title: Technical and clinical evaluation of the VITROS® Immunodiagnostic Products 25-OH Vitamin D Total Assay--comparison with marketed automated immunoassays and a liquid chromatography-tandem mass spectrometry method.
abstract: BACKGROUND
  The study was conducted to evaluate the technical and clinical performance of the VITROS® Immunodiagnostic Products 25-OH Vitamin D Total Assay, and compare it with the performance of five marketed automated assays and a liquid chromatography/mass spectrometry reference method (LC-MS/MS).
  
  
  METHODS
  Three hundred patient serum samples were used to compare the correlation of the VITROS® 25-OH Vitamin D Total Assay with both the other immunoassays and the LC-MS/MS method, using Passing-Bablok regression and Bland-Altman analyses. Concordance of the diagnosis of vitamin D status was calculated to test the agreement between the different assays. In addition, samples containing vitamin D2 were used to test the assay's ability to detect the D2 form of the vitamin.
  
  
  CONCLUSIONS
  These results from the VITROS® 25-OH Vitamin D Total Assay generally correlated well with those from most of the marketed immunoassays. Cross-reactivity of the D2 form was calculated as being close to 100%. Additionally, we found substantial variability in performance amongst the various assays, which suggests the need for optimisation and recalibration of commercial methods.
authors.forename: Etienne
authors.initials: E
authors.lastname: Cavalier
authors.forename: Olivier
authors.initials: O
authors.lastname: Rousselle
authors.forename: Nunzio
authors.initials: N
authors.lastname: Ferrante
authors.forename: Agnes
authors.initials: A
authors.lastname: Carlisi
authors.forename: Caroline
authors.initials: C
authors.lastname: Le Goff
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Souberbielle
mesh_terms: D000704:Analysis of Variance; D015982:Bias; D002853:Chromatography, Liquid / Q000592:standards*; D003429:Cross Reactions; D004872:Ergocalciferols / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000592:standards*; D014807:Vitamin D / Q000097:blood*
chemical_list: D004872:Ergocalciferols; D014807:Vitamin D