ABSTRACT
The classic medical diagnostic paradigm emphasizes the presence of “signature” symptoms for a particular diagnosis or syndrome, i.e. symptoms thought characteristic (sensitive and specific), or even unique for a specific medical diagnosis. A classic example is cardiac angina. Here the signature symptom is the localized mid-chest (substernal) pressure-type pain, with radiation to the inner aspect of the left arm, or jaw. Pain may be associated with shortness of breath and is typically transient and intermittent, characteristically occurring after exercise, cold exposure, or cigarette smoking, with relief by rest. Diagnosis of angina may be made by a combination of characteristic symptoms and examination tests (electrocardiographic changes, treadmill testing, cardiac catheterization, radionuclide studies, etc.). For angina, the characteristic symptom profile has been incorporated into a standard questionnaire which is subsequently validated for both clinical use and epidemiologic surveillance in populations (Rose et al. 1977).
