Screening for Abdominal Aortic Aneurysm Reduces Overall Mortality in Men. A Meta-analysis of the Mid- and Long-term Effects of Screening for Abdominal Aortic Aneurysms

Abstract

Background Four randomised controlled trials of screening older men for abdominal aortic aneurysms (AAA) have been completed. A meta-analysis was performed to examine the pooled effects of screening on both mid- and long-term AAA-related and total mortality, and operations for AAA. Methods Pooled mid-term (3½–5 years) and long term (7–15 years) effects were calculated as odds-ratios (ORs) with 95% confidence intervals in fixed effect models. Long-term data from the West Australian trial were limited to all-caurse deaths. Heterogeneity between the studies was assessed by the χ 2-test. In cases of heterogeneity, random effect models were used. Results The pooled mid-term analysis showed the offer of screening caused a significant reduction in AAA related mortality (OR = 0.56, 95% C.I. 0.44,0.72), and emergency operations (OR = 0.55, 95% C.I.: 0.39; 0.76), while the number of elective operations increased significantly (OR = 3.27, 95% C.I.: 2.14; 5.00). Overall mortality was reduced, but not significantly (OR = 0.94, 95% C.I.: 0.86; 1.02). The long-term results also showed a significant reduction in AAA-related mortality (OR = 0.47, 95% C.I.: 0.25; 0.90), overall mortality (OR = 0.94, 95% C.I.: 0.92; 0.97) and emergency operations (OR = 0.48, 95% C.I.: 0.28; 0.83), while the number of elective operations increased significantly (OR = 2.81, 95% C.I.: 2.40; 3.30). Conclusion Population screening for AAA reduces AAA-related and overall mortality, however local differences may exits which could influence cost effectiveness of screening.