This volume contains all relevant information discussed in a Workshop on thromboplastin calibration held in Leiden, The Netherlands on July 1, 1983. The Workshop was an initiative of the Dutch foundation for a Reference Laboratory for Anticoagulant Control (RELAC) and it was organized by the Boerhaave Committee for postgraduate teaching of the Faculty of Medicine of the University of Leiden. The Workshop was held under the auspices of five organizations i. e. the European Community Bureau of Refer ence (BCR) , the European Committee for Clinical Laboratory Standards (ECCLS), the International Association of Biological Standardization (lABS), the International Committee for Standar dization in Haematology (ICSH), ·and the International Committee on Thrombosis and Haemostasis (ICTH). The aim of the Workshop was to discuss and develop a method for calibration of reagents, i. e. thromboplastins and/or plasmas used for the prothrombin time. During the Workshop three recent thromboplastin calibration studies were discussed, the results of which are presented in chapters 4, 7 and 9. These studies were carried out on the basis of a new calibration model developed by experts working with BCR and WHO. The usefulness of this model and the standardization system based on it is the leading thread running through this volume. Statisticians and clinicians discuss the results from a scientific point of view. Thromboplastin manufacturers, for whom especially the use of the model and the system is intended, discuss the matter also from an economic and legal point of view.
Table of Contents1. Introduction.- 2. General Aspects of Thromboplastin Calibration.- 3. Orthogonal Regression Equation.- 4. The European Community Bureau of Reference Calibration Study.- 5. A Statistician’s Independent Evaluation.- 6. Critical Remarks from a Clinician’s Point of View.- Discussion.- 7. The Manufacturers’ Calibration Study.- 8. INR Ranges and Targets for Oral Anticoagulation to be Effective and Safe.- Discussion.- 9. The British System of Oral Anticoagulant Control and its Relation with the W.H.O. System: Calibration of the Proposed Second W.H.O. International Reference Thromboplastin (BCT/253).- 10. Anomalies of Thromboplastin Nomenclature.- 11. Comparison of a Highly Sensitive Rabbit Brain Thromboplastin, Dade Thromboplastin FS, with a Human Brain Thromboplastin, Manchester Comparative Thromboplastin.- Comment on Dr. Spaethe’s contribution.- 12. Proficiency Testing and Standardization of Prothrombin Time Potential Use of Thromboplastin Calibration in the United States.- 13. The Relationship between the International Normalized Ratio and the Coumarin-Induced Coagulation Defect.- Discussion.- 14. Joint ICTH/ICSH Proposed Policy Statement with Respect to Reporting the Prothrombin Time in Oral Anticoagulant Control.- Discussion.- 15. A Manufacturer’s View of Thromboplastin Calibration (I).- 16. A Manufacturer’s View of Thromboplastin Calibration (II).