Managing Measurement Bias in the Metrological Traceability Era: From IVD Surveillance to Laboratory Action
This review reframes how laboratories should understand and manage measurement bias now that IVD manufacturers bear primary responsibility for traceability-based bias correction. Residual bias from incomplete traceability implementation can be detected through external quality assessment, while randomly occurring bias from recalibration and lot changes should be monitored via internal QC and evaluated against measurement uncertainty specifications. The author provides a clear decision pathway for when laboratories versus manufacturers must act.
The original study
Not all biases are created equal: how to deal with bias on laboratory measurements.
- Authors
- Panteghini M
- Journal
- Clinical chemistry and laboratory medicine
- Type
- Journal Article, Review
- PMID
- 39585762
Original abstract
Although the concept of bias appears consolidated in laboratory science, some important changes in its definition and management have occurred since the introduction of metrological traceability theory in laboratory medicine. In the traceability era, medical laboratories should rely on manufacturers who must ensure traceability of their in vitro diagnostic medical devices (IVD-MD) to the highest available references, providing bias correction during the trueness transfer process to calibrators before they are marketed. However, sometimes some bias can be observed arising from an insufficient correction during the traceability implementation. This source of bias can be discovered by the IVD-MD surveillance by traceability-based external quality assessment and confirmed by ad-hoc validation experiments. The assessment of significance should be based on its impact on measurement uncertainty (MU) of results. The IVD manufacturer, appropriately warned, is responsible to take an immediate investigation and eventually fix the problem with a corrective action. Even if IVD-MD is correctly aligned in the validation steps and bias components are eliminated, during ordinary use the system may undergo systematic variations such as those caused by recalibrations and lot changes. These sources of randomly occurring bias are incorporated in the estimate of intermediate reproducibility of IVD-MD through internal quality control and can be tolerated until the estimated MU on clinical samples fulfils the predefined specifications. A readjustment of the IVD-MD by the end-user must be undertaken to try to correct the bias becoming significant. If the bias remains, the IVD manufacturer should be requested to rectify the problem.