Accurate laboratory results are essential for clinical decisions — but every measurement carries some uncertainty.
Addressing this challenge, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)–International Osteoporosis Foundation (IOF) Committee on Bone Metabolism has published a new study in Clinical Chemistry and Laboratory Medicine: Assessment of measurement uncertainty of immunoassays and LC-MS/MS methods for serum 25-hydroxyvitamin D .
The multicentre study evaluates the measurement uncertainty (MU) of various 25-(OH)D assays and their ability to detect physiologically relevant changes over time. Thirteen immunoassays and two LC-MS/MS methods for 25-hydroxyvitamin D [25(OH)D] were compared, applying strict analytical performance specifications to assess and compare their performance.
Lead author, Etienne Cavalier, Dept. of Clinical Chemistry, University of Liège, CIRM, CHU de Liège, Liège, Belgium, stated: "This new paper details how to calculate, interpret, and integrate measurement uncertainty (MU) into clinical practice, and includes a clear graphic illustrating MU estimation. It provides a practical tool for laboratories and clinicians to visualize variability and make informed decisions."
Why this matters:
- MU provides transparency in laboratory reporting
- It supports better patient care by framing results within their confidence limits
- It is a key step toward harmonization and quality improvement in vitamin D testing
Overall, this study highlights the persistent variability in 25-(OH)D assay performance despite ongoing standardization efforts. While LC-MS/MS methods have demonstrated superior accuracy and lower measurement uncertainty, certain immunoassays also met the established analytical performance specifications. The study underscores the importance of integrating measurement uncertainty into performance evaluations and introduces novel graphical representations to enhance the interpretation of assay reliability.
Professor Cavalier added, "Understanding measurement uncertainty is not just a matter of analytical rigor — it is a bridge between laboratory performance and patient outcomes. It is important that limitations such as inter-laboratory variability, potential matrix effects, and the absence of commutability assessments be considered when interpreting laboratory findings."
