Reducing test request for anti-thyroglobulin and anti-thyroid peroxidase antibodies: trends before and after...

The objective of this study was to identify trends in requests for anti-thyroid peroxidase antibodies (TPOab) and anti-thyroglobulin antibodies (TGab) tests before and after applying set of interventions based on rejection rules and profile management.

Trend analysis was made at semester time intervals (from May-October 2010 to May-October 2017), before and after the intervention semester (May-October 2016). Number of tests (N) TPOab and TGab / 1000 total requests based on total N of both tests and total N of biochemical analysis laboratory requests, was calculated. To find out where the interventions had more impact we distinguished N of requests between Primary Care (PC) and Specialized Care (SC). A joinpoint regression analysis was used to determine time segments and time points in these indicators where the trend changed.

Trend analysis of the request of TPOab and TGab showed two clearly differentiated trend lines with a statistically significant Joinpoint (P < 0.001) with an increase in each semester from May 2010 of 7.4% and 7.5% respectively, to the semester of the interventions where there was a decrease of - 45% and - 61% located mainly in PC. Trend analysis in SC setting did not show any Joinpoint and any trend line.

Results showed that applied interventions enabled change of trend for TPOab and TGab test requests, especially in PC where the interventions proved to be the most successful.