Task Force concludes evidence is insufficient to recommend for or against thyroid dysfunction screening

Existing evidence is insufficient to recommend for or against screening for thyroid dysfunction in nonpregnant, asymptomatic adults, the U.S. Preventive Services Task Force (USPSTF) has concluded.

The USPSTF's recommendation was published online March 24 by Annals of Internal Medicine and was based on a previously published systematic review. It applies to asymptomatic nonpregnant adults without known signs or symptoms of disease.

The USPSTF found adequate evidence that “abnormal” serum levels of thyroid-stimulating hormone (TSH) can be detected by screening but determined that the definition of an abnormal TSH level is uncertain and that accurate interpretation is complicated. The USPSTF found inadequate evidence that screening for thyroid dysfunction in this population yields clinically important benefits and adequate evidence that screening and treatment does not improve quality of life or such measures as blood pressure, body mass index, bone mineral density, lipid levels, or cognitive function. Evidence on harms of screening and treatment was also deemed inadequate.

Based on the available evidence, the USPSTF concluded that the balance of benefits and harms of screening for thyroid dysfunction in nonpregnant adults who are asymptomatic cannot be determined. “If clinicians offer screening for thyroid dysfunction to asymptomatic persons, they should first ensure that patients clearly understand the uncertainties surrounding any potential clinical benefit of screening as well as the possibility of harm this choice may engender,” the authors wrote.

This recommendation replaces the previous USPSTF recommendation from 2004, which also found insufficient evidence to recommend for or against routine thyroid screening in nonpregnant asymptomatic adults. The current recommendation, however, restricted the definition of thyroid disease to symptomatic “overt” hypothyroidism and hyperthyroidism and emphasized that screening can detect biochemical abnormalities in addition to potentially important clinical disease.