Generation and optimization of the self-administered bleeding assessment tool and its validation as a screening test for von Willebrand disease.

INTRODUCTION/AIM: Our aim was to generate, optimize and validate a self-administered bleeding assessment tool (self-BAT) for von Willebrand disease (VWD).

METHODS: In Phase 1, medical terminology in the expert-administered International Society on Thrombosis and Haemostasis (ISTH)-BAT was converted into a Grade 4 reading level to produce the first version of the Self-BAT which was then optimized to ensure agreement with the ISTH-BAT. In Phase 2, the normal range of bleeding scores (BSs) was determined and test-retest reliability analysed. In Phase 3, the optimized Self-BAT was tested as a screening tool for first time referrals to the Haematology clinic.

RESULTS: Bleeding score from the final optimized version of the Self-BAT showed an excellent intra-class correlation coefficient (ICC) of 0.87 with ISTH-BAT BS in Phase 1. In Phase 2, the normal range of BSs for the optimized Self-BAT was determined to be 0 to +5 for females and 0 to +3 for males and excellent test-retest reliability was shown (ICC = 0.95). In Phase 3, we showed that a positive Self-BAT BS (≥6 for females, ≥4 for males) has a sensitivity of 78%, specificity of 23%, positive predictive value (PPV) of 0.15 and negative predictive value (NPV) of 0.86 for VWD; these figures improved when just the females were analysed; sensitivity of 100%, specificity of 21%, PPV = 0.17 and NPV = 1.0.

CONCLUSION: We show an optimized Self-BAT can generate comparable BS to the expert-administered ISTH-BAT and is a reliable, effective screening tool to incorporate into the assessment of individuals, particularly women, referred for a possible bleeding disorder.