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Research and Projects


Who is involved?

Theme: CLAHRC - Diagnostics & Stratified Medicine
Status: Live


UNTEST aims to help GPs make better use of blood tests when diagnosing thyroid dysfunction.

The thyroid gland is an important organ in the front of the neck which controls energy levels. Irregular thyroid function may cause a range of symptoms, such as tiredness, mood swings, irritability, dry skin, sweating, constipation and others. Since most of these symptoms are very common and could be found in many medical conditions, doctors order blood tests called thyroid function tests to check if the thyroid gland is working properly. 

In the past 20 years the number of thyroid function tests ordered has grown much faster than the number of patients with thyroid disease. The number of tests ordered by different GP practices varies a lot - even when the difference in the number of patients at each practice is taken into account. This suggests that there might be inappropriate ordering: tests are not ordered when needed, or too many tests are ordered unnecessarily.

This is problematic. If not ordered when necessary, treatable thyroid disease could be missed. If ordered unnecessarily, results could be misinterpreted, and could lead to more unnecessary tests and unnecessary and harmful treatment, thereby wasting rescources. 

UNTEST is led by members of the Exeter Test Group, which is an internationally recognised centre of excellence for test evaluation. For more information about the group, visit the research page


  • To find out why the number of thyroid function tests ordered by GPs is constantly growing without the corresponding increase in the number of patients who have thyroid function conditions. 

  • To assess the proportion of unnecessary thyroid function tests ordered.

  •  To develop interventions that could help GPs to order tests more apropriately.

  •  To evaluate the effectiveness and cost-effectiveness of such interventions. 


Project Activity

So far we have conducted three studies, the results of which were published in peer-reviewed journals: 

Variability in thyroid function test requests across general  practices in the South-West of England: An audit of routine data 

We analysed routine data on thyroid function tests (patients ≥16 years of age) carried out by two hospitals in South-West England (Royal Cornwall Hospital and Royal Devon & Exeter Hospital) during 2010 at the request of 107 general practices. A total of 195 309 TFT requests were made for 148 412 patients. We found six-fold variation in the number of tests per 1000 list size, most of which was due to heterogeneity across practices and only 24% of this was accounted for by prevalence of hypothyroidism (underactive thyroid) and socio-economic deprivation. 

Reasons for variation in ordering of thyroid function tests from the perspective of primary healthcare professionals: A qualitative study

To identify potential reasons for variation in the ordering of thyroid function tests, we carried out fifteen semi-structured interviews with primary healthcare professionals (general practitioners, practice nurses, practice managers) that used one laboratory of a general hospital in South West England. We used framework analysis to analyse views on test ordering variation at the societal, practice, individual practitioner and patient level. A number of reasons for variation in ordering across practices were suggested. These related to: primary healthcare professionals awareness of and adherence to national policy changes; practices having different protocols on thyroid function test ordering; the set-up and use of computer systems in practices; the range of practice healthcare professionals able to order thyroid function tests; greater risk-aversion amongst general practitioners and changes in their training and finally how primary healthcare staff responded to patients who were perceived to seek help more readily than in the past.

Effectiveness of interventions to reduce ordering of thyroid function tests: a systematic review 

We conducted a systematic review of the literature to identify studies evaluating the effectiveness of behaviour changing interventions designed to reduce indiscriminate ordering of thyroid function tests. We found 27 studies conducted in different countries and settings. Most of the studies reported positive results suggesting that the interventions are effective in reducing the volume and, to a lesser extent, the appropriateness of requests for thyroid function tests. However, the poor methodological quality and reporting of the studies, as well as the lack of studies evaluating the effectiveness of the modern electronic test ordering systems, precluded any firm conclusions and highlighted the need for further research. More information on the review can be found here.



Authors: Vaidya B., Ukoumunne O., Shuttleworth J., Bromley A., Lewis A., Hyde C., Patterson A., Fleming S., Tomlinson J (2013). Variability in thyroid function test requests across general practices in south-west England.

Authors: Hardwick R., Heaton J., Griffiths G., Vaidya B., Child S., Fleming S., Hamilton W., Tomlinson J., Zhelev Z., Patterson A., Hyde C (2014). Exploring reasons for variation in ordering thyroid function tests in primary care: a qualitative study.  

Authors: Zhelev Z., Abbott R., Rogers M., Fleming S., Patterson A., Hamilton W.T., Heaton J., Thompson Coon J., Vaidya B., Hyde C (2016). Effectiveness of interventions to reduce ordering of thyroid function tests: a systematic review.


Next Steps

To conduct a mixed-methods study evaluating the effectiveness of decision aids incorporated in the modern electronic test ordering systems. We hope that this will encourage more appropriate requesting of thyroid function tests.