title: Measuring patient tolerance for future adverse events in low-risk emergency department chest pain patients.
abstract: OBJECTIVE
  We assess emergency department (ED) patients' risk thresholds for preferring admission versus discharge when presenting with chest pain and determine how the method of information presentation affects patients' choices.
  
  
  METHODS
  In this cross-sectional survey, we enrolled a convenience sample of lower-risk acute chest pain patients from an urban ED. We presented patients with a hypothetical value for the risk of adverse outcome that could be decreased by hospitalization and asked them to identify the risk threshold at which they preferred admission versus discharge. We randomized patients to a method of numeric presentation (natural frequency or percentage) and the initial risk presented (low or high) and followed each numeric assessment with an assessment based on visually depicted risks.
  
  
  RESULTS
  We enrolled 246 patients and analyzed data on 234 with complete information. The geometric mean risk threshold with numeric presentation was 1 in 736 (1 in 233 with a percentage presentation; 1 in 2,425 with a natural frequency presentation) and 1 in 490 with a visual presentation. Fifty-nine percent of patients (137/234) chose the lowest or highest risk values offered. One hundred fourteen patients chose different thresholds for numeric and visual risk presentations. We observed strong anchoring effects; patients starting with the lowest risk chose a lower threshold than those starting with the highest risk possible and vice versa.
  
  
  CONCLUSIONS
  Using an expected utility model to measure patients' risk thresholds does not seem to work, either to find a stable risk preference within individuals or in groups. Further work in measurement of patients' risk tolerance or methods of shared decisionmaking not dependent on assessment of risk tolerance is needed.
authors: Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance, CA. Electronic address: jennifer@emedharbor.edu.
authors: Jennifer C
authors: JC
authors: Chen
authors: UCLA Emergency Medicine Center, University of California, Los Angeles, CA.
authors: Richelle J
authors: RJ
authors: Cooper
authors: UCLA Emergency Medicine Center, University of California, Los Angeles, CA.
authors: Ana
authors: A
authors: Lopez-O'Sullivan
authors: UCLA Emergency Medicine Center, University of California, Los Angeles, CA.
authors: David L
authors: DL
authors: Schriger
mesh_terms: D000368:Aged; D002637:Chest Pain / Q000523:psychology* / Q000628:therapy; D003430:Cross-Sectional Studies; D003657:Decision Making; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data; D057240:Patient Preference / Q000523:psychology / Q000706:statistics & numerical data*; D018570:Risk Assessment