Screening for abdominal aortic aneurysm: lessons from a population-based study

Objectives: To test the acceptability of screening and to identify modifiab le risk factors for abdominal aortic aneurysm (AAA) in men. Design: A trial of ultrasound screening for AAA in a population-based rando m sample of men aged 65-83 years, and a cross-sectional case-control compar ison of men in the same sample. Participants: 12203 men who had an ultrasound examination of their abdomina l aorta, and completed a questionnaire covering demographic, behavioural an d medical factors. Main outcome measures: Prevalence of AAA, and independent associations of A AA with demographic, medical and lifestyle factors. Results: Invitations to screening produced a corrected response of 70.5%. T he prevalence of AAAs (> 30 mm) rose from 4.8% in men aged 65-69 years to 1 0.8% in those aged 80-83 years. The overall prevalence of large (> 50 mm) a neurysms was 0.69%. In a multivariate logistic model Mediterranean-born men had a 40% lower risk of AAA (> 30 mm) compared with men born in Australia (odds ratio [OR], 0.6; 95% CI, 0.4-0.8), while ex-smokers had a significant ly increased risk of AAA (OR, 2.3; 95% CI, 1.9-2.8), and current smokers ha d even higher risks. AAA was significantly associated with established coro nary and peripheral arterial disease and a waist:hip ratio greater than 0.9 ; men who regularly undertook vigorous exercise had a lower risk (OR, 0.8; 95% CI, 0.7-1.0). Conclusion: Ultrasound screening for AAA is acceptable to men in the likely target population. AAA shares some but not all of the ri sk factors for occlusive vascular disease, but the scope for primary preven tion of AAA in later life is limited.