The Paradox of the Rational Patient and the Ethical Physician

MEDICAL DECISION MAKING is a gamble in which the patient is at risk and the physician is accountable. It is analyzed here as a formal mathematical problem in risk optimization. One solution is the BAYES DECISION RULE which minimizes personal risk and defines the decision logic of a rational patient according to EXPECTED UTILITY THEORY. A second solution is the MINIMAX DECISION RULE which minimizes the maximum value of categorical risks defined by the differential diagnosis. This solution mandates decision by lottery but defines a standard of equitable and impartial risk allocation. It is postulated here that MEDICAL ETHICS requires physicians to uphold this standard. However, the consequences are paradoxical. The decision making behavior of RATIONAL PATIENT and ETHICAL PHYSICIAN is divergent and irreconcilable. Physicians cannot achieve optimal diagnostic performance without violating medical ethics, and an ethical physician is inherently unpredictable. This theory can be tested by YERUSHALMY-GARLAND EXPERIMENT experiment.