Background: Historically, methodological differences and lack of standardization led to between-laboratory variability in 25(OH)D results. Recent observations raised concern about persisting variability. This quality assurance exercise investigated 25(OH)D result comparability between laboratories.
Methods: Serum pools (n=25) were prepared to contain endogenous 25(OH)D(2) and 25(OH)D(3) at 25(OH)D concentrations from ~12 to 150 nmol/l (5-60 ng/ml). Aliquots were sent to 8 laboratories utilizing various 25(OH)D assay methods including high performance liquid chromatography with ultraviolet detection (LC-UV), LC with tandem mass spectroscopy detection (LC-MS/MS) or an automated immunoassay (Diasorin Liaison). The LC-UV results were selected as a referent to which all others were compared using linear regression and Bland-Altman analysis.
Results: Good correlation (R(2)=0.87 to 0.97) was observed for all laboratories. Modest systematic bias was observed for some laboratories ranging from a positive mean bias of 10.5 nmol/l (4.2 ng/ml) to a negative mean bias of 3.5 nmol/l (1.4 ng/ml). For the laboratory with the greatest bias, 22/25 results were numerically higher (mean +15.7%) than LC-UV results. For Liaison, the primary error was likely random, whereas the major LC-MS/MS assay error source was biases likely due to calibration issues.
Conclusions: Modest inter-laboratory variability persists in serum 25(OH)D measurement. The National Institute of Standards and Technology 25(OH)D Standard Reference and calibration materials will further improve between-laboratory agreement for chromatography-based assays.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058672 | PMC |
| http://dx.doi.org/10.1016/j.cca.2010.08.018 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Comparison of laboratory-based and non-laboratory-based cardiovascular risk prediction tools in rural India.
Trop Med Int Health
January 2025
Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, Victoria, Australia.
Background: Non-laboratory-based cardiovascular risk prediction tools are feasible alternatives to laboratory-based tools in low- and middle-income countries. However, their effectiveness compared to their laboratory-based counterparts has not been adequately tested.
Aim: We compared estimates from laboratory-based and non-laboratory-based risk prediction tools in a low- and middle-income country setting.
Diffusion-weighted MRI in the identification of renal parenchymal involvement in children with a first episode of febrile urinary tract infection.
Front Radiol
November 2024
Department of Radiology, Giannina Gaslini Institute (IRCCS), Genoa, Italy.
Aims: This study aims to assess the diagnostic accuracy of diffusion-weighted Magnetic Resonance Imaging (DW-MRI) and determine the inter-reader agreement between two expert radiologists in detecting pyelonephritic foci during the initial episode of febrile urinary tract infection (fUTI) in children aged 0-5 years. Also, we aim to establish the correlation between clinical data and DW-MRI findings.
Methods: Children aged 0-5 years presenting with their first episode of fUTI were included in the study and underwent DW-MRI and Ultrasound (US) examinations within 72 h of admission.
Comparison of basic lymphocyte phenotype results between a diagnostic and a research laboratory.
Lab Med
November 2024
Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, CA, US.
Objective: Lymphocyte phenotyping is a valuable tool for monitoring the effects of antiretroviral therapy on individuals living with HIV-1. A switch study was conducted to compare T-cell subset quantification performed by a research laboratory and a diagnostic, laboratory to understand the impact on the retrospective and prospective results of a long-term study.
Methods: Using FACSCanto II Flow Cytometers, EDTA anticoagulated peripheral blood from 73 males enrolled in the Multicenter AIDS Cohort Study/Women Interagency HIV Combined Cohort Study was analyzed by both a research (laboratory 1) and a diagnostics laboratory (laboratory 2) for quantification of cluster of differentiation (CD)3, CD4, and CD8 T-cells.
Comparison of etonogestrel bioanalytical assay results in plasma and serum within and across laboratories.
Contraception
October 2024
Antiviral Pharmacology Laboratory, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address:
Article Synopsis
- This study aimed to compare how different laboratories measure etonogestrel, a contraceptive hormone, focusing on accuracy and precision across six labs (five academic and one commercial).
- In tests with prepared serum and plasma samples, four labs achieved accurate results within ±15% of expected concentrations, while high precision was demonstrated, with minimal variation across results.
- However, while individual labs generally correlated well with a reference lab for serum samples, some showed biases resulting in consistently higher or lower readings, highlighting variability in etonogestrel measurement methods across different facilities.
Von Willebrand Factor (VWF) multiplex activity assay differentiation of type 1 von Willebrand Disease (VWD) and variant VWD.
Haemophilia
January 2024
Versiti Blood Research Institute (VBRI), Milwaukee, Wisconsin, USA.
Introduction: VWD diagnosis is challenging requiring multiple VWF activity tests using many individual assays. We have developed an ELISA-based VWF Multiplex Activity Assay (VWF-MAA) to address this concern; however, the ability of the VWF-MAA to discriminate between type 1 VWD, variant VWD, and normal subjects has not been evaluated.
Aim: To evaluate the VWF-MAA and its ability to differentiate between type 1 VWD, variant VWD and normal subjects in individuals undergoing an initial laboratory evaluation for bleeding.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!