Using the test assay results for total serum 25(OH)D (i.e., the sum of 25(OH)D 2 and 25(OH)D 3) determined for the single-donor samples and the RMP target values, the linear regression and 95% prediction intervals (PIs) were calculated. Results were received from 28 different laboratories using 20 ligand binding assays and 14 LC-MS/MS methods. SRM and PT/EQA samples evaluated included SRM 972a (four levels), SRM 2973, six College of American Pathologists (CAP) Accuracy-Based Vitamin D (ABVD) samples, and nine Vitamin D External Quality Assessment Scheme (DEQAS) samples.
A set of 50 single-donor serum samples were assigned target values for 25-hydroxyvitamin D 2 and 25-hydroxyvitamin D 3 using reference measurement procedures (RMPs).
An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum total 25-hydroxyvitamin D using ligand binding assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS).
0 kommentar(er)
