title: The effect of prognostic data presentation format on perceived risk among surrogate decision makers of critically ill patients: a randomized comparative trial.
abstract: OBJECTIVE
  The purpose of this study is to determine whether varying the format used to present prognostic data alters the perception of risk among surrogate decision makers in the intensive care unit (ICU).
  
  
  METHODS
  This was a prospective randomized comparative trial conducted in a 23-bed adult tertiary ICU. Enrolled surrogate decision makers were randomized to 1 of 2 questionnaires, which presented hypothetical ICU scenarios, identical other than the format in which prognostic data were presented (eg, frequencies vs percentages). Participants were asked to rate the risk associated with each prognostic statement.
  
  
  RESULTS
  We enrolled 141 surrogate decision makers. The perception of risk varied significantly dependent on the presentation format. For "quantitative data," risks were consistently perceived as higher, when presented as frequencies (eg, 1 in 50) compared with equivalent percentages (eg, 2%). Framing "qualitative data" in terms of chance of "death" rather than "survival" led to a statistically significant increase in perceived risks. Framing "quantitative" data in this way did not significantly affect risk perception.
  
  
  CONCLUSIONS
  Data format had a significant effect on how surrogate decision makers interpreted risk. Qualitative statements are interpreted widely and affected by framing. Where possible, multiple quantitative formats should be used for presenting prognostic information.
authors.affiliation: Department of Intensive Care Medicine, Royal Perth Hospital, Perth, 6000, Western Australia. Electronic address: Drandychapman@gmail.com.
authors.forename: Andy R
authors.initials: AR
authors.lastname: Chapman
authors.affiliation: Department of Intensive Care Medicine, Royal Perth Hospital, Perth, 6000, Western Australia; School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia.
authors.forename: Edward
authors.initials: E
authors.lastname: Litton
authors.affiliation: Department of Intensive Care Medicine, Royal Perth Hospital, Perth, 6000, Western Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Chamberlain
authors.affiliation: Department of Intensive Care Medicine, Royal Perth Hospital, Perth, 6000, Western Australia; School of Population Health, University of Western Australia, Perth, Western Australia.
authors.forename: Kwok M
authors.initials: KM
authors.lastname: Ho
mesh_terms: D000328:Adult; D003142:Communication; D003422:Critical Care; D016638:Critical Illness; D003657:Decision Making; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment
keywords: Communication; Decision making; Intensive care; Probability; Prognosis; Risk