A multicenter prospective observational cohort study to improve diagnostic yield and clinical management of persons with a Bleeding Disorder of Unknown Cause (BDUC-iN study protocol)

BACKGROUND: In half of individuals referred for evaluation of bleeding symptoms, no hemostatic defect is identified with current standard hemostasis tests. These individuals are classified as having a bleeding disorder of unknown cause (BDUC). The pathophysiological mechanisms underlying the bleeding tendency in BDUC are unknown. The absence of a clear, molecular diagnosis leads to significant challenges for healthcare professionals in terms of diagnostics and clinical management, as well as insecurity in patients and caregivers.

OBJECTIVES: The BDUC in the Netherlands (BDUC-iN) study aims to improve diagnostic accuracy and optimize treatment strategies among individuals with BDUC by evaluating healthcare delivery, patient outcomes, health-related quality of life and by identifying underlying pathophysiological mechanisms of the bleeding tendency.

METHODS: This is a multicenter prospective observational cohort study aiming to include 500 persons with BDUC. Diagnostic, therapeutic and fundamental research questions are organized in dedicated work packages.

CONCLUSIONS: Clinical data is collected longitudinally over a 10-year follow-up period. Quality of life and quality of care are assessed using validated questionnaires. Advanced hemostasis tests and proteogenomics are performed to characterize bleeding phenotypes and potentially identify hemostatic defects.Conclusions: The BDUC-iN study applies a structured approach to address current challenges in BDUC. It aims to improve clinical management and patient outcomes by attaining diagnostic accuracy and developing pathophysiologically-based treatment strategies. In turn, this will support the development of (evidence-based) clinical guidelines and shape future research initiatives in BDUC.