Implementation of thyroid function tests algorithms by clinical laboratories: A four-year experience of good clinical...

Thyroid Function Tests (TFTs) are among the most commontly ordered tests. Significant overuse of TFTs can occur when instead of using a single TSH test to screen for thyroid disease a full panel (TSH plus FT4 and FT3) is ordered. The aim of our study was to evaluate the effectiveness of the application of a scientifically-established laboratory-controlled algorithm for TFTs to physician's orders for inpatients and to address potential pitfalls of such an approach.

We collected and analyzed Laboratory Information System data of the TFTs performed between April 2009 and March 2016 in a 739-bed tertiary teaching hospital. Between April 2013 and March 2016, we applied a laboratory controlled algorithm for inpatient TFT assays after TSH and did not perform further tests, unless a justified bypass was requested by the treating physician.

Algorithm application led to significant reductions of TFTs executed per TSH ordered. Compared to the four years preceding the intervention, executed FT4/TSH tests decreased from 93 to 18%, FT3/TSH from 92 to 18%, anti-TG/TSH from 18 to 4% and anti-TPO/TSH from 11 to 3%. Simultaneously, FT4, FT3, anti-TG, and anti-TPO tests ordered in outpatients also displayed a significant gradual decrease.

Hospital-based laboratories can safely apply a generally accepted TFTs algorithm on physician's orders without any compromise in diagnostic/therapeutic accuracy, thus achieving significant direct cost-reduction and increased physician awareness on current TFT ordering practices. Such an approach, combined with collaboration with ordering physicians, can safeguard patients from the consequences of low-value care practices.