Investigations for possible thyroid disease are very common and overall represent a significant cost for the healthcare budget in Australia.
There are concerns about the appropriateness of some testing. The inability to capture accurate information about the extent of investigations for thyroid disease makes it difficult to identify targeted interventions that could improve appropriateness of care and ensure wise use of resources.
The recommendations in the general section about improving collection and public reporting of MBS data, and ensuring that the information is collected in a way that allows meaningful audit and feedback about their practice to clinicians, are particularly applicable to the items in this chapter.
Measuring thyroid stimulating hormone (TSH) is recommended as the single first-line test for possible thyroid dysfunction. More comprehensive tests of thyroid function – TSH plus free tri-iodothyronine (T3) and/or free thyroxine (T4) – are recommended only if TSH is abnormal or for investigation of certain conditions. The rate of thyroid function testing has increased in Australia, faster than the rate of population growth.35 The fast growth of thyroid testing in Australia suggest that there is over‑testing.
The Atlas found that, in 2016–17, 5.5 million TSH tests and 2.3 million thyroid function tests (TSH plus T3 and/or T4) were ordered in Australia. This is likely to be an underestimate of testing rates, as a result of characteristics of the way data are captured.
Neck ultrasound can be used to investigate thyroid nodules and goitre. One of the reasons for thyroidectomy (removal of the thyroid) is to treat malignant thyroid nodules.
The Atlas found that the rate of neck ultrasound varies up to six-fold, and the rate of thyroidectomy varies up to five-fold, between local areas in Australia. Underlying patterns of disease are unlikely to fully explain the variations seen.
3a. The MBS Review Taskforce to advise on how the data collected by the MBS could provide clinically meaningful information to allow regular audit and feedback to clinicians on the appropriateness of use of tests, as well as accurate public reporting on use of healthcare resources. In relation to thyroid function tests, the taskforce could advise on:
*Episode coning in the MBS means that, when more than three tests are requested by a general practitioner (GP) per patient attendance, benefits are paid only for the three tests with the highest fees. If a GP requests a test with three other more expensive tests, it is ‘coned out’ and may not be included in the MBS dataset.
3b. Relevant colleges and clinical societies to agree on a nationally consistent approach to providing standardised, high-quality thyroid ultrasound reports, such as using the ATA (American Thyroid Association) guidelines or the TI-RADS (Thyroid Imaging Reporting and Data System) score to support general practitioner decision-making and help reduce unnecessary repeat ultrasounds.