective resection. The benefits and risks for a subset of men with symptoms of intermittent claudication (IC) as an additional risk factor of atherosclerosis is calculated for comparison. Many of the factors on which these calculated costs and benefits are based are approximations and inferences. These include operative mortality for elective and emergent cases, charges for each such condition, cost of US, and anticipated survival following successful aneurysmectomy both with and without concomitant IC. Sensitivity analysis is performed to show how variations in the major parameters alter the outcome of the calculated cost per year of anticipated extension of life.