BACKGROUND: Abdominal aortic aneurysm (AAA) is an important cause of death in Canada, and about 80% of the deaths are due to ruptured aneurysm. METHOD: To determine the most cost-effective way of controlling AAA in terms of early detection and clinical management, a cohort analysis was undertaken beginning at age 50 years, using a multistate life-table model with parameters derived from published articles. The model was used to determine (a) the optimum size for elective surgery and (b) the optimum rate of detection of intact AAA. Cost per quality-adjusted life-year (QALY) was used to measure outcome. RESULTS: The most cost-effective diameter for repair of an intact AAA increases with age between the limits of 55 and 70 mm. The predominant size for repair is 60 mm. The most cost-effective rate at which latent AAA should be detected is 20% per year, corresponding to a screening interval of 5 years. Selective screening by sex or smoking status, or both, does not improve cost-effectiveness. CONCLUSIONS: Primary care patients aged 50 years and over should be offered abdominal ultrasonography every 5 years. Those with AAA should be kept under surveillance and offered elective surgery when the aneurysm reaches 60 mm in diameter.
BACKGROUND:Abdominal aortic aneurysm (AAA) is an important cause of death in Canada, and about 80% of the deaths are due to ruptured aneurysm. METHOD: To determine the most cost-effective way of controlling AAA in terms of early detection and clinical management, a cohort analysis was undertaken beginning at age 50 years, using a multistate life-table model with parameters derived from published articles. The model was used to determine (a) the optimum size for elective surgery and (b) the optimum rate of detection of intact AAA. Cost per quality-adjusted life-year (QALY) was used to measure outcome. RESULTS: The most cost-effective diameter for repair of an intact AAA increases with age between the limits of 55 and 70 mm. The predominant size for repair is 60 mm. The most cost-effective rate at which latent AAA should be detected is 20% per year, corresponding to a screening interval of 5 years. Selective screening by sex or smoking status, or both, does not improve cost-effectiveness. CONCLUSIONS: Primary care patients aged 50 years and over should be offered abdominal ultrasonography every 5 years. Those with AAA should be kept under surveillance and offered elective surgery when the aneurysm reaches 60 mm in diameter.