The impact of decreasing abdominal aortic aneurysm prevalence on a local aneurysm screening programme.

Abstract

The NHS Abdominal Aortic Aneurysm Screening Programme (NAAASP), based on the Multicentre Aneurysm Screening Study (MASS) trial (2002), is being introduced across the UK. Recent studies have demonstrated a decline in prevalence of abdominal aortic aneurysm (AAA). The aim of this study was to examine the effect of this on screening workload. A model was developed to predict screening and surgical workload for a screening centre (Bristol - population 1,123,203). Workload was compared using data from MASS with data from the "Early Implementers" (EI) of NAAASP. Modelling for 2011/2012 using EI data predicted significantly fewer men diagnosed with an AAA compared to MASS data [84 (EI) versus 198 (MASS) p < 0.0001] and fewer referrals to a vascular surgeon for AAA repair [10 (EI) versus 30 (MASS) p = 0.0002). This difference became more marked with time (2015/16: 90 (EI) versus 212 (MASS) men diagnosed with an AAA (p < 0.0001) and 29 (EI) versus 71 (MASS) referred to a vascular surgeon (p < 0.0001)). From 2015/16 there was also a significant reduction in the predicted number of ultrasound scans. Modelling screening activity based on contemporary epidemiological data demonstrates a significant reduction in workload compared to MASS data. This has implications for workforce planning, the introduction of new screening centres and the future of NAAASP.