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Standardizing 25-hydroxyvitamin D data from the HunMen cohort
1Department of Laboratory Medicine, University of Debrecen, Nagyerdei Blvd 98, Debrecen, H-4032, Hungary.
Summary
Standardizing 25-hydroxyvitamin D (25OHD) measurements is crucial. This study presents a practical method using NIST values to correct lab results, improving accuracy and reducing hypovitaminosis D prevalence.
Area of Science:
- Clinical Chemistry
- Biochemistry
- Laboratory Medicine
Background:
- Accurate measurement of 25-hydroxyvitamin D (25OHD) is essential for clinical diagnosis and management.
- Current 25OHD assays lack standardization, leading to significant inter-laboratory variability and potential misdiagnosis.
- External Quality Assessment Schemes (EQAS) provide valuable data for assessing and improving assay performance.
Purpose of the Study:
- To develop and validate a practical method for standardizing 25-hydroxyvitamin D (25OHD) values in routine diagnostic laboratories.
- To correct measured 25OHD values using linear regression against National Institute of Standards and Technology (NIST) target values.
- To assess the impact of standardization on the prevalence of hypovitaminosis D.
Main Methods:
- A linear regression model was developed using data from the Vitamin D External Quality Assessment Scheme (DEQAS).
- The model utilized the relationship between laboratory-measured total 25OHD and NIST total target values (TV) for DEQAS survey samples.
- The developed standardization approach was applied to 206 samples from the HunMen cohort measured by chemiluminescence immunoassay (CLIA).
Main Results:
- Standardization using the NIST-DEQAS linear regression model significantly adjusted the mean total 25OHD in the HunMen cohort from 53 to 62 nmol/L.
- The prevalence of hypovitaminosis D (<75 nmol/L) in the cohort decreased substantially from 84% to 72% after standardization.
- The method demonstrated a practical approach for routine diagnostic laboratories to address non-standardized 25OHD values.
Conclusions:
- A simple and practical method for standardizing 25-hydroxyvitamin D (25OHD) measurements is proposed.
- Correction using NIST target values via DEQAS provides a viable solution to the challenge of non-standardized 25OHD values.
- This approach can improve the accuracy of 25OHD reporting and clinical decision-making.
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