Optimising Abdominal Aortic Aneurysm Screening of 65 Year Old Men by Exploring Risk Factor Based Targeted Screening Strategies in Light of Declining Prevalence of the Disease.

Abstract

Objective: A decline in abdominal aortic aneurysm (AAA) prevalence calls into question the credibility of general population screening of 65 year old men. Selectively targeting high risk individuals among this group could be more effective in preventing death from AAA rupture. This cross sectional study analysed risk factor data in a cohort of 65 year old men screened in the Swedish general population based AAA screening program, with the aim of exploring the effectiveness of hypothetical targeted screening strategies.

Methods: All men attending AAA screening in four neighbouring counties in Sweden between 2006 and 2010 completed a health questionnaire on smoking habits and medical history. Abdominal aortic aneurysm was defined as measuring ≥ 30 mm. The sensitivity and specificity of different targeted screening strategies, with targeted subpopulations defined by duration of smoking with and without additional risk factors, were explored using receiver operating characteristic (ROC) curves.

Results: A total of 16 232 men were screened, with 236 (1.5%) screening detected AAAs. A strategy combining smoking, presence of coronary artery disease (CAD), or both was associated with the mathematically optimal balance between sensitivity and specificity (optimal threshold) in the ROC analysis. The optimal threshold corresponded to targeting men having smoked for thirty years or more, a history of CAD, or both, where 74.0% of all AAAs could be detected by screening 33.0% of the population, compared with general screening. Targeting men that have smoked for ten years or more indicated that 84.0% of all AAAs could be detected by screening 55.0% of the population. A simplified strategy of targeting ever smokers resulted in detecting 85.0% of all AAAs by screening 61.0% of the population.

Conclusion: Targeted screening of men at high risk of AAA, focusing on smoking history for inclusion, may be a safe and effective alternative to general population screening.