title: Eight-year trend of acute respiratory distress syndrome: a population-based study in Olmsted County, Minnesota.
abstract: BACKGROUND
  significant progress has been made in understanding the pathogenesis of acute respiratory distress syndrome (ARDS). Recent advances in hospital practice may have reduced the incidence of this lethal syndrome.
  
  
  OBJECTIVE
  to observe incidence trends and associated outcomes of ARDS.
  
  
  METHODS
  this population-based cohort study was conducted in Olmsted County, Minnesota. Using a validated screening protocol, investigators identified intensive care patients with acute hypoxemia and bilateral pulmonary infiltrates. The presence of ARDS was independently confirmed according to American-European Consensus Conference criteria. The incidence of ARDS and associated outcomes were compared over the 8-year study period (2001-2008).
  
  
  RESULTS
  over the 8-year period, critically ill Olmsted County residents presented with increasing severity of acute illness, a greater number of comorbidities, and a higher prevalence of major predisposing conditions for ARDS. The ARDS incidence decreased significantly from 82.4 to 38.9 per 100,000 person-years during the study period (P < 0.001). A decline in hospital-acquired ARDS (P < 0.001) was responsible for the fall in the incidence density with no change on admission (P = 0.877). Overall, mortality and hospital and intensive care unit lengths of stay decreased over time (P < 0.001), whereas the ARDS case-fatality did not change significantly.
  
  
  CONCLUSIONS
  despite an increase in patients' severity of illness, number of comorbidities, and prevalence of major ARDS risk factors, the incidence of ARDS in this suburban community decreased by more than half. Correlation of the observed findings with changes in health care delivery may have important implications for the planning of acute care services in other regions.
authors.affiliation: Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. gajic.ognjen@mayo.edu
authors.forename: Guangxi
authors.initials: G
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Malinchoc
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cartin-Ceba
authors.forename: Chakradhar V
authors.initials: CV
authors.lastname: Venkata
authors.forename: Daryl J
authors.initials: DJ
authors.lastname: Kor
authors.forename: Steve G
authors.initials: SG
authors.lastname: Peters
authors.forename: Rolf D
authors.initials: RD
authors.lastname: Hubmayr
authors.forename: Ognjen
authors.initials: O
authors.lastname: Gajic
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D009017:Morbidity / Q000639:trends; D011159:Population Surveillance; D012128:Respiratory Distress Syndrome / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors