[Evidence-based diagnosis in clinical practice: a patient with hypercholesterolemia]

Evidence-based diagnosis(EBD) is a method for clinical problem solving. The practice of EBD comprises five steps(formulating answerable clinical questions, searching for the best available evidence, critical appraisal of the evidence, application of the evidence to the patients, evaluation of execution of steps 1-4) as well as EBM. I present a case for studying the practice of EBD. The patient is a woman with hypercholesterolemia. It is essential to rule out secondary hypercholesterolemia. A test with high sensitivity is useful to rule out diseases. We call this situation SnNout(a High Sensitivity, a Negative result rules out diagnosis). The level of TSH is SnNout to rule out hypothyroidism with hypercholesterolemia. Clinical score is not SnNout, but may be useful in actual practice. The delay of relaxing phase of tendon reflex is not useful because of low sensitivity. Each clinical findings has a sensitivity and a specificity. It is important for clinicians to consider this fact.