title: The influence of screening on the incidence of ruptured abdominal aortic aneurysms.
abstract: OBJECTIVE
  The purpose of this study was to estimate the influence of a screening program on the incidence and mortality of ruptured abdominal aortic aneurysms (RAAAs).
  
  
  METHODS
  The effects of screening on the incidence and death rate of RAAAs were investigated with a stepped wedge study design. RAAAs that occurred in the Huntingdon district were traced with an examination of all hospital records and community postmortem records.
  
  
  RESULTS
  During the 5-year period from 1991 to 1996, 78 RAAAs occurred in the Huntingdon district: 62 in men and 16 in women. Eleven of the 62 men with RAAAs had been invited for screening. The incidence of RAAA in the invited group was 3.7 per 10,000 person-years (py; 95% confidence interval [CI], 1.5 - 7.3). In the noninvited group, the incidence was 7.3 per 10,000 py (95% CI, 5.3. - 9.2), a rate ratio of 0.51 (95% CI, 0.26 - 0.97). The mortality of rAAAs in the invited group was 3.0 per 10, 000 py (95% CI, 1.4 - 5.4) as compared with 5.4 per 10,000 py in the noninvited group (95% CI, 3.9 - 7.3), resulting in a rate ratio of 0. 55 (95% CI, 0.26 - 1.15).
  
  
  CONCLUSIONS
  Screening for asymptomatic AAAs can reduce the incidence rate of RAAAs by 49% (95% CI, 3% - 74%).
authors.affiliation: Institute of Public Halth, University of Cambridge, Department of Surgery, Cambridge, CB2 2SR, United Kingdom.
authors.forename: T B
authors.initials: TB
authors.lastname: Wilmink
authors.forename: C R
authors.initials: CR
authors.lastname: Quick
authors.forename: C S
authors.initials: CS
authors.lastname: Hubbard
authors.forename: N E
authors.initials: NE
authors.lastname: Day
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D005194:Family Practice; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015995:Prevalence; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology