Quality Standards
None of 3 assays on an Abbott Alinity can meet preferred measurement uncertainty goals
A recent study of Abbott Alinity thyroid function tests can be evaluated against the EFLM MAU and the preferred permissible uncertainties proposed by the leading authorities on mu.
Zero of 3 thyroid function assays on an Abbott Alinity cannot meet preferred measurement uncertainty goals
March 2023
Sten Westgard, MS
A recent letter to the editor in JALM benchmarked Abbott Alinity assays against the most recent preferred measurement uncertainty performance standards.
Measurement Uncertainty of Thyroid Function Tests on a Chemiluminescent Microparticle Immunoassay System Needs to be Improved. Borrillo F, Pasqualetti S, Panteghini M. JALM March 2023 08:02, 420-422. https://academic.oup.com/jalm/article-abstract/8/2/420/6988092?redirectedFrom=fulltext
This study looks at two Abbott Alinity instruments. and their individual performance as well as the performance measured between platforms.
The sources for these measurement uncertainty performance specifications can be found in these references:
- EFLM database, accessed 11/26/2022. https://biologicalvariation.eu/meta_calculations
- Performance specifications for measurement uncertainty of common biochemical measurands according to Milan models, Federica Braga and Mauro Panteghini, CCLM 2021; 59(8):1362-1368.
- Definition and application of performance specifications for measurement uncertainty of 23 common laboratory tests: linking theory to daily practice. Braga F, Pasqualetti S, Borrillo F, Capoferri A, Chibireva M, Rovegno L, Panteghini M, CCLM 2022 https://doi.org/10.1515/cclm-2022-0806
- Redesigning the surveillance of in vitro diagnostic medical devices and of medical laboratory performance by quality control in the traceability era. Mauro Panteghini. CCLM 2022. https://www.degruyter.com/document/doi/10.1515/cclm-2022-1257/html
There are just 3 thyroid function assays covered in the paper: TSH, FT3, and FT4. A single level of performance is measured for each of 2 Alinity analyzers, as well as a between-platform imprecision. So for each assay, there will be three measurements. The 2022-2023 papers from Panteghini et al provide the definitive, preferred specifications for permissible uncertainy (pU, or as well will refer to them, ppU). The EFLM database provides specifications for MAU, minimum and desirable, for all 3 analytes.
Abbott Alinity |
Level | MU | EFLM Desirable, Minimum MAU |
Preferred pU (ppU) |
Final verdict |
TSH | i08 | 5.38% | 26.5% (des) 17.7% (min) |
2.89% (des) |
Fails ppU |
i09 | 3.98% | Fails des ppU | |||
between-platform | 4.77% | Fails ppU | |||
FT3 | i08 | 5.99% | 5% (des) 7.5% (min) |
2.35% (des) 3.53% (min) |
Fails des MAU and ppU |
i09 | 4.36% | Fails ppU |
|||
between-platform | 5.24% | Fails des MAU and ppU | |||
FT4 | i08 | 5.17% | 4.9% (des) 7.4% (min) |
2.8% (des) 4.2% (min) |
Fails des MAU and ppU |
i09 | 4.88% | Fails ppU | |||
between-platform | 5.09% | Fails des MAU and ppU |
Notice that these assays always pass some form of the MAU, whether it is desirable or minimum, but always fail the ppU goals.
As we have seen with other assays, and other instruments, these new measurement uncertainty performance standards are harsh, perhaps impractically harsh, beyond the capability of even the most advanced instruments. That should raise concerns about the promulgation and mandatory implementation of these new goals throughout the world.