The current recommended diagnostic algorithm for VWD. Platelet-dependent VWF activity, VWF:GPIbM (GPIb binding assay for VWF using recombinant mutated GPIb, no ristocetin) or VWF:GPIbR (GPIb binding assay for VWF using recombinant GPIb and ristocetin). ∗Intermediate/high probability of VWD (ie, family history), adult males and children referred to a hematologist. CBC, complete blood count; DDAVP, desmopressin (1-deamino-8-D-arginine vasopressin); PT, prothrombin time; PTT, partial thromboplastin time; R/O, rule out. Adapted from James et al.³⁰