Evaluation of long term thyroid replacement treatment. Swansea Vocational Training Scheme.

A group study was designed to test the need for the continued prescribing of thyroid replacement treatment. Seven doctors who were attending the vocational training scheme at Swansea studied a total of 75 patients. A withdrawal test for 21 days was used to assess the need for continued prescribing of thyroid medication. Sixty per cent (45) of the group studied had had either the wrong diagnosis or an incorrect maintenance dosage, 28% (21) did not need thyroid treatment after the withdrawal test, and 32% (24) had been prescribed an incorrect maintenance dosage of thyroxine as judged by the results of the initial estimation of thyroxine concentration. The medical and economic consequences of an appreciable rate of misdiagnosis and treatment are apparent.