Simplified methods for local correction of system international normalized ratio

Authors

  • Rose Said Tishreen University
  • Norma Abbas

Abstract

Background: The Prothrombin Time (PT) assay is the most common test performed in hemostasis laboratories, often converted to an international normalized ratio (INR) to monitor anticoagulant therapy using vitamin K antagonists (VKAs), such as warfarin. Although the INR is meant to standardize PT values by taking into consideration the reagent and instrument variability; substantial inter-laboratory variation in INRs still exists and suggests that this can be further improved. This paper describes two methods of INR correction, one  (Favaloro method) based on improving the accuracy of the main components of the INR (MNPT/ISI), using normal and pathological samples from VKA-stabilized patients, and the other (Chandrshekar method) aims to bypass the ISI and finds a direct relationship between the INR and PT, using normal and pathological random samples that are not limited to patients stabilized on VKAs, i.e., prolonged PT samples are used regardless of the causal diagnosis

Purpose: A practical comparison of two simplified methods of local correction of the international normalized ratio (INR) applicable in Tishreen University Hospital.

Methods: The final study sample included 700 patients, 550 had a prolonged PT and 150 had a normal PT. Some of the latter was used to apply the methods used in this research, and the remaining section was used to calculate the MNPT for the various reagents,

Results:  In both methods, the difference between INRs i.e. (observed INR – corrected INR) decreased by increasing the number of samples (a more accurate correction for INR). By comparing the two methods, we found that the difference between the INRs was less using Chandrshekar method than using Favaloro method with statistical significance, indicating that, the Chandrshekar method is more accurate and easier to correct. We also noted that changing the material from the device company leads to significant differences between the INRs that requires correction.

Conclusion: Two methods are applicable in a large medical center such as Tishreen University Hospital, so that the appropriate method is chosen as per the working conditions according to the available capabilities of the used reagents and devices

Author Biographies

Rose Said, Tishreen University

Assistant Professor, Faculty of Human Medicine

Norma Abbas

Postgraduate Student, Faculty of Human Medicine

Downloads

Published

2022-03-29

How to Cite

1.
سعيد ر, عباس ن. Simplified methods for local correction of system international normalized ratio. Tuj-hlth [Internet]. 2022Mar.29 [cited 2024Nov.24];44(1):189-207. Available from: https://journal.tishreen.edu.sy/index.php/hlthscnc/article/view/12015

Issue

Vol. 44 No. 1 (2022): Tishreen University Journal for Research and Scientific Studies - Health Sciences Series

Section

Master student researches

License

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

The authors retain the copyright and grant the right to publish in the magazine for the first time with the transfer of the commercial right to Tishreen University Journal for Research and Scientific Studies - Health Sciences Series

 Under a CC BY- NC-SA 04 license that allows others to share the work with of the work's authorship and initial publication in this journal. Authors can use a copy of their articles in their scientific activity, and on their scientific websites, provided that the place of publication is indicted in  Tishreen University Journal for Research and Scientific Studies - Health Sciences Series   .  The Readers have the right to send, print and subscribe to the initial version of the article, and the title of  Tishreen University Journal for Research and Scientific Studies - Health Sciences Series  Publisher

journal uses a CC BY-NC-SA license which mean

You are free to:

  • Adapt — remix, transform, and build upon the material
  •  
  • The licensor cannot revoke these freedoms as long as you follow the license terms.

 

  • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • NonCommercial — You may not use the material for commercial purposes.
  • ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
  • No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.