Background: Substituted judgment assumes adequate knowledge of patient's mind-set. However, surrogates' prediction of individual healthcare decisions is often inadequate and may be based on shared background rather than patient-specific knowledge. It is not known whether surrogate's prediction of patient's integrative life-story narrative is better.
Methods: Respondents in 90 family pairs (30 husband-wife, 30 parent-child, 30 sibling-sibling) rank-ordered 47 end-of-life statements as life-story narrative measure (Q-sort) and completed instruments on decision-control preference and healthcare-outcomes acceptability as control measures, from respondent's view (respondent-personal) and predicted pair's view (respondent-surrogate). They also scored their confidence in surrogate's decision-making (0 to 4 = maximum) and familiarity with pair's healthcare-preferences (1 to 4 = maximum). Life-story narratives' prediction was examined by calculating correlation of statements' ranking scores between respondent-personal and respondent-surrogate Q-sorts (projection) and between respondent-surrogate and pair-personal Q-sorts before (simulation) and after controlling for correlation with respondent-personal scores (adjusted-simulation), and by comparing percentages of respondent-surrogate Q-sorts co-loading with pair-personal vs. respondent-personal Q-sorts. Accuracy in predicting decision-control preference and healthcare-outcomes acceptability was determined by percent concordance. Results were compared among subgroups defined by intra-pair relationship, surrogate's decision-making confidence, and healthcare-preferences familiarity.
Results: Mean (SD) age was 35.4 (10.3) years, 69% were females, and 73 and 80% reported ≥ very good health and life-quality, respectively. Mean surrogate's decision-making confidence score was 3.35 (0.58) and 75% were ≥ familiar with pair's healthcare-preferences. Mean (95% confidence interval) projection, simulation, and adjusted-simulation correlations were 0.68 (0.67-0.69), 0.42 (0.40-0.44), and 0.26 (0.24-0.28), respectively. Out of 180 respondent-surrogate Q-sorts, 24, 9, and 32% co-loaded with respondent-personal, pair-personal, or both Q-sorts, respectively. Accuracy in predicting decision-control preference and healthcare-outcomes acceptability was 47 and 52%, respectively. Surrogate's decision-making confidence score correlated with adjusted-simulation's correlation score (rho = 0.18, p = 0.01). There were significant differences among the husband-wife, parent-child, and sibling-sibling subgroups in percentage of respondent-surrogate Q-sorts co-loading with pair-personal Q-sorts (38, 32, 55%, respectively, p = 0.03) and percent agreement on healthcare-outcomes acceptability (55, 35, and 67%, respectively, p = 0.002).
Conclusions: Despite high self-reported surrogate's decision-making confidence and healthcare-preferences familiarity, family surrogates are variably inadequate in simulating life-story narratives. Simulation accuracy may not follow the next-of-kin concept and is 38% based on shared background.
Keywords: Acceptability of healthcare- outcomes; Decision-control preference; End-of-life choices; Life-story narrative; Q-methodology; Substituted judgment; Surrogate decision-making; Surrogate decision-making confidence.