Assessment of the sunk-cost effect in clinical decision-making.

Despite the current push toward the practice of evidence-based medicine and comparative effectiveness research, clinicians' decisions may be influenced not only by evidence, but also by cognitive biases. A cognitive bias describes a tendency to make systematic errors in certain circumstances based on cognitive factors rather than evidence. Though health care providers have been shown in several studies to be susceptible to a variety of types of cognitive biases, research on the role of the sunk-cost bias in clinical decision-making is extremely limited. The sunk-cost bias is the tendency to pursue a course of action, even after it has proved to be suboptimal, because resources have been invested in that course of action. This study explores whether health care providers' medical treatment recommendations are affected by prior investments in a course of treatment. Specifically, we surveyed 389 health care providers in a large urban medical center in the United States during August 2009. We asked participants to make a treatment recommendation based on one of four hypothetical clinical scenarios that varied in the source and type of prior investment described. By comparing recommendations across scenarios, we found that providers did not demonstrate a sunk-cost effect; rather, they demonstrated a significant tendency to over-compensate for the effect. In addition, we found that more than one in ten health care providers recommended continuation of an ineffective treatment.