Comparison of the Serum Total 25-Hydroxyvitamin D Concentrations Using Chemiluminescent Immunoassay and Liquid Chromatography-Tandem Mass Spectrometry in Children

We aimed to assess the difference and agreement between the CL-series Vitamin D Total assay (Mindray), which was a kind of chemiluminescent immunoassay (CLIA) and liquid chromatography–tandem mass spectrometry (LC-MS/MS) in the measurement of serum 25-hydroxyvitamin D [25(OH)D] concentrations in children. We compared the 25(OH)D concentrations of 92 children using the CLIA and LC-MS/MS. Paired samples t-test was used to compare the two groups. Linear regression was used to show the correlation between CLIA and LC-MS/MS. The difference and bias between 2 methods were revealed in Bland-Altman plot. Agreement in classification of deficiency between CLIA and LC-MS/MS was assessed using Cohen’s Kappa. p value