title: Mortality rates for patients with acute lung injury/ARDS have decreased over time.
abstract: BACKGROUND
  Over the last decade, several studies have suggested that survival rates for patients with acute lung injury (ALI) or ARDS may have improved. We performed a systematic analysis of the ALI/ARDS literature to document possible trends in mortality between 1994 and 2006.
  
  
  METHODS
  We used the Medline database to select studies with the key words "acute lung injury," "ARDS," "acute respiratory failure," and "mechanical ventilation." All studies that reported mortality rates for patients with ALI/ARDS defined according to the criteria of the American European Consensus Conference were selected. We excluded studies with < 30 patients and studies limited to specific subgroups of ARDS patients such as sepsis, trauma, burns, or transfusion-related ARDS.
  
  
  RESULTS
  Seventy-two studies were included in the analysis. There was a wide variation in mortality rates among the studies (15 to 72%). The overall pooled mortality rate for all studies was 43% (95% confidence interval, 40 to 46%). Metaregression analysis suggested a significant decrease in overall mortality rates of approximately 1.1%/yr over the period analyzed (1994 to 2006). The mortality reduction was also observed for hospital but not for ICU or 28-day mortality rates.
  
  
  CONCLUSIONS
  In this literature review, the data are consistent with a reduction in mortality rates in general populations of patients with ALI/ARDS over the last 10 years.
authors.affiliation: Department of Intensive Care, Erasme Hospital, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Massimo
authors.initials: M
authors.lastname: Zambon
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
mesh_terms: D014943:Global Health; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D012128:Respiratory Distress Syndrome / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends