Patient or Physician Preferences for Decision Analysis

The choice between amniocentesis and chononic villus sampling for prenatal genetic testing involves tradeoffs of the benefits and risks of the tests. Decision analysis is a method of explicitly weighing such tradeoffs. The authors examined the relationship between prenatal test choices made by patients and the choices prescribed by deci sion-analytic models based on their preferences, and separate models based on the preferences of their physicians. Preferences were assessed using written scenarios describing prenatal testing outcomes, and were recorded on linear rating scales. After adjustment for sociodemographic and obstetric confounders, test choice was signifi cantly associated with the choice of decision models based on patient preferences (odds ratio 4.44; CI, 2.53 to 7.78), but not with the choice of models based on the preferences of the physicians (odds ratio 1.60; CI, 0.79 to 3.26). Agreement between decision analyses based on patient preferences and on physician preferences was little better than chance (kappa = 0.085 ± 0.063). These results were robust both to changes in the decision-analytic probabilities and to changes in the model structure itself to simulate non-expected utility decision rules. The authors conclude that patient but not physician preferences, incorporated in decision models, correspond to the choice of amniocentesis or chorionic villus sampling made by the patient. Nevertheless, because patient preferences were assessed after referral for genetic testing, prospec tive preference-assessment studies will be necessary to confirm this association. Key words: decision analysis; patient preferences; physician preferences; prenatal genetic testing. (Med Decis Making 1999;19:66-77)