We would all wish that TSH and FT4 tests were absolutely standardised. That is, the results from any lab would be directly comparable to those from any other lab - worldwide.
My concern is that standardisation might not deliver what we hope. For example, if tests are improved (e.g. made more resistant to interference by antibodies or biotin), how do the changes implied by that get consistently incorporated into the standardised assays?
Clin Chim Acta. 2016 Apr 27. pii: S0009-8981(16)30157-7. doi: 10.1016/j.cca.2016.04.032. [Epub ahead of print]
Monitoring the stability of the standardization status of FT4 and TSH assays by use of daily outpatient medians and flagging frequencies.
De Grande LA1, Goossens K1, Van Uytfanghe K2, Das B3, MacKenzie F4, Patru MM5, Thienpont LM6; IFCC Committee for Standardization of Thyroid Function Tests (C-STFT).
1Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
2Ref4U, Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
3Biochemistry and Immunology Laboratory, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Mumbai, India.
4Birmingham Quality/UK NEQAS, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
5Ortho-Clinical Diagnostics, Inc., Rochester, NY, USA.
6Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium. Electronic address: firstname.lastname@example.org.
Clinicians diagnose thyroid dysfunction based on TSH and FT4 testing. However, the current lack of comparability between assays limits the optimal use of laboratory data. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) gave a mandate to the Committee for Standardization of Thyroid Function Tests (C-STFT) to resolve this limitation by standardization.
Recently, the Committee members and their partners felt ready to set the step towards the technical recalibration. However, before implementation, they were furthered by the Food and Drugs Administration (FDA) to develop a tool to assess the sustainability of the new calibration basis. C-STFT began to use 2 online applications, i.e., the "Percentiler" and "Flagger", with the intention to assess their utility for this purpose. The tools monitor the course of instrument-specific moving medians of outpatient results (Percentiler) and flagging rates (Flagger) from data of individual laboratories grouped by instrument/assay peer. They additionally document the mid- to long-term medians, hence, are quality indicators of stability of performance of both laboratories and peers/assays. Here, the first experiences built up in the pre-standardization phase are reported. They suggest the suitability of both applications to document the sustainability of the calibration basis in the post-standardization phase.
Copyright © 2016 Elsevier B.V. All rights reserved.
Committee for Standardization of Thyroid Function Tests; International Federation of Clinical Chemistry and Laboratory Medicine; Median; Outpatient; Population variation; Quality indicator
PMID: 27132242 [PubMed - as supplied by publisher]
As so often, the full paper is behind a paywall.