Traditional determination of medical prognoses for informed decision making on the part of both physicians and patients has relied upon frequentist statistical methods. We will discuss the potential for application of game theoretic measures to improve analyses of probabilities of trajectories and ultimate health outcomes from presented signs and symptoms, or lack thereof. Using game theoretic measures, we will re-examine survival analyses, estimations of relative risk, and many other standard tools in medical prognosis, especially for progressive and/or chronic illnesses.