title: Epidemiology of ruptured abdominal aortic aneurysms in a well-defined Norwegian population with trends in incidence, intervention rate, and mortality.
abstract: OBJECTIVE
  Ruptured infrarenal abdominal aortic aneurysms (rAAAs) represent both a life-threatening emergency for the affected patient and a considerable health burden globally. The aim of this study was to investigate the contemporary epidemiology of rAAA in a defined Norwegian population for which both hospital and autopsy data were available.
  
  
  METHODS
  This was a retrospective, single-center population-based study of rAAA. The study includes all consecutively diagnosed prehospital and in-hospital cases of rAAA in the catchment area of Stavanger University Hospital between January 2000 and December 2012. Incidence and mortality rates (crude and adjusted) were calculated using national demographic data.
  
  
  RESULTS
  A total of 216 patients with primary rAAA were identified. The adjusted incidence rate for the study period was 11.0 per 100,000 per year (95% confidence interval [CI], 9.6-12.5). Twenty patients died out of the hospital, and 144 of the 196 patients (73%) admitted to the hospital underwent surgery. The intervention rate varied from 48% to 81% during the study period. The adjusted mortality rate was 7.5 per 100,000 per year (95% CI, 6.3-8.8). No differences in the incidence and mortality rates were found in comparing early and late periods. The 90-day standardized mortality ratio for the study period was 37.2 (95% CI, 31.6-43.7). The overall 90-day mortality was 68% (146 of 216 persons) and 51% (74 of 144 persons) for the patients treated for rAAA.
  
  
  CONCLUSIONS
  We found a stable incidence and mortality rate during a decade. The prehospital death rate was lower (9%), the intervention rate (73%) higher, and the total mortality (68%) lower than in most other studies. Geographic and regional differences may influence the epidemiologic description of rAAA and hence should be taken into consideration in comparing outcomes for in-hospital mortality and intervention rates.
authors: Vascular Surgery Unit, Stavanger University Hospital, Stavanger, Norway.
authors: Andreas
authors: A
authors: Reite
authors: Department of Gastrointestinal Surgery, Stavanger University Hospital, Stavanger, Norway; Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors: Kjetil
authors: K
authors: Søreide
authors: Department of Pathology, Stavanger University Hospital, Stavanger, Norway; Department of Health Registries, Norwegian Institute of Public Health, Oslo, Norway.
authors: Christian Lycke
authors: CL
authors: Ellingsen
authors: Research Department, Stavanger University Hospital, Stavanger, Norway; Department of Mathematics and Natural Science, University of Stavanger, Stavanger, Norway.
authors: Jan Terje
authors: JT
authors: Kvaløy
authors: Vascular Surgery Unit, Stavanger University Hospital, Stavanger, Norway. Electronic address: vemo@sus.no.
authors: Morten
authors: M
authors: Vetrhus
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000401:mortality* / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000401:mortality* / Q000601:surgery*; D003431:Cross-Cultural Comparison; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009664:Norway; D011183:Postoperative Complications / Q000401:mortality; D012189:Retrospective Studies; D016019:Survival Analysis