Screening for abdominal aortic aneurysms.

Ruptured aneurysm of the abdominal aorta is a common preventable cause of death, accounting for 2% of all deaths in men over 60 years of age. Population screening could prevent such deaths. Aortic diameter (which can be measured accurately on ultrasound) is a strong predictor of the risk of rupture, which is about 17% per year with aortic diameter > or = 6 cm, but below 0.5% per year with aortic diameter < 5 cm, with uncertainty regarding risk in the range 5.0-5.9 cm. Adopting an aortic diameter cut-off of 6.0 cm, the detection rate is estimated to be 86% (that is, 86% of all men who would rupture an aortic aneurysm could be identified and offered surgery) and the false positive rate only 0.6% (that is, 0.6% of men who would not rupture an aortic aneurysm would be so identified). In men with aortic diameter > or = 6 cm, the risk of rupture of 17% per year greatly outweighs the peri-operative mortality of about 5%. A national screening programme for men over 60 years of age could prevent 2000 deaths per year and should commence. Uncertainty remains regarding the frequency with which men with smaller aneurysms should be re-examined and the value of intervention among those with an aortic diameter of 5.0-5.9 cm, but the screening programme itself would generate data to help resolve these issues.