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 (3(1/2)-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 chi(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.