Bias and uncertainty of the International Normalized Ratio determined with a whole blood point-of-care prothrombin time test device by comparison to a new International Standard for thromboplastin.
International Normalized Ratio
Point-of-care testing
Prothrombin time
Thromboplastin
Validation
Vitamin K-antagonist
Journal
Thrombosis research
ISSN: 1879-2472
Titre abrégé: Thromb Res
Pays: United States
ID NLM: 0326377
Informations de publication
Date de publication:
06 2021
06 2021
Historique:
received:
26
10
2020
revised:
04
02
2021
accepted:
10
02
2021
pubmed:
12
3
2021
medline:
22
6
2021
entrez:
11
3
2021
Statut:
ppublish
Résumé
Whole blood point-of-care PT/INR test devices, e.g. CoaguChek XS, are calibrated by their manufacturers. In the Netherlands, each new lot of test strips for CoaguChek XS is validated by a group of anticoagulant clinics collaborating with a Coagulation Reference Laboratory. In 2017, a new International Standard for recombinant human thromboplastin (coded rTF/16) has been established by the World Health Organization. To assess uncertainty of the validation procedure and the magnitude of the INR bias of a series of consecutive lots of test strips imported in the Netherlands. CoaguChek XS test strip INR results were compared to INRs determined with the new International Standard rTF/16. Comparisons were made with variable numbers of blood samples obtained from patients treated with vitamin K-antagonists. Relationships between CoaguChek XS and rTF/16 results were determined with orthogonal regression analysis. The relationships were used to assess bias and uncertainty of bias. Average bias between CoaguChek XS test results and rTF/16 depends on the INR level. Overall, there was a trend of increasing bias and increasing uncertainty with increasing INR values. Along the sequence of 47 consecutive lots, a temporary fluctuation of bias was observed. At an INR level of 3.0 the average bias was less than 10% in all cases, but at an INR of 4.0 there were 5 lots with average bias between 10 and 15%. Validation of test strips is useful to assess bias but depends on availability of fresh patients' samples and traceability to an accepted Reference Measurement System.
Sections du résumé
BACKGROUND
Whole blood point-of-care PT/INR test devices, e.g. CoaguChek XS, are calibrated by their manufacturers. In the Netherlands, each new lot of test strips for CoaguChek XS is validated by a group of anticoagulant clinics collaborating with a Coagulation Reference Laboratory. In 2017, a new International Standard for recombinant human thromboplastin (coded rTF/16) has been established by the World Health Organization.
AIM
To assess uncertainty of the validation procedure and the magnitude of the INR bias of a series of consecutive lots of test strips imported in the Netherlands.
METHODS
CoaguChek XS test strip INR results were compared to INRs determined with the new International Standard rTF/16. Comparisons were made with variable numbers of blood samples obtained from patients treated with vitamin K-antagonists. Relationships between CoaguChek XS and rTF/16 results were determined with orthogonal regression analysis. The relationships were used to assess bias and uncertainty of bias.
RESULTS
Average bias between CoaguChek XS test results and rTF/16 depends on the INR level. Overall, there was a trend of increasing bias and increasing uncertainty with increasing INR values. Along the sequence of 47 consecutive lots, a temporary fluctuation of bias was observed. At an INR level of 3.0 the average bias was less than 10% in all cases, but at an INR of 4.0 there were 5 lots with average bias between 10 and 15%.
CONCLUSION
Validation of test strips is useful to assess bias but depends on availability of fresh patients' samples and traceability to an accepted Reference Measurement System.
Identifiants
pubmed: 33706049
pii: S0049-3848(21)00073-6
doi: 10.1016/j.thromres.2021.02.018
pii:
doi:
Substances chimiques
Anticoagulants
0
Thromboplastin
9035-58-9
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
1-7Informations de copyright
Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.