title: Late results concerning feasibility and compliance from a randomized trial of ultrasonographic screening for abdominal aortic aneurysm.
abstract: BACKGROUND
  The study was an update at 10 years of a randomized trial of the efficacy of screening for abdominal aortic aneurysm (AAA). The extent of benefit, feasibility and compliance were examined, and reasons why this intervention may fail a proportion of those screened were identified.
  
  
  METHODS
  A total of 6058 men aged 65 years and over were randomized to a group invited to attend ultrasonographic screening or to a control group. The mortality rate from AAA in the two arms of the trial was compared using a Poisson model. Analyses were by intention to treat.
  
  
  RESULTS
  There was a 21 per cent reduction in mortality rate from AAA over the 10-year follow-up (relative risk 0.79 (95 per cent confidence interval 0.53 to 1.40)). The observed relative mortality reduction peaked at 4 years with a 52 per cent reduction in the study group. Eighteen of 24 AAA deaths in the study group were among those who did not attend the first screen, or failed to comply with the follow-up protocol.
  
  
  CONCLUSIONS
  A greater awareness of the benefits of full participation in a screening programme could provide a larger and sustained mortality reduction.
authors.affiliation: Medical Research Council Biostatistics Unit, Institute of Public Health and Strangeways Research Laboratory, Cambridge, UK.
authors.forename: K A
authors.initials: KA
authors.lastname: Vardulaki
authors.forename: N M
authors.initials: NM
authors.lastname: Walker
authors.forename: E
authors.initials: E
authors.lastname: Couto
authors.forename: N E
authors.initials: NE
authors.lastname: Day
authors.forename: S G
authors.initials: SG
authors.lastname: Thompson
authors.forename: H A
authors.initials: HA
authors.lastname: Ashton
authors.forename: R A P
authors.initials: RA
authors.lastname: Scott
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D010349:Patient Compliance; D016019:Survival Analysis; D016896:Treatment Outcome; D014463:Ultrasonography