A Sustained Mortality Benefit from Screening for Abdominal Aortic Aneurysm

Abstract

Longer-term mortality benefit and cost-effectiveness for abdominal aortic aneurysm (AAA) screening are uncertain. To estimate the benefits, in terms of AAA-related and all-cause mortality, and cost-effectiveness of ultrasonography screening for AAA in a group that was invited to screening compared with a group that was not invited at a mean 7-year follow-up. Randomized trial. 4 centers in the United Kingdom. Population-based sample of 67,770 men age 65 to 74 years. Patients with an AAA detected at screening had surveillance and were offered surgery after predefined criteria were met. Mortality data were obtained after flagging on the national database. Unit costs obtained from large samples were applied to individual event data for the cost analysis. The hazard ratio was 0.53 (95% CI, 0.42 to 0.68) for AAA-related mortality in the group invited for screening. The rupture rate in men with normal results on initial ultrasonography has remained low: 0.54 rupture (CI, 0.25 to 1.02 ruptures) per 10 000 person-years. In terms of all-cause mortality, the observed hazard ratio was 0.96 (CI, 0.93 to 1.00). At the 7-year follow-up, cost-effectiveness was estimated at $19 500 (CI, $12,400 to $39,800) per life-year gained based on AAA-related mortality and $7600 (CI, $3300 to infinity) per life-year gained based on all-cause death. (All values are reported in U.S. dollars [U.K. 1 pound sterling = U.S. $1.58]). Inclusion of deaths from aortic aneurysm at an unspecified site, which may include some thoracic aortic aneurysms, may have underestimated the treatment effect. These results from a large, pragmatic randomized trial show that the early mortality benefit of screening ultrasonography for AAA is maintained in the longer term and that the cost-effectiveness of screening improves over time. International Standard Randomized Controlled Trial registration number: ISRCTN37381646.