Managing thyroid conditions in primary care

Finding a balance between when to test, what to test and how to treat

Managing thyroid conditions in primary care

Key points

  • Requests for thyroid tests are increasing although in many cases clinical need is not evident.
  • TSH should not be used as a screening test for non-pregnant asymptomatic patients.
  • Measure TSH alone as the first test for suspected thyroid disorders.
  • Base repeat testing decisions on patient symptoms and other indicators, such as comorbidities, regular medicines, age, gender and TSH levels. 
  • Levothyroxine sodium, the new ingredient name for thyroxine sodium, is treatment of choice for hypothyroidism.
  • Reserve thyroid ultrasound to assess visible or palpable thyroid nodules or goitre on clinical examination.
  • Where imaging is indicated, ensure all appropriate clinical details are provided on the referral.
 

Medicinewise News: Thyroid disease: challenges in primary care

<img src=

Thyroid dysfunction is common, but thyroid testing should only be requested after a detailed clinical history and targeted physical examination have suggested thyroid problems.

Read the full article

 

Choosing Wisely Australia

<div class=

Choosing Wisely Australia is an initiative that brings the community together to improve the quality of healthcare through considering tests, treatments and procedures where evidence shows they provide no benefit or, in some cases, lead to harm.

Led by Australia’s colleges, societies and associations and facilitated by NPS MedicineWise, Choosing Wisely Australia challenges the way we think about healthcare, questioning the notion 'more is always better'

Recommendation from the Royal Australian College of General Practitioners


Recommendations from The Endocrine Society of Australia

Don’t order a total or free T3 level when assessing thyroxine dose in hypothyroid patients

 

Thyroid conditions: test, treat, refer?

<img src=

Thyroid conditions are a common presentation in primary care. When used appropriately, thyroid function tests can help inform management of people with thyroid diseases, and monitor response to treatment. 

Read the full article

 

Supporting quality use of referrals

<img src=

The information provided on an imaging or pathology request form has a direct impact on patient care and safety

Learn more

 

Australian Prescriber: Thyroid disorders in pregnancy and postpartum

<img src=

Ashleigh Smith, Jade Eccles-Smith, Michael D’Emden, Karin Lust

Aust Prescr 2017;40:214-9

Thyroid dysfunction in pregnancy has consequences for mother and baby. Potential problems include pre-eclampsia, prematurity and congenital abnormality.

Read the full article

Guidelines

Bone and Metabolism Expert Group. Therapeutic Guidelines: Thyroid disorders. 

Newly revised in June 2019, the Therapeutic Guidelines: Bone and metabolism address the diagnosis, monitoring and treatment of hypothyroidism (including subclinical presentation), hyperthyroidism (also subclinical presentation) and also discusses how to interpret thyroid test results.

 

For your patients

  • Better Health Channel - information on common thyroid conditions and some common treatments.
  • Health Direct - information on common thyroid conditions such as hyper- and hypothyroidism.
  • Lab Tests Online - accurate information for consumers about pathology testing.
  • The Australian Thyroid Foundation - offers support, information and education about the impact of thyroid disease and the benefits of good thyroid health.

5 questions to ask your doctor or other healthcare provider is a resource that can help patients ensure they end up with the right amount of care.

Testing and screening

ReferencesSummary

Schneider C, Feller M, Bauer DC, et al. Initial evaluation of thyroid dysfunction - Are simultaneous TSH and fT4 tests necessary? PLoS One 2018;13:e0196631.

This study based on analysis of cross-sectional data from Busselton (Western Australia) investigated whether testing TSH first, then assessing free T4 only if TSH is out of the reference range, would miss cases of hyperthyroidism or hypothyroidism. The alternative diagnostic scenario was to request both TSH and free T4 at the same time. It found that 93.0% of individuals had normal TSH and would not need further testing. Only 3.8% of individuals had a normal TSH and a free T4 outside the reference range and so would potentially be missed if testing is staggered rather than concurrent. However, in 85% of these cases, the free T4 was within 2 picomole/L of reference range limits, consistent with healthy outliers. This suggests that only about 0.57% of individuals with thyroid dysfunction would be missed by staggering TSH tests rather than measuring both TSH and free T4 at the same time.

The study did not support the simultaneous initial measurement of both TSH and T4.

LeFevre ML. Screening for thyroid dysfunction: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2015;162 (9):641-50.

Screening for thyroid dysfunction in non-pregnant people without clinical symptoms is not recommended by the US Preventive Services Task Force (USPSTF). 

This guideline found:

  • insufficient evidence to assess the balance of benefits and harms of screening for thyroid dysfunction
  • insufficient evidence of benefit of screening for thyroid disease in reducing cardiovascular disease
  • adequate evidence that in asymptomatic adults does not improve quality of life or meaningfully improve body mass index (BMI), blood pressure, bone mineral density or lipid levels
  • adequate evidence that while screening can detect 'abnormal' serum TSH levels in asymptomatic persons, what constitutes an abnormal TSH level is uncertain. It noted that there is professional disagreement about the appropriate cut points for the lower and upper boundaries of normal TSH levels and accurate interpretation is further complicated by measurement variability and the sensitivity of TSH secretion to conditions other than thyroid dysfunction.

Interventions to reduce thyroid testing

ReferenceSummary

Zhelev Z, Abbott R, Rogers M, et al. Effectiveness of interventions to reduce ordering of thyroid function tests: a systematic review. BMJ Open 2016;6 (6):e010065.



This systematic review identified 27 studies conducted across UK/Europe, North America, Australia and new Zealand.  
Fourteen studies were conducted in a hospital setting and the remainder in primary care or community settings.

In most studies, the recommended testing strategy was based on TSH as a single first-line test for suspected thyroid dysfunction. Education, guidelines/protocols and audit and feedback were the most common types of interventions used. Reminders and decision tools were less commonly used, and changes to funding and evaluation of computer-based test requesting were used in few studies.

Single-mechanism interventions were effective in decreasing test volume or cost, changing patterns of TFT requesting, or improving compliance with guidelines. All but one of the multi-modal interventions were effective in decreasing volume of test requesting, changing the pattern of testing requesting, avoiding unnecessary testing or decreasing test-related expenditure.

Although interventions varied in terms of targeted audience, content, intensity, frequency and method of delivery, the authors suggested these differences had limited impact on reported effectiveness. Interventions that raise clinicians' awareness of existing guidelines, translate them into easy to follow rules and embed them in decision aids were considered a potentially effective combination.

Most of the studies were deemed of poor or moderate quality based on selection bias, lack of blinding and failure to control for confounders.

Overdiagnosis

ReferencesSummary

Pandeya N, McLeod DS, Balasubramaniam K, et al. Increasing thyroid cancer incidence in Queensland, Australia 1982-2008 - true increase or overdiagnosis? Clin Endocrinol (Oxf) 2016;84 (2):257-64 

This Queensland study reported an increase in thyroid cancer incidence from 2.2 per 100,000 persons in 1982 to 10·6 per 100,000 in 2008. The largest rise was seen for incident papillary thyroid cancers suggesting overdiagnosis is a factor driving the increase in incidence. However, there was also an increase in the number of more advanced-stage cancers suggesting that other factors are also driving the increase. The authors of the study suggested that lifestyle and environmental factors such as increasing obesity or increased exposure to radiation may also be playing a role.

O'Grady TJ, Gates MA, Boscoe FP. Thyroid cancer incidence attributable to overdiagnosis in the United States 1981-2011. Int J Cancer 2015;137 (11):2664-73. 


This US study using cancer registry data estimated that the proportion of incident papillary thyroid cancers attributable to overdiagnosis in 2011 was 5.5% and 45.5% in men ages 20–49 and 50 years or older, respectively. Among women aged 20-49, 41.1% of incident papillary thyroid cancers were attributable to overdiagnosis and in women 50 years or older, this rose to 60.1%. The authors estimated that overdiagnosis has resulted in an additional 82,000 incident papillary thyroid cancers that likely would never have caused any clinical symptoms.