2014, Cilt 12, Sayı 3, Sayfa(lar) 107-114 |
|
Evaluation of Measurement Uncertainty for 25-Hydroxyvitamin D3 Immunoassay Method with |
Meltem Demir2, Fatma Demet İnce1 |
1Tepecik Eğitim ve Araştırma Hastanesi, Tıbbi Biyokimya, İzmir, Türkiye 2Özel Antalya Medikal Park Hastanesi, Biyokimya Laboratuvarı, Antalya, Türkiye |
Keywords: 25-Hydroxyvitamin D; uncertainty; immunoassay |
Background: It was calculated total uncertainty of measurement using the repeatability and the
uncertainty arising from the commercial quality control and calibrator in the method of immunoassay
25-Hydroxyvitamin D3 and was evaluated the potential impact of its on the decision of vitamin D status
of patients.
Materials and Methods: The measurement of 25-Hydroxyvitamin D3 was made with
electrochemiluminescence immunoassay method. After repeatability, the standard uncertainty arising
from the commercial quality control and calibrator were calculated, square of each value were collected
and the compound uncertainty was found with the square roots of that value. The expanded uncertainty
was obtained by multiplied the combined uncertainty value with a coverage factor (k=2; confidence
interval, 95%). Total 7922 results of vitamin D in 1-year was divided into 0-24, 25-49, 50-74, 75-150
nmol/L and the impacts on cut-off value of the measurement uncertainty and patients' vitamin D status
was evaluated.
Results: For the serum 25-Hydroxyvitamin D3 test, the total uncertainty of measurement was found as
±24% (confidence interval, 95%). When results were evaluated by adding or removing uncertainty of
measurement, the variation of individuals within diagnostic groups were significantly (p<0.001).
Conclusion: We thought that the 25-Hydroxyvitamin D3 immunassay methods provide greater speed,
easiness, efficiency and improve work flow in the clinical laboratory. However, the uncertainty of
measurement studies should be made if studied results with immunassay methods could significantly
affect clinical interpretations and patient management. Adding the value of the uncertainty of
measurement to the results of patient will increase the power of physician in the point of clinical
decision-making and confidence in the results of laboratory.
|
|
|