title: Reconsidering healthcare evidence as dynamic and distributed: the role of information and cognition.
abstract: OBJECTIVE
  The basic thrust of evidence-based healthcare is that current best evidence should be used explicitly and judiciously for diagnosis, management, and other activities in healthcare settings. For this to be possible, researchers, practitioners, and other stakeholders must have a clear and accurate conceptualization of what constitutes 'evidence' in healthcare environments, and the manner in which it is used in decision-making and other activities. Currently, the dominant conceptualization of evidence is that of a body of information that can be retrieved by stakeholders for use in healthcare practice. The aim of this article is to critically examine the concept of evidence, particularly in light of recent models of human cognition and information use in decision-making and other cognitive activities.
  
  
  METHODS
  In this theoretical article, we employ both analytical and synthetic methods to critically examine the concepts under investigation. Key concepts, such as evidence and information, and the essential relationships between them are analyzed from the vantage point of cognitive science, information science, and other relevant disciplines to explicate a conceptualization of evidence that moves past static and objectivist accounts.
  
  
  RESULTS
  We demonstrate that evidence is fundamentally information that takes various forms-i.e., artifacts, mental structures, or communication processes. Specific forms and manifestations of evidence can thus be described in the context of information use in dynamic information environments. Furthermore, evidence-based healthcare activities are shown to be fundamentally cognitive in nature. For any given evidence-based healthcare activity, its quality and outcome can be understood in the context of how different sources of evidence are coordinated within a distributed cognitive system. In this sense, evidence based health care activity becomes more a matter of understanding the movement of information and knowledge within a distributed and dynamic cognitive system than mere access to or translation of a ready-at-hand resource.
  
  
  CONCLUSIONS
  The conceptualization of evidence presented in this article has a number of implications for evidence-based healthcare-in terms of where attention is focused, the direction of future research efforts, how evidence generation, use, and practice are conceptualized and discussed, and how healthcare technologies are designed and evaluated. Furthermore, the conceptualization presented in this article has implications for the manner in which evidence 'hierarchies' are developed. Such hierarchies do not provide a complete picture of evidence and the way it is used in healthcare activities. Understanding the dynamic nature of evidence and its role in distributed cognitive activities may lead to more robust and multi-faceted taxonomies, frameworks, and hierarchies related to evidence-based healthcare.
authors.affiliation: Insight Lab, Western University, London, ON, Canada.
authors.forename: Kamran
authors.initials: K
authors.lastname: Sedig
authors.forename: Paul
authors.initials: P
authors.lastname: Parsons
authors.forename: Anthony
authors.initials: A
authors.lastname: Naimi
authors.forename: Keith
authors.initials: K
authors.lastname: Willoughby
mesh_terms: D003071:Cognition; D003142:Communication; D003657:Decision Making; D003695:Delivery of Health Care / Q000458:organization & administration*; D019317:Evidence-Based Medicine / Q000458:organization & administration*; D006801:Humans; D033181:Information Dissemination; D019359:Knowledge