In Clinical Standards in Medicine medical expert witness Barry E. Gustin, MD, MPH, FAAEM, writes:
One of the first clinical problems targeted for standards development was Chest Pain. As a prototypic example of clinical policy development, the Specialty Board responsible for the development and implementation of this standard created three conceptual entities which can be applied to all clinical problems. They are “actions”, “variables”, and “findings”.
Actions are defined as either “rules” (principles of good practice in most situations) such as ordering an electrocardiogram on an elderly patient with shortness of breath and severe chest pain, or “guidelines” (actions that should be considered but may or may not be performed depending on the patient, the circumstances, and a multitude of other factors) such as ordering imaging studies on any patient with chest pain. In those situations where a rule isn’t followed, the physician would be required to document in writing his justification for its avoidance.
Understanding the difference between rules and guidelines made it possible to create a rational categorization of the patient’s history and physical examination. Any patient presenting with chest pain, as a rule, should have a history taken which determines the character of the pain, any associated symptoms, and the patient’s past medical history. As a rule, the physician must also perform a physical examination that includes vital signs, and both a cardiovascular and pulmonary examination.