title: Practice based evidence: incorporating clinical heterogeneity and patient-reported outcomes for comparative effectiveness research.
abstract: BACKGROUND
  Comparative effectiveness research analyzes groups of patients and looks for associations between medical treatments and patient outcomes. To make meaningful comparisons of medical interventions, one must consider clinical heterogeneity of patient populations, intervention combinations, and outcomes.
  
  
  OBJECTIVE
  To explain how practice-based evidence (PBE) study methodology measures and controls for heterogeneity of patients, treatments, and outcomes seen in real-world clinical settings.
  
  
  METHODS
  Overview of PBE methodology.
  
  
  CONCLUSIONS
  PBE study designs address comparative effectiveness by creating a comprehensive set of patient, treatment, and outcome variables, and analyzing them to identify treatments associated with better outcomes for specific types of patients. PBE studies are an alternative to randomized controlled trials, well suited to determine what works best for specific patient types, and provide clinicians with a rational basis for treatment recommendations for individual patients. They provide a holistic picture of patients, treatments, and outcomes, with no preset limits to the number of variables that can be included. Such an approach is needed for high quality comparative effectiveness research.
authors.affiliation: International Severity Information Systems, Inc, Institute for Clinical Outcomes Research, Salt Lake City, UT 84102, USA. shorn@isisicor.com
authors.forename: Susan D
authors.initials: SD
authors.lastname: Horn
authors.forename: Julie
authors.initials: J
authors.lastname: Gassaway
mesh_terms: D000367:Age Factors; D055812:Community-Based Participatory Research / Q000458:organization & administration; D057186:Comparative Effectiveness Research / Q000458:organization & administration*; D015986:Confounding Factors, Epidemiologic; D003627:Data Interpretation, Statistical; D019317:Evidence-Based Medicine; D006801:Humans; D011446:Prospective Studies; D012720:Severity of Illness Index; D012737:Sex Factors; D012959:Socioeconomic Factors; D016896:Treatment Outcome