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

BackgroundThe 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.MethodsIncidence and mortality of ruptured AAA (RAAA) after 5 and 13 years of screening in a population based aneurysm screening program.ResultsFive 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.ConclusionAAA screening becomes increasingly beneficial as screening continues over the longer term. Benefits continue to increase after screening has ceased.