title: Outcomes research in the development and evaluation of practice guidelines.
abstract: BACKGROUND
  Practice guidelines have been developed in response to the observation that variations exist in clinical medicine that are not related to variations in the clinical presentation and severity of the disease. Despite their widespread use, however, practice guideline evaluation lacks a rigorous scientific methodology to support its development and application.
  
  
  CONCLUSIONS
  Firstly, we review the major epidemiological foundations of practice guideline development. Secondly, we propose a chronic disease epidemiological model in which practice patterns are viewed as the exposure and outcomes of interest such as quality or cost are viewed as the disease. Sources of selection, information, confounding and temporal trend bias are identified and discussed.
  
  
  CONCLUSIONS
  The proposed methodological framework for outcomes research to evaluate practice guidelines reflects the selection, information and confounding biases inherent in its observational nature which must be accounted for in both the design and the analysis phases of any outcomes research study.
authors.affiliation: Division of Clinical Epidemiology, Research Institute of the McGill University Health Center, Montreal, Canada. louise.pilote@mcgill.ca
authors.forename: Louise
authors.initials: L
authors.lastname: Pilote
authors.forename: Ira B
authors.initials: IB
authors.lastname: Tager
mesh_terms: D035843:Biomedical Research; D002908:Chronic Disease / Q000453:epidemiology* / Q000628:therapy; D015986:Confounding Factors, Epidemiologic; D003625:Data Collection; D019992:Databases as Topic; D004812:Epidemiologic Methods; D005069:Evaluation Studies as Topic; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000379:methods*; D017410:Practice Guidelines as Topic / Q000592:standards*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D015983:Selection Bias; D016896:Treatment Outcome; D035501:Uncertainty