Why Do Experts Disagree on Thyroid Screening?

Thyroid Screening? Why the Controversy?

Have you had a thyroid screen?

It's common to hear someone say, "Oh, I can't have a thyroid condition, because if I did, my doctor would have told me after my last physical."

Unfortunately, this is a mistaken sense of security for some people, because what they don't realize is that most physicals do not include any examination of the thyroid gland.

People who have a physical often have accompanying bloodwork -- typically a "complete blood count," known as a CBC, along with a cholesterol panel, and measurement of blood glucose levels, as well as other key factors.

But the bloodwork panel ordered by most physicians as part of an annual physical does not evaluate thyroid function. In order to test for thyroid problems, the physician must suspect a thyroid problem, and then decide specifically to add thyroid tests -- such as TSH, Free T4, and Free T3 -- to the bloodwork order. If the physician is not in "case-finding" mode -- or is not presented with obvious clinical signs and symptoms, the tests are not likely to be run.

So it's important for the public to realize that thyroid screening is not standard, it's not typically part of an annual physical, nor is it part of annual bloodwork for most patients. Having an annual physical, with its accompanying bloodwork, usually does not rule out or diagnose a thyroid condition.

Diagnosing thyroid disease requires a careful medical history, clinical examination, and thyroid bloodwork -- a combination of approaches that are rarely done unless a thyroid condition is already suspected, or a patient pushes for such tests.

But with various estimates that anywhere from 14 million to 47 million Americans have undiagnosed thyroid disorders, and the resulting symptoms and related conditions -- including depression, heart disease, infertility, and obesity -- it makes sense to consider whether thyroid screening should become standard.

At this point, it appears that the United States is very likely a long way from seeing any sort of standard thyroid screening becoming policy, because various organizations with a voice in the issue disagree on the value of thyroid screening.

According to the 2012 Clinical Practice Guidelines for Hypothyroidism in Adults: Co-sponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association, the greatest support for screening comes from the American Thyroid Association (ATA), which recommends thyroid screening in all adults beginning at age 35 years, and every 5 years thereafter.

On the other hand, the American Association of Clinical Endocrinologists (AACE) recommends routine TSH measurement only in older patients, and especially women. They have not, however, specified a particular age that qualifies as "older."

The ATA/AACE Clinical Practice Guidelines for Hypothyroidism in Adults recommend screening for hypothyroidism be considered in patients over the age of 60.

The American Academy of Family Physicians (AAFP) recommends routine screening only in asymptomatic patients older than 60.

And finally, the Royal College of Physicians of London, and the U.S. Preventive Services Task Force (USPSTF) do not recommend any routine screening for thyroid disease in adults.

(There are separate recommendations for screening related to thyroid disease in pregnancy.)

Why all the disagreement? There are several key factors at play that have an impact on the screening issue.

First, the medical community simply does not recognize that undiagnosed and untreated hypothyroidism has a significant impact on health, and quality of life. Therefore, it makes more sense to them to only address hypothyroidism when the symptoms or clinical signs become so evident, so significant and so burdensome to the patient that testing is clearly warranted. Essentially, patients have to wait until they are clearly suffering from overt hypothyroidism, and showing obvious clinical signs and symptoms, before testing, much less treatment, is warranted.

Next, there is obviously a financial motivation. In today's insurance-driven medical economy, thyroid screening often falls into the category of "unnecessary tests." Doctors and organizations can save money -- or earn bonuses or financial incentives -- by avoiding tests that are not considered absolutely essential from a medical standpoint. TSH tests, as well as other thyroid tests, cost money. So there is frequently pressure on practitioners not to order tests for screening purposes, and order thyroid tests only when there is overwhelming evidence that they are needed.

Finally, I would also argue that there is a gender bias and stigma surrounding thyroid disease that skews the quality of care in a way that negatively affects women. Women suffer from thyroid disease some seven to ten times more often than men. Symptoms can be vague -- like fatigue, depression, weight changes, body aches, hair loss -- and are often explained away -- sometimes derisively -- by practitioners who frequently blame lifestyle, diet, hormonal changes (like menopause), aging, or mental health issues. Some doctors claim that any overweight woman who wants a thyroid test has a mental problem, or is "drug-seeking". When you look at the bigger picture, from a bureaucratic perspective, it's easier and cheaper to blame women's lifestyles for their symptoms, or accuse them of ulterior motives, rather than run the thyroid tests. And, no surprise -- the majority of endocrinologists, who decide on these recommendations regarding screening, are men.

Despite what could be some very clear benefits, it appears that universal or even selected thyroid screening is not likely to be instituted in the near future, or perhaps even our lifetimes. * * *

Screening is just one of a number of controversies in the 2012 Clinical Practice Guidelines for Hypothyroidism in Adults.


Clinical Practice Guidelines for Hypothyroidism in Adults: Co-sponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association Online

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