title: Propensity scores: Methods, considerations, and applications in the Journal of Thoracic and Cardiovascular Surgery.
abstract: OBJECTIVE
  To review the published literature using propensity scoring, describe shortcomings in the use of this technique, and provide conceptual background for understanding and correctly implementing studies that use propensity matching.
  
  
  METHODS
  We survey the published statistical literature and make recommendations for a set of standard criteria for studies that use propensity matching. We evaluated adherence to these criteria in recent publications in the Journal of Thoracic and Cardiovascular Surgery and determined how well the standards were applied.
  
  
  RESULTS
  We found that studies that use propensity matching are rarely documented well enough to be convincing in their results. When documentation is available, statistical shortcomings are common.
  
  
  CONCLUSIONS
  Improved statistical practice is needed when using propensity scoring. This article suggests standard criteria for using this method in Journal publications.
authors.affiliation: Department of Public Heath Sciences, University of Virginia, Charlottesville, Va.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: McMurry
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, University of Virginia Health System, Charlottesville, Va.
authors.forename: Yinin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Thoracic and Cardiovascular Surgery and Department of Quantitative Health Sciences, Research Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.affiliation: Department of Public Heath Sciences, University of Virginia, Charlottesville, Va; Division of Thoracic Surgery, Department of Surgery, University of Virginia Health System, Charlottesville, Va. Electronic address: bdk8g@virginia.edu.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Kozower
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D010506:Periodicals as Topic; D057216:Propensity Score; D013903:Thoracic Surgery
keywords: causal inference; matching; observational studies; propensity score; statistical methods