What is the role of Thyroid-Stimulating Hormone (TSH) in Medicare wellness visits?

From the Guidelines

Role of TSH in Medicare Wellness Visits

TSH testing is a crucial component of Medicare wellness visits, particularly for individuals with symptoms of thyroid dysfunction or a history of thyroid disease, as it helps identify abnormal thyroid function, which can have significant health implications if left untreated 1.

• The serum TSH test is the primary screening test for thyroid dysfunction, and multiple tests should be done over a 3- to 6-month interval to confirm or rule out abnormal findings 1.
• A normal TSH range is usually between 0.4 and 4.5 mU/L, but this can vary depending on the laboratory and individual factors, such as age, sex, and iodine intake 1.
• If the TSH level is abnormal, further testing and evaluation by a healthcare provider may be necessary to determine the underlying cause and develop an appropriate treatment plan, which may include medication such as levothyroxine (Synthroid) for hypothyroidism or methimazole (Tapazole) for hyperthyroidism 1.
• The optimal screening interval for thyroid dysfunction is unknown, but it is generally recommended to perform TSH testing once every 5 years for asymptomatic individuals aged 65 and older, or more frequently if symptoms persist or change 1.
• It is essential to note that evidence on the benefits of screening for thyroid dysfunction in asymptomatic individuals is lacking, and long-term randomized, blinded, controlled trials are needed to determine the effectiveness of this practice in improving important health outcomes 1.

From the Research

Role of Thyroid-Stimulating Hormone (TSH) in Medicare Wellness Visits

• TSH testing is a crucial component in assessing thyroid function during Medicare wellness visits 2, 3, 4.
• The test is used to diagnose hypothyroidism, a condition that affects one in 300 people in the United States, with a higher prevalence among female and older patients 2.
• Screening for thyroid dysfunction using TSH can detect symptomatic but unsuspected overt thyroid dysfunction, particularly in women older than 50 years of age 3.
• However, the evidence for the efficacy of treatment for subclinical thyroid dysfunction is inconclusive, and large randomized trials are needed to determine the likelihood that treatment will improve quality of life in otherwise healthy patients with mildly elevated TSH levels 3.

TSH Testing in Older Adults

• In older adults, screening for thyroid dysfunction using free T4 instead of TSH may improve efficiency in primary care by reducing reflex testing and increasing the positive predictive value for clinical hypothyroidism 5.
• Adjusting the TSH cutoff value from 4.2 to 6.5 mU/l can also result in a lower reflex test percentage and a higher positive predictive value 5.
• The use of TSH testing in older adults should be approached with caution, as subclinical hypothyroidism may not require treatment, especially in patients with mildly elevated TSH levels 4, 5.

Interpretation of TSH Test Results

• Primary care providers should have a thorough understanding of the interpretation of normal and mild abnormalities of thyroid function tests, including TSH, free T4, and anti-TPO antibodies 6.
• TSH is the best and often the only test needed for biochemical testing of the thyroid, and its results should be interpreted in the context of the patient's clinical presentation and medical history 6.