title: Recommendations for screening intervals for small aortic aneurysms.
abstract: BACKGROUND
  The aim was to determine the optimum rescreening interval for small abdominal aortic aneurysms (AAAs).
  
  
  METHODS
  Data from 12 years of population screening of 65-year-old men were analysed and 1121 small AAAs (less than 4.0 cm in initial diameter) were divided into groups: group 1 (2.6-2.9 cm; n = 625), group 2 (3.0-3.4 cm; n = 330) and group 3 (3.5-3.9 cm; n = 166). Expansion rate and the cumulative proportions to expand to over 5.5 cm, or require surgery, or rupture were calculated.
  
  
  RESULTS
  Expansion rate was related to initial aortic diameter: 0.09 cm per year in group 1, 0.16 cm per year in group 2 and 0.32 cm per year in group 3 (P < 0.001). Aneurysms in 2.4 per cent of patients in group 1 exceeded a diameter of 5.5 cm or required surgery within 5 years; there were no ruptures. In group 2, no aorta exceeded 5.5 cm but at 3 years 2.1 per cent had reached 5.5 cm and 2.9 per cent had required surgery. The rupture rate at 3 years was zero. In group 3, the aneurysm diameter exceeded 5.5 cm in 1.2 per cent of patients, but no patient required surgery or experienced rupture within 1 year; at 2 years 10.5 per cent of aneurysms had exceeded 5.5 cm in diameter or required surgery and 1.4 per cent had ruptured.
  
  
  CONCLUSIONS
  The appropriate rescreening interval can be determined by initial aortic diameter in screened 65-year-old men. AAAs of initial diameter 2.6-2.9 cm should be rescanned at 5 years, those of 3.0-3.4 cm at 3 years and those of 3.5-3.9 cm at 1 year.
authors.affiliation: Department of Vascular Surgery, Gloucestershire Royal Hospital, Gloucester, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: McCarthy
authors.forename: E
authors.initials: E
authors.lastname: Shaw
authors.forename: M R
authors.initials: MR
authors.lastname: Whyman
authors.forename: J J
authors.initials: JJ
authors.lastname: Earnshaw
authors.forename: K R
authors.initials: KR
authors.lastname: Poskitt
authors.forename: B P
authors.initials: BP
authors.lastname: Heather
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000401:mortality / Q000473:pathology / Q000517:prevention & control*; D001019:Aortic Rupture / Q000401:mortality / Q000473:pathology; D002423:Cause of Death; D004739:England / Q000453:epidemiology; D006287:Health Planning Guidelines; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D011379:Prognosis; D016019:Survival Analysis