Clinical Question: In older men, does screening for abdominal aortic aneurysm (AAA) result in fewer deaths overall or fewer deaths caused by aneurysm over the next five years?

Setting: Population-based

Study Design: Randomized controlled trial (single-blinded)

Allocation: Uncertain

Synopsis: The researchers conducting this Danish study enrolled all 12,639 men born in years 1921 to 1929 and who lived in a single county. The men were 64.3 to 73.8 years of age (average: 67.7 years) at the time of the study. The men were assigned randomly to a control group or were invited to undergo ultrasonography to screen for the presence of AAA. Nonresponders to the invitation were reinvited once, and 76.6 percent of all invited men underwent screening.

Participants with an AAA of at least 5 cm in diameter (0.5 percent) were referred to a vascular surgeon; men with small AAAs were screened yearly and referred if their aneurysm had increased to 5 cm or more in diameter. There were nine deaths from AAA in the screened group and 27 deaths caused by AAA in the control group over the mean 4.33 years of follow-up. Rates of all-cause mortality in these older men were not affected by screening. These small numbers translate into a number needed to screen of 349 to prevent one AAA-related death over 4.3 years.

Bottom Line: Offering screening to older men will decrease their risk of dying because of an AAA but will not decrease their overall risk of dying within the next 4.3 years. This study evaluated screening in all men; other studies of screening have shown a benefit in men who smoke. (Level of Evidence: 1b)