Evaluation of Measurement Uncertainty of Lithium Testing

Abstract

Purpose: Our aim was to calculate the measurement uncertainty of the lithium test in our laboratory and compare it with the % total allowable error (%TEa) values determined by international organizations. Materials and Methods: The study covers the period between 01 January 2021 and 30 September 2021. Data were obtained from the laboratory information system retrospectively. Lithium in serum samples are analyzed by spectrophotometric method in Siemens ADVIA 2400 autoanalyzer. The measurement uncertainty of the lithium test was calculated according to the Nordtest technical report 537. Results: The internal quality control uncertainty value for lithium testing was 4.37%, the external quality control uncertainty value was 2.093% and the extended uncertainty value was 13.92% at the 95% confidence interval in our study. Conclusion: In our study, the measurement uncertainty of the lithium test was found to be acceptable compared to the TEa% value determined by CLIA'88. However, it was determined to be outside the acceptable level according to the TEa% value determined by Rilibak. It is considered essential to enhance the quality standards of our laboratory tests, particularly the lithium testing. Calculating the measurement uncertainty of tests in laboratories and making them available when necessary can help improve the quality of laboratories and assist clinicians in making clinical decisions for their patients.

Keywords

• external quality control
• internal quality control
• measurement uncertainty