Reducing Unnecessary Ordering of T3 Tests

Clinicians sometimes order multiple thyroid function tests at once (i.e., thyroid-stimulating hormone [TSH], thyroxine [T4], and triiodothyronine [T3]), when just one or two of these tests are clinically appropriate. In particular, T3 levels generally are helpful only for identifying so-called “T3 toxicosis” (i.e., hyperthyroidism with suppressed TSH but normal free T4). For the rare occasions when T3 measurement might be helpful, experts recommend total T3 rather than free T3, because the latter is more variable.

In this study, researchers studied the effect of an electronic “best practice advisory” that appeared when clinicians ordered total or free T3 levels at 10 hospitals and 11 ambulatory care centers in New York City. The advisory tel…