A review of variables affecting PTs/INRs

Area of Science:

• Clinical chemistry
• Hematology
• Medical diagnostics

Background:

• Prothrombin time (PT) is a standard test for monitoring oral anticoagulant therapy.
• Variability in thromboplastin reagents and automated analyzers complicates PT standardization.

Purpose of the Study:

• To highlight the need for standardization in prothrombin time monitoring.
• To address challenges posed by diverse thromboplastin brands and automated systems.

Main Methods:

• Review of current practices in oral anticoagulant therapy monitoring.
• Analysis of factors influencing prothrombin time variability.

Main Results:

• The increasing number of thromboplastin brands with varying International Sensitivity Index (ISI) values contributes to monitoring inconsistencies.
• Widespread use of automated coagulation analyzers further necessitates standardized protocols.

Conclusions:

• Standardization of prothrombin time monitoring is essential for patient safety and therapeutic efficacy.
• Harmonizing methods and reagents will improve the reliability of anticoagulant therapy management.