title: The Impact of Patient Participation in Health Decisions Within Medical Encounters: A Systematic Review.
abstract: Although there are compelling moral arguments for patient participation in medical decisions, the link to health outcomes has not been systematically explored.
  
  
  
  Assess the extent to which patient participation in decision making within medical encounters is associated with measured patient outcomes.
  
  
  
  We conducted a primary search in PubMed-excluding non-English and animal studies-for articles on decision making in the context of the physician-patient relationship published through the end of February 2015, using the MeSH headings (Physician-Patient Relations [MeSH] OR Patient Participation [MeSH]) and the terms (decision OR decisions OR option OR options OR choice OR choices OR alternative OR alternatives) in the title or abstract. We also conducted a secondary search of references in all articles that met the inclusion criteria.
  
  
  
  A thorough search process yielded 116 articles for final analysis. There was wide variation in study design, as well as measurement of patient participation and outcomes, among the studies. Eleven of the 116 studies were randomized controlled trials (RCTs). Interventions increased patient involvement in 10 (91%) of the 11 RCTs. At least one positive outcome was detected in 5 (50%) of the 10 RCTs reporting increased participation; the ratio of positive results among all outcome variables measured in these studies was much smaller. Although proportions differed, similar patterns were found across the 105 nonrandomized studies.
  
  
  
  Very few RCTs in the field have measures of participation in decision making and at least one health outcome. Moreover, extant studies exhibit little consistency in measurement of these variables, and results are mixed. There is a great need for well-designed, reproducible research on clinically relevant outcomes of patient participation in medical decisions.
authors.affiliation: American Institutes for Research (MLC)
authors.forename: Marla L
authors.initials: ML
authors.lastname: Clayman
authors.affiliation: Hamad Medical Corporation/Weill Cornell Medical College-Qatar (CB)
authors.forename: Carma L
authors.initials: CL
authors.lastname: Bylund
authors.affiliation: School of Pharmacy, University of Wisconsin-Madison, WI, USA (BC)
authors.forename: Betty
authors.initials: B
authors.lastname: Chewning
authors.affiliation: Connecticut Institute for Primary Care Innovation (GM)|Department of Medicine, University of Connecticut School of Medicine, Hartford, CT, USA (GM)|PatientWisdom (GM)
authors.forename: Gregory
authors.initials: G
authors.lastname: Makoul
mesh_terms: D002755:Choice Behavior; D000066491:Clinical Decision-Making; D006801:Humans; D010358:Patient Participation / Q000706:statistics & numerical data*; D010817:Physician-Patient Relations; D016896:Treatment Outcome
keywords: measurement; outcomes; patient engagement; patient participation; physician-patient communication; shared decision making