THE ACCURACY OF SUBSTITUTED JUDGMENTS IN PATIENTS WITH TERMINAL DIAGNOSES

Background: Patients' loved ones often make end-of-life treatment deci sions, but the accuracy of their substituted judgments and the factors associated with accuracy are poorly understood. Objective: To assess the accuracy of judgments made by surrogate decision makers; ascertain the beliefs, practices, and clinical and sociodemographic factors ass ociated with accuracy of surrogates' decisions; assess the preferences of patients for life-sustaining treatments; and compare differences i n accuracy across diagnoses. Design: Cross-sectional paired interviews . Setting: Outpatient practices of three university hospitals. Patient s: 250 patients with terminal diagnoses of congestive heart failure, A IDS, amyotrophic lateral sclerosis, lung cancer, and chronic obstructi ve pulmonary disease (50 patient-surrogate pairs in each group) and 50 general medical patients and their surrogates. Measurements: The accu racy of surrogate predictions was measured by using scales based on 10 potential treatments in each of three hypothetical clinical scenarios . Results: Preferences varied according to mode of treatment and scena rio. On average, surrogates made correct predictions in 66% of instanc es. Accuracy was better for the permanent coma scenario than for the s cenarios of severe dementia or coma with a small chance of recovery (P < 0.001). In a binary legit model, the accuracy of substituted judgme nts was positively associated with the patient having spoken with the surrogate about end-of-life issues (odds ratio [OR], 1.9 [95% CI, 1.6 to 2.3]), the patient having private insurance (OR, 1.4 [CI, 1.1 to 1. 7]), the surrogate's level of education (OR, 1.5 [CI, 1.2 to 1.9]), an d the patient's level of education (OR, 1.7 [CI, 1.4 to 2.2]). Accurac y was negatively associated with the patient's belief that he or she w ould live longer than 10 years (OR, 0.6 [CI, 0.5 to 0.7]), surrogate e xperience with life-sustaining treatment (OR, 0.4 [CI, 0.3 to 0.5]), s urrogate participation in religious services (OR, 0.67 [CI, 0.50 to 0. 91]), and a diagnosis of heart failure (OR, 0.6 [CI, 0.5 to 0.8]). Age , ethnicity, marital status, religion, and advance directives were not associated with accuracy. Conclusions: The accuracy of substituted ju dgments is associated with multiple clinically apparent patient and su rrogate factors. This information can help clinicians identify conditi ons under which substituted judgments are likely to be accurate or ina ccurate and can help target populations for education designed to impr ove the accuracy of surrogate decision making.