Evaluation of harmonization among thyroid hormone testing systems: A comparative study based on external quality...

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Quality Assurance

Background:

• Thyroid hormone testing is crucial for diagnosing and managing endocrine disorders.
• Harmonization of thyroid hormone assays is essential for accurate clinical interpretation and inter-laboratory comparisons.
• External Quality Assessment (EQA) provides a framework for monitoring laboratory performance and identifying areas for improvement.

Purpose of the Study:

• To evaluate the harmonization of thyroid hormone tests (T3, T4, FT3, FT4, TSH) using EQA data.
• To guide laboratory quality enhancement initiatives.
• To assess the potential for big data interoperability in thyroid hormone testing.

Main Methods:

• Collected EQA data for T3, T4, FT3, FT4, and TSH from January 2022 to December 2024.
• Calculated total allowable error (TEa) for the laboratory (TEa-Lab) and peer groups (TEa-peer).
• Derived harmonization indices (HI) by comparing TEa values against biological variation thresholds (minimum, desirable, optimal).

Main Results:

• Thyroid-stimulating hormone (TSH) testing demonstrated desirable harmonization (HI ≤ 1).
• Harmonization indices for T3, T4, FT3, and FT4 ranged from 1.1 to 1.9, indicating suboptimal harmonization.
• Peer group analyses showed variable coordination among testing systems, with harmonization levels ranging widely.
• Harmonization levels between the laboratory and peer groups for thyroid hormones exhibited strong consistency.

Conclusions:

• Harmonization indices derived from EQA data quantitatively reflect the consistency of thyroid hormone testing systems.
• This approach aids in identifying laboratory-specific issues and implementing corrective actions.
• The findings provide a valuable reference for enhancing laboratory big data interoperability and supporting clinical decision-making.