ISEMPH Presentation: Joe Alcock
"Identifying normal function in abnormal results: Reaction norms lead to a new normal for medical practice"
Department of Emergency Medicine
University of New Mexico
Physicians use departures from normal values in vital signs and biomarkers to discriminate between health and disease, often with the goal of restoring values to normal ranges. However, overreliance on abnormal test results can result in overtreatment and medical errors. Using the examples of altitude exposure and pregnancy, we draw upon the concept of reaction norms which suggests that organisms, including humans, evolved a capacity to respond to conditions by changing their state. In these conditions, interventions aiming to return the patient to population-based normal values are misguided. Some overtreatment could be avoided if physicians recognized some parameter changes as “new normals” and had tools to distinguish between appropriate responses and pathological ones. We propose 4 heuristics for identifying appropriate responses, forming the acronym DOCS: Death is not typically a result of the Deviation, Other Organisms do not benefit, the reaction is a Complex and Coordinated response that is Stereotypical, including evidence of a new Setpoint. We show how these heuristics can be applied to distributions of test results from critically ill patients from the University of New Mexico and suggest ways to prospectively test candidate “new normals”, so that doctors can return to treating the patient, not the numbers.