Beyond Personality Traits and Financial Incentives: Bias and Variation in Medical Practices as a Systematic Result of Experiential Learning

摘要

There are several indicators of abundant sub-optimal decisions in medicine. Two of the common ones are overuse of defensive medical practices such as medical tests (bias toward more tests), and variation of medical diagnoses and treatments for medically similar patients (practice variation). Besides patients' characteristics and preferences, and the regional characteristics (such as culture), the most common explanations for practice variation and bias relate to physicians' personality traits (e.g., the level of risk aversion) and their financial incentives. We develop a theory that offers a new explanation for variation and bias in practice. With the help of a simulation model, we show that practice variation and bias do not have to be caused by personality traits and financial incentives, but can endogenously emerge through daily practices and outcome learning even among physicians with similar training working in the same region. In other words, the characteristics of medical tasks themselves can result in practice variation and bias. Specifically, a physician's exposure to outcome feedback, a physician's ability to evaluate different forms of practice, and a physician's accumulated experience with a given approach all contribute to practice variation and bias. A preliminary validation of the results is achieved by comparing projected results with actual data from cesarean section surgery in the states of New York and Florida.