Guidelines for preventive activities in general practice

Metabolic

Thyroid

      1. Thyroid

Metabolic | Thyroid

The prevalence of thyroid disease is approximately 10% in patients aged >50 years,1 with an additional 3.6% with unrecognised thyroid dysfunction (abnormal thyroid-stimulating hormone [TSH]).2 Autoimmune thyroid disease is the most common cause of thyroid dysfunction in Australia3 and 10–15% of the population have thyroid antibodies (more common in women than men).

Screening

Recommendation Grade How often References
Screening for thyroid dysfunction in asymptomatic adults is not recommended. Not recommended (strong) N/A 4,5
Routine screening for thyroid dysfunction in pregnant women is not recommended because of insufficient evidence. Generally not recommended N/A 5

Case finding

Recommendation Grade How often References
 
Testing for thyroid dysfunction is recommended in pregnant women with the following increased risks:
  • a history of thyroid dysfunction
  • symptoms or signs of thyroid dysfunction
  • a goitre
  • known thyroid antibody positivity
  • type 1 diabetes  
 Practice point As early as possible after six weeks gestation. 5,6

Although early detection and treatment of people with thyroid disease may help prevent morbidity and mortality, screening and treatment of asymptomatic patients can result in harm due to overdiagnosis and overtreatment.

There is currently insufficient evidence to determine the benefits and harms of screening asymptomatic people for thyroid disease.4 Thyroid imaging is only indicated if there is concern regarding structural abnormalities.

Although iodine deficiency was previously reported in Australia, iodised salt in bread became mandatory in Australia and New Zealand in 2009, and iodine deficiency is now very rare.7

Primary congenital hypothyroidism is screened as part of Australia’s Newborn Bloodspot Screening program.

There are no additional recommendations for Aboriginal and Torres Strait Islander people.

Case finding tests may be appropriate in these populations where there may be a higher prevalence of thyroid dysfunction:4,8

  • people with associated conditions (type 1 diabetes, coeliac disease)
  • Down syndrome
  • family history of thyroid disease
  • past history of thyroid disease
  • symptoms or signs of thyroid dysfunction.

For GP and patient resources about thyroid tests (and information about subclinical hypothyroidism):
First do no harm: A guide to choosing wisely in general practice | RACGP

  1. Walsh JP. Managing thyroid disease in general practice. Med J Aust 2016;205(4):179–84. doi: 10.5694/mja16.00545.
  2. Empson M, Flood V, Ma G, Eastman CJ, Mitchell P. Prevalence of thyroid disease in an older Australian population. Intern Med J 2007;37(7):448–55. doi: 10.1111/j.1445-5994.2007.01367.x.
  3. Australian Bureau of Statistics (ABS). Australian health survey: Biomedical results for nutrients. ABS, 2011 [Accessed 21 March 2023].
  4. LeFevre ML; U.S. Preventive Services Task Force. Screening for thyroid dysfunction: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2015;162(9):641–50. doi: 10.7326/M15-0483.
  5. Department of Health. Clinical practice guidelines: Pregnancy care. Canberra: Australian Government Department of Health, 2020 [Accessed 5 March 2024].
  6. The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). Subclinical hypothyroidism and hypothyroidism in pregnancy (C-Obs 46). RANZCOG, 2018 [Accessed 29 February 2024].
  7. Australian Institute of Health and Welfare. Folic acid & iodine fortification. Australian Government, 2016 [Accessed 5 March 2024].
  8. The Royal College of Pathologists of Australasia (RCPA). Thyroid function testing for adult diagnosis and monitoring. RCPA, 2017 [Accessed 5 March 2024].
This event attracts CPD points and can be self recorded

Did you know you can now log your CPD with a click of a button?

Create Quick log

Related documents

  Lifecycle-chart.pdf (PDF 0.12 MB)

Advertising