How many times have you ordered a TSH/T4 on a hospitalized patient? If the test returns abnormal, it may have you wondering what to do – is further testing needed, or should you start the patient on levothyroxine? This Journal of Hospital Medicine article addresses the nuances of inpatient thyroid function testing.
Key Points:
- Nonthyroidal illness syndrome (NTIS), also known as sick euthyroid syndrome, is the biggest confounder of TSH testing in the hospital.
- NTIS can be caused by a host of other common clinical conditions among inpatients: infection, kidney or liver injury, malnutrition, MI, stroke, malignancy, or recent surgery.
- The prevalence of NTIS is 62%, while the prevalence of true unrecognized thyroid disease in inpatients is 1-2.5%. The high prevalence of NTIS means the specificity of TSH testing in inpatients is low.
When should we not order thyroid testing?
- Do NOT routinely order TSH on admission
- Do NOT order for patients on stable doses of thyroid hormone replacement
When should we actually order thyroid testing?
- Only if you have high clinical suspicion (I.e., high pretest probability) for thyroid dysfunction, specifically if there are 5+ symptoms
- May be reasonable in specific clinical scenarios where thyroid dysfunction is a reversible cause, such as: atrial fibrillation, SIADH, unexplained sinus tachycardia (after more common causes have been excluded), and delirium (after more common causes have been excluded)
- If NTIS is suspected, avoid further inpatient testing and consider outpatient testing once acute illness as resolved
How does decreasing inpatient thyroid testing benefit us?
- Saves healthcare dollars
- Prevents patient harm associated with overcasting or over treatment
- Decreases provider time spent ordering and interpreting abnormal results of unclear significance
Wendy Tong, IM PGY-2
Citation: Wootton T, Bates R. Things we do for no reason: routine thyroid-stimulating hormone testing in the hospital. J Hosp Med. 2020; 15(9): 560-562. doi:10.12788/jhm.3347