Effect of locus of control and consideration of future consequences on time tradeoff utilities for current health

Abstract
Comments from subjects undergoing utility assessment suggest that personality traits may affect responses. We sought to describe the association between time-tradeoff utility for current health and measures of two personality traits: (1) perceived control over one's life and (2) concern over immediate vs. future outcomes. One hundred subjects were recruited from the cafeteria of a large tertiary care hospital. Time-tradeoff utilities were assessed for current health relative to perfect health and death. Subjects also completed two previously validated scales, the Locus of Control (LOC), and Consideration of Future Consequences (CFC) instruments. The interview failure rate was less than 3%. The correlation between LOC score and utility for current health was modest (Spearman's ρ =0.196, p=0.071), but increased substantially when subjects unwilling to trade were excluded (Spearman's ρ =0.33, p=0.0043). The CFC scale was weakly correlated with utility for current health (Spearman's ρ =0.12, p=0.2676). The Consideration of Future Consequences scale explains little of the variation in time-tradeoff utilities. In contrast, Locus of Control appears to partially explain the variation in time-tradeoff utilities for current health, even after controlling for health status.