ORLANDO, Fla. — Steering clinicians toward a cascade approach for thyroid function testing cut unnecessary orders by a monthly average of 15% and concurrent orders by 19% per month, according to research presented at the College of American Pathologists (CAP) 2025.

The move, by Mayo Clinic Labs in Rochester, Minnesota, resulted in cost savings for the institution of $4000 a month, nearly $50,000 a year, based on federal reimbursement rates. 

If Normal Thyroid-Stimulating Hormone, No Further Testing

Mayo’s cascade approach begins with thyroid-stimulating hormone (TSH) as a screening assay. When TSH is normal, no additional testing is necessary. When the TSH is abnormal, appropriate tests will automatically be performed.

Mayo clinicians could choose the cascade approach or individual tests. But the cascade, which aligns with guidelines, was underused over the decade it had been available, Kim Terrio, MBA, a medical policy manager with the Division of Value-Based Medicine at Mayo, told Medscape Medical News.

Patterns at Mayo showed TSH was often being ordered together with free thyroxine (T4), total triiodothyronine, and/or antithyroid peroxidase. Many of these tests would have been unnecessary based on the TSH result, following the algorithmic approach.

“Providers sometimes aren’t aware of the cascade or sometimes just want all of the results,” Terrio said. “We were targeting those providers who were ordering these as stand-alone tests and guiding them toward the cascade.”

After getting approval from Mayo’s thyroid team, the researchers introduced an algorithm within their Epic electronic medical records system. If providers searched for any of the tests separately within the cascade, prompts would guide them toward the cascade, although they still have the option to order them individually.

After 1 year, Terrio said, average monthly concurrent orders dropped by 19%, and average monthly unnecessary orders decreased by 15% per month. “Additionally, volumes for the thyroid function cascade increased an average of 41% per month,” she said.

The streamlining is a win for patient care as well, she said. “We are ensuring patients receive only the testing that is necessary and at the correct time,” she said.

Widespread Implications for Common Test

Thyroid dysfunction and testing are common, so the research has widespread implications, said Brian Jackson, MD, MS, laboratory director and director of clinical pathology at University of Maryland Medical Center, Baltimore, who was not part of the study.

“Based on my own experience reviewing ordering volumes at different laboratories, there appears to be a significant amount of thyroid marker overordering as well as a lot of variability from place to place,” he told Medscape Medical News.

The Mayo approach “could easily be adapted to other settings,” he said. “While many laboratories have TSH reflex tests, I’m not aware of any others that use the full cascade described in the poster. The authors also describe a couple of potential unintended consequences from nonuser-friendly EHR [electronic health record] interfaces and how they avoided them.”

The study authors said the most common unintended consequence providers mentioned centered on difficulty finding tests after the intervention, which was addressed by adding synonyms within Epic to boost searchability. Another unintended consequence involved an increase in free T4 testing performed under an alternative test method using equilibrium dialysis. Researchers tweaked the algorithm to steer providers to order the correct free T4 test.

The cost-saving implications depend on several factors, Jackson noted, especially the patient’s insurance status.

“For patients who haven’t met their deductible or are subject to coinsurance, unnecessary thyroid testing could absolutely cause significant financial harm,” Jackson said. “And for cases where the testing is covered by insurance, unnecessary testing drives up costs for all of us.”

Terrio and Jackson reported having no relevant financial conflicts of interest. 

Marcia Frellick is an independent, Chicago-based healthcare journalist and a frequent contributor to Medscape Medical News.