The potential for a selective screening strategy for abdominal aortic aneurysm

Objectives-To investigate the feasibility of selective screening for abdomi nal aortic aneurysm (AAA) based on identification of a target group of mana geable size defined by risk factors for AAA. Setting-Male residents of Perth, Western Australia, aged 65-83 years, who p articipated in a randomised controlled trial of ultrasound screening for AA A. Methods-Eligible men were identified from the electoral roll and invited to attend a screening clinic. Those who attended completed a questionnaire, h ad a limited physical examination, and underwent an ultrasound examination to identify the maximum diameter of the infrarenal aorta. Data on risk fact ors collected from the first 8995 men seen were used to calculate a multiva riate risk score for the remaining 2755 men who were screened. Gentiles of the risk score were used to define potential target groups for screening an d the sensitivity and specificity of each of these selective screening stra tegies were calculated. We repeated the calculation separately for AAAs of at least 30 mm, 40 mm, and 50 mm in diameter. Results-We found that screening half of the male population aged 65-83 year s would find approximately 75% of AAAs, regardless of their size, whereas s creening only current smokers in this population would find approximately 2 0% of AAAs. Conclusions-Selective screening for AAA using easily recognisable risk fact ors is feasible but is not worthwhile as approximately 25% of clinically si gnificant cases would be missed.