title: Growth rates of small abdominal aortic aneurysms correlate with clinical events.
abstract: BACKGROUND
  This retrospective analysis of prospectively collected abdominal aortic aneurysm (AAA) screening data aimed to identify predictors of AAA-related events (surgery or death) with a view to better targeting of screening.
  
  
  METHODS
  For the interval 1984-2007, data for 1649 subjects with an AAA were collected prospectively as part of the Chichester AAA screening programme. This included serial aortic size measurements, blood pressure, risk factors for arterial disease and concurrent medications. AAA growth rates were adjusted for risk factor confounders using flexible hierarchical modelling. AAA growth distribution was analysed using Silverman's test of multimodality.
  
  
  RESULTS
  Some 1231 subjects met the inclusion criteria of having more than one scan and a surveillance interval of over 3 months. AAA growth showed a bimodal pattern with nearly 50 per cent of all aneurysms never progressing to surgery or rupture. Adjusted annual AAA growth rates of at least 2 mm significantly predicted AAA-related events.
  
  
  CONCLUSIONS
  This analysis identified a bimodal growth pattern for AAA, with a significant association between annual AAA growth rate of at least 2 mm and AAA-related events.
authors.affiliation: Department of Vascular Surgery, Western Sussex Hospital NHS Trust, Chichester, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Thompson
authors.forename: J A
authors.initials: JA
authors.lastname: Cooper
authors.forename: H A
authors.initials: HA
authors.lastname: Ashton
authors.forename: H
authors.initials: H
authors.lastname: Hafez
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors