If a patient comes into the treatment, a doctor usually has to answer the following questions:
A physician must balance a variety of clinical data cope and is exposed to high expectations towards the patients and their families and against the hospital and the health system. He has to decide what information he needs, what tests should be done, how the results are interpreted and can be merged for diagnostic hypotheses and what treatment is appropriate – this topic is called “clinical decision making.” If a patient comes into the treatment, a doctor usually has to answer the following questions: What disease does this patient? Should this patient be treated? If tests are performed? In simple or everyday situations doctors decide informally; Diagnoses are made by identifying typical diseases, and the tests and treatment should be initiated on the basis of established practice. For example, it is very likely during a flu epidemic that an otherwise healthy adult is diagnosed with fever, body aches and cough for two days as a case of influenza at best treated symptomatically. Such detection of disease patterns is efficient and easy to use, but can also be wrong, because the diagnostic and therapeutic options are not seriously or systematically considered enough. For example, it could be that a patient with this pattern and decreased O2 saturation does not have flu, but a bacterial pneumonia and thus need antibiotics. In more complex cases, a structured, quantitative, analytical methodology can be a better approach to decision making. Even if the pattern recognition detects the most likely diagnosis possibility of an analytical decision-making is often used to confirm the diagnosis. Analytical methods can be the application of the principles of evidence based medicine, the use of clinical guidelines, and the use of various specific quantitative techniques (eg. B. Bayes theorem).