Objective To determine whether screening Danish men aged 65 or more for abdominal aortic aneurysms reduces mortality. Design Single centre randomised controlled trial. Setting All five hospitals in Viborg County, Denmark. Participants All 12 639 men born during 1921-33 and living in Viborg County. In 1994 we included men born 1921-9 (64-73 years). We also included men who became 65 during 1995-8. Interventions Men were randomised to the intervention group (screening by abdominal ultrasonography) or control group. Participants with an abdominal aortic aneurysm > 5 cm were referred for surgical evaluation, and those with smaller aneurysms were offered annual scans. Outcome measures Specific mortality due to abdominal aortic aneurysm, overall mortality, and number of planned and emergency operations for abdominal aortic aneurysms. Results 4860 of 6333 men were screened (attendance rate 76.6%). 191 (4.0% of those screened) had abdominal aortic aneurysms. The mean follow-up time was 52 months. The screened group underwent 75% (95% confidence interval 51% to 91%) fewer emergency operations than the control group. Deaths due to abdominal aortic aneurysms occurred in nine patients in the screened group and 27 in the control group. The number needed to screen to save one life was 352. Specific mortality was significantly reduced by 67% (29% to 84%). Mortality due to non-abdominal aortic aneurysms was non-significantly reduced by 8%. The benefits of screening may increase with time. Conclusion Mass screening for abdominal aortic aneurysms in Danish men aged 65 or more reduces mortality.

screening appears to reduce hospital AAA mortality and to be cost-effective.

US seems to be a valid screening method for AAA. Screening for proximal infrarenal aorta aneurysm remains acceptable because the majority of aortic diameters in this segment are so much smaller than the diameters that define an AAA.

P-MMP9 and P-alpha 1 antitrypsin may predict the natural history of AAA.

The offer of screening causes transient psychological stress in subjects found not to have AAA. However, diagnosis of an AAA seems to impair QL permanently and progressively in conservatively treated cases. This impairment seems reversible by operation. Nevertheless, the impairment seems considerable, and must be considered in the management of AAA and in the final evaluation of screening for AAA.