25-hydroxyvitamin-D3 analysis with high-performance liquid chromatography in terms of total analytical error and measurement uncertainty

Abstract

Objectives: Ensuring the accuracy and consistency of data obtained in the biochemistry laboratory is essential for obtaining reliable and comparable results. This study aims to calculate total analytical error (TAE) and measurement uncertainty (MU) values to assess the analytical performance of the 25-hydroxyvitamin D3 (25-OH vitD3) analyte measured using high-performance liquid chromatography (HPLC) in our laboratory. Methods: In our study, the internal quality control (IQC) results, which were analyzed at two levels daily between 01–01.2022–31.12.2022, and the data of the external quality control (EQC) program, which was performed at two levels per period for four periods per year, were retrospectively examined for the MU and TAE calculations of the 25-OH vitD3 analyte. TAE was calculated by the formula TAE% = Bias% + (1.65×CV%). MU has been calculated adhering to the Nordtest guideline. Results: In our study, while TAE values and U value calculated using EQC data for bias and u(bias) calculation were found to be higher than the analytical performance goals we used in our study, TAE values and U value calculated using IQC data for bias and RMSbias calculation were found to be lower than the analytical performance goals we used in our study. Conclusion: Clinical laboratories should evaluate analytical performance at regular intervals using appropriate methods. In cases where the number of participants using the same method and device in the EQC program is low, we recommend that EQC data not be used in the calculation of the bias component when evaluating analytical performance with TAE or MU.