Background Abdominal aortic aneurysm (AAA) is known to be associated w
ith various diseases, especially hypertension, acute myocardial infarc
tion (AMI), chronic obstructive airway disease (GOAD), and intermitten
t claudication. These associations have led to a debate about whether
screening of older men for AAA should be restricted to those with an a
ssociated disease. Methods To compare mass screening of men for AAA wi
th screening of men with AAA-associated diseases, all previous compute
rized hospital-recorded AAA-associated diseases were merged with the r
esults of mass screening of 4404 men aged 65-73 years. Results Of hype
rtensives, 826 per cent attended screening, of whom 17.8 per cent had
AAA. For previous AMI the equivalent values were 82.3 and 9.3 per cent
; for COAD 74.3 and 7.7 per cent; for angina pectoris 83.8 and 7.5 per
cent; for lower limb arteriosclerosis 81.1 and 6.1 per cent; and for
stroke or transient cerebral ischaemia 75.0 and 6.2 per cent. Screenin
g of these six high-risk groups alone would have required 78.5 per cen
t fewer scans and 51.1 per cent of the AAAs diagnosed at mass screenin
g would have been recognized. The attendance rate would have been 80.4
per cent, of whom 9.5 per cent would have had an aneurysm. The attend
ance rate among non-high-risk men was 74.7 per cent and 2.7 per cent h
ad an aneurysm. Conclusion If screening for AAA is desirable, the auth
ors recommend mass rather than high-risk screening.