Weaknesses in the classification criteria for antithrombotic-related major bleeding events

Charles Lagor; C. Gregory Elliott; Gregory J. Stoddard; Peter J. Haug

doi:10.1160/TH05-02-0138

Thrombosis and Haemostasis, Table of Contents

Thromb Haemost 2005; 94(05): 997-1003
DOI: 10.1160/TH05-02-0138

Blood Coagulation, Fibrinolysis and Cellular Haemostasis

Schattauer GmbH

Weaknesses in the classification criteria for antithrombotic-related major bleeding events

Authors

Charles Lagor

¹Philips Research USA, Briarcliff Manor, New York, USA
C. Gregory Elliott

³Pulmonary Divisions and Departments of Medicine, LDS Hospital and the University of Utah School of Medicine, Salt Lake City, Utah, USA
Gregory J. Stoddard

⁴Division of Clinical Epidemiology, University of Utah School of Medicine, Salt Lake City, Utah, USA
Peter J. Haug

²Department of Medical Informatics

Abstract

Summary

We asked two physicians to review the medical records (electronic and paper) of 100 patients on antithrombotics. The physicians used published classification criteria to identify all of the bleeding events that the patients experienced. The goal of the review was to investigate whether the physicians would identify the same antithrombotic related major bleeding events (ARMBEs) for each patient. The correct identification and classification of multiple bleeding events is a prerequisite for studies of antithrombotic treatment practices during hospitalization that predispose patients to ARMBEs. In addition, we were interested in the reasons for disagreement between the physicians, so that we could find ways of improving their agreement. The reviewers identified 299 bleeding events for the 100 patients. They disagreed on whether 29 of the events represented an ARMBE occurring during hospitalization. With a kappa statistic of 0.49 (95% confidence interval, 0.31 to 0.66) the agreement was moderate. The reviewers most often disagreed either because they misinterpreted the data (12 events) or because the classification criteria for ARMBEs were not explicit enough (9 events). Disagreement took two main forms: either the reviewers disagreed on ARMBEs by not identifying the same bleeds (11 events) or by not applying the severity criteria appropriately (7 events). Because the main type of disagreement was not identifying the same bleeds, a study investigating the antithrombotic treatment practices that predispose patients to ARMBEs would be threatened. We therefore proposed supplementing the existing classification criteria with additional rules to avoid ambiguities in patients with multiple events.

Keywords

Clinical/epidemiological studies - clinical trials: antiplatelet drugs - clinical trials:heparins / LMWH - clinical trials:oral anticoagulants

Full Text

References

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