title: The influence of physician explanations on patient preferences about future health-care states.
abstract: OBJECTIVE
  To determine the influence of alternative explanations by physicians of the purpose of a medical intervention (intubation and ventilatory support, IVS) on three types of patient preferences: desire for IVS, the length of time patients would find IVS acceptable, and the minimum probability of a good medical outcome patients would require before assenting to continued support with IVS.
  
  
  METHODS
  Structured interviews were conducted with patients followed in a continuity care general medicine clinic at the Department of Veterans Affairs Medical Center, Portland, Oregon. Patients were asked to consider whether they would accept IVS at a future time. Patients were randomly assigned to one of two explanation conditions that differed in terms of their future medical contexts, that is, the degrees of specification of the nature of the medical condition patients were asked to consider. The general-explanation group was asked to consider the future medical context of " an unspecified medical condition"; the specific-explanation group was asked to consider the future medical context of "a severe pneumonia." Patients were asked three questions: 1) Would you accept IVS (yes or no)? 2) How long would you allow your physician to continue IVS?; and 3) After being on IVS for 2-3 days, what would be the minimum chance of recovery from the condition you would require before agreeing to continued IVS? "Chance of recovery" was defined for both groups as the probability that the patient would be able to leave the hospital and be able to take care of activities of daily living unassisted with minimal change in his or her mental state from the pre-hospitalization status.
  
  
  RESULTS
  Of 186 patients (mean age = 66.5 years; mean education = 12.7 years), 97 received the general explanation and 89 received the specific explanation about a severe pneumonia. Significantly fewer (p = 0.03) patients receiving the general explanation wanted physicians to intervene with IVS (general 94% vs specific 100%). Patients receiving the general explanation were willing to accept significantly fewer (p = 0.009) days of intubation (general 65 days vs specific 96 days). Significantly fewer (p < 0.0001) patients receiving the general explanation wanted physicians to continue IVS when the probability of a successful outcome was less than 50% (general 30% vs specific 64%).
  
  
  CONCLUSIONS
  Physician explanations--based on general (unspecified medical condition) vs specific (severe pneumonia) explanations--have a marked influence on the duration of IVS patients would permit and the probability of a good outcome required to continue IVS.
authors.affiliation: Department of Veterans Affairs Medical Center, Portland, Oregon 97201, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Mazur
authors.forename: D H
authors.initials: DH
authors.lastname: Hickam
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000368:Aged; D003657:Decision Making; D005260:Female; D006801:Humans; D008020:Life Support Care / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D010353:Patient Education as Topic; D010358:Patient Participation; D011379:Prognosis; D012121:Respiration, Artificial / Q000523:psychology*