title: Studying outcomes of intensive care unit survivors: the role of the cohort study.
abstract: BACKGROUND
  As research focuses on long-term patient outcomes and the "real world" effectiveness of intensive care unit (ICU) therapies, the cohort study is increasingly being used in critical care research.
  
  
  METHODS
  Using examples of prior cohort studies in intensive care, we review the key elements of this research design and evaluate its advantages and limitations for critical care research. Furthermore, through a systematic search of the literature we summarize data from 70 prior published cohort studies of medium- and long-term outcomes in adult critical care medicine.
  
  
  CONCLUSIONS
  This research demonstrates that the prospective cohort study is a powerful research design that has not been fully leveraged to assess relationships between exposures and long-term outcomes of ICU survivors.
  
  
  CONCLUSIONS
  We make recommendations for the design of future cohort studies to maximize the impact of this research in improving the long-term outcomes of critically ill patients.
authors.affiliation: School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Dowdy
authors.forename: Dale M
authors.initials: DM
authors.lastname: Needham
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Mendez-Tellez
authors.forename: Margaret S
authors.initials: MS
authors.lastname: Herridge
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Pronovost
mesh_terms: D015331:Cohort Studies; D003422:Critical Care; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D017741:Survivors / Q000706:statistics & numerical data*