Predictors of Bleeding Evaluation in Adult Hematologic Patients with Bleeding Tendencies
Patients with established bleeding disorders: The BePa verification study

Accurate diagnosis of a bleeding disorder is mandatory for implementation of
appropriate treatment. Lately, the market for haemostatic assays has been
overflooded with
new commercially available tests, so-called global haemostatic tests, with
unsupported
claims of predicting normal and abnormal haemostasis. Also the bleeding
assessment tool
(BAT) might be useful as a diagnostic tool for detection of patients with a
possible bleeding
disorder. Benefits of these *experimental* tests and the BAT could be more
accurate and
faster detection of bleeding disorders. The experimental tests could also
improve
management of patients with bleeding disorders who use prophylactic medication.
These
tests need validation in clinical practice.

To evaluate the diagnostic accuracy of the experimental tests to detect
bleeding disorders and to evaluate whether or not they can be used for
monitoring the effects of coagulant factor replacement therapy.

In this diagnostic validation study we want to evaluate if the experimental
tests and the bleeding assessment tool (BAT) are able to detect bleeding
disorder. We will
evaluate these tests in patients with established bleeding disorders. The
distribution of test
values from these patients will be compared with a distribution of reference
values from a
healthy population without bleeding disorders, available from the PANE study
(NL38767.068.11). Sensitivity and specificity of the experimental tests will be
estimated at
various cut-off values and results will be summarized in receiver operating
characteristic
(ROC) curves with corresponding area under the curve (AUC). Values of the
experimental in
patients with a bleeding disorder before and after planned medical intervention
will be used
to see if these tests are able to detect the differences in plasma factor
levels before and after
treatment.

Future benefits of the new tests could be more accurate and faster detection of
bleeding disorders and better management of patients with bleeding disorders
who use prophylactic medication. However, the participants cannot benefit yet,
because this study does not interfere with current clinical practice. The risks
associated with participation in this study are low. A venapuncture is
performed by skilled and experienced laboratory technicians. For the study,
only a small amount of blood, 60-78 ml is needed. Therefore no harm can be
expected. Blood withdrawal could result in a hematoma, but this is usually not
harmful. Bleedings from the blood withdrawal are usually negligible. In
patients with prophylactic factor substitution the blood withdrawl will be
planned in order not to interfere with their normal medication scedule.