Thromb Haemost 1997; 78(04): 1189-1192
DOI: 10.1055/s-0038-1657713
Rapid Communication
Schattauer GmbH Stuttgart

Bleeding Classification in Clinical Trials: Observer Variability and Clinical Relevance

Yvonne P Graafsma
1   The Department of Clinical Epidemiology and Biostatistics, University Hospital Leiden, The Netherlands
,
Martin H Prins
1   The Department of Clinical Epidemiology and Biostatistics, University Hospital Leiden, The Netherlands
,
Anthonie W A Lensing
2   The Department of Neurology, University Hospital Leiden, The Netherlands
,
Rob J de Haan
1   The Department of Clinical Epidemiology and Biostatistics, University Hospital Leiden, The Netherlands
,
Menno V Huisman
4   The Academic Medical Center, University of Amsterdam. Department of Internal Medicine, University Hospital Leiden, The Netherlands
,
Harry R Büller
3   The Center for Hemostasis, Thrombosis, Atherosclerosis, and Inflammation Research, University Hospital Leiden, The Netherlands
› Author Affiliations
Further Information

Publication History

Received 15 1997

Accepted after revision 13 June 1997

Publication Date:
12 July 2018 (online)

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Summary

To evaluate the bleeding classification in a recent trial on venous thrombosis treatment, a selection of reported bleeding episodes was adjudicated twice by an independent committee and graded by the treating physician and independent clinical experts on the clinical severity and impact on the patient’s life.

The kappa values for the dichotomy major bleeding versus minor or no bleeding were 0.79 (95% CI, 0.57-1.0) for the agreement between the two members of the adjudication committee and 0.77 (95% CI, 0.52-1.0) for the agreement between both adjudication sessions. The kappa values for the dichotomy major or minor bleeding versus no bleeding were 0.42 and 0.44. The weighted kappa values for the agreement between the treating physician and the independent experts were 0.76 for the Clinical severity and 0.79 for the impact on the patient’s life (95% CI, 0.63-0.88 and 0.70-0.89). The association between the adjudication result expressed as major bleeding or minor or no bleeding and the Clinical grading by the treating physician resulted in an ROC curve with an area under the curve of 0.98 for the Clinical severity and 0.99 for the impact on the patient’s life. The dichotomy major or minor bleeding versus no bleeding resulted in areas under the curve of 0.70 and 0.66.

In conCIusion, the applied criteria for major bleeding are reproducible and Clinically relevant. The criteria for minor bleeding are not reproducible and are less associated with the observed Clinical relevance.