A Comparison Between the Short Term and Long Term Benefits of Screening for Abdominal Aortic Aneurysms from the Huntingdon Aneurysm Screening Programme

Abstract

Background The UK Multicentre Aneurysm Screening Study (MASS) showed a 44% reduction in AAA-related mortality after 4 years and predicted an increased number of deaths prevented in the longer term. We aim to compare the 5 and 13 years benefit from aneurysm screening in the Huntingdon Aneurysm screening programme. Methods Incidence and mortality of ruptured AAA (RAAA) after 5 and 13 years of screening in a population based aneurysm screening program. Results Five years of screening resulted in a reduction in the incidence of RAAA of 49% (95% CI: 3–74%). Nine out of 11 ruptures in the invited group did not survive (mortality 82%; 95% CI: 48–98%) compared to 38 non-survivors from 51 ruptures in the control group (mortality 75%; 95% CI: 60–86%). Five years of screening resulted in an RAAA-related mortality reduction of 45% (95% CI: −15 to 74%). After 13 years of screening the incidence of RAAA was reduced by 73% (95% CI: 58–82%). Twenty-one out of 29 ruptures in the invited group did not survive (mortality 72%; 95% CI: 53–87%) compared to 64 non-survivors from 82 ruptures in the control group (mortality 78%; 95% CI: 68–86%). Thirteen years screening resulted in a reduction of mortality from RAAA of 75% (95% CI: 58–84%). The number needed to screen to prevent one death reduced from 1380 after 5 years to 505 after 13 years. The number of elective AAA operations needed to prevent one death reduced from 6 after 5 years to 4 after 13 years. Conclusion AAA screening becomes increasingly beneficial as screening continues over the longer term. Benefits continue to increase after screening has ceased.