Thyroid Testing
Xchange newsletter - Winter 2006/2007
In 2006, new ‘UK Guidelines for the Use of Thyroid Function Tests’ (TFTs) were published. Here we take a look at thyroid disorders and the drivers behind the new guidelines.
Disorders of the thyroid rank among the most common medical conditions, particularly in women. Consequently, TFTs on blood samples account for 10 million requests each year in the UK and cost an estimated £30 million. They are used for both diagnosis and monitoring response to therapy. The majority of thyroid disorders present to and are initially managed within general practice.
Dr Graham Beastall, Glasgow Royal Infirmary, facilitated writing of the new guidelines, “There were numerous reasons for revising the guidelines. The previous set was ten years old and written before evidence-based medicine. New research has been published that has resulted in a lot of mixed messages. An increase in thyroid testing, partly due to the new GP contract, also made new guidelines necessary. In addition, there have been campaigns seeking to discredit TFTs, and confusion over reliability of the tests, so it was important to get the story straight.”
The new guidelines were developed by the Association for Clinical Biochemistry, the British Thyroid Association and the British Thyroid Foundation who looked at the issues concerned from three perspectives:
The patient’s perspective
Patients are becoming increasingly informed about their health. While there is much information available about thyroid disease, it can be confusing and is often conflicting. Patients expect that TFTs across the UK are uniform in terms of the tests performed, the results obtained and the interpretations made.
The physician’s view
With symptoms of thyroid disease being relatively non-specific, GP’s often turn to TFTs either to exclude or confirm diagnosis of thyroid disease. For borderline cases, the GP expects the laboratory to provide the combination of TFTs that provide the maximum information and welcome an interpretation of the results in difficult cases. For patients with known thyroid disease, GPs expect TFTs to provide information that assists with the optimisation of therapy.
The laboratory
Even though TFTs are relatively inexpensive, laboratory budgets have struggled to cope with the rapidly rising number of requests. Clinical biochemists endeavor to work with physicians to ensure that all requests are clinically justified. They also strive to obtain sufficient clinical information to ensure that they provide the optimal combination of TFTs for each individual patient.
The new guidelines were completed in June 2006 and comments on their accuracy and relevance are invited during the first year after publication. A full review is planned after three years. Graham commented that, “The guidelines have been well received and, while there is more research to be done, I believe they constitute a valuable reference source which can be used to facilitate clinical audit and inform future work.”
‘UK Guidelines for the Use of Thyroid Function Tests’ can be downloaded from:
The Association for Clinical Biochemistry <http://acb.org.uk/docs/tftguidelinefinal.pdf >
The British Thyroid Association <http://www.british-thyroid-association.org/guidelines.htm>
