[What should an economically justified and reliable in-vitro diagnosis of thyroid function look like?]

On the basis of practical experience suggestions for an effective combination of laboratory tests of thyroid function are given. In addition to a reliable methodology a comprehensible interpretation of data is required; prerequisite is the knowledge of the circumstances under which the test serum was obtained. In a three-step-procedure, the diagnosis could be established solely on the basis of the results of T3 and T4 determinations in 70% of patients examined for the first time, and in a further 20% by an additional TRH test as a second step. In the third step determination of antibodies is employed for the differential diagnosis of doubtful cases.