Objective: Our objective was to generate, optimize, and validate a self-administered pediatric

bleeding questionnaire (Self-PBQ) as a screening tool for von Willebrand disease (VWD) in chil- dren referred to the hematology clinic for the first time.

The Self-PBQ was pretested in healthy children and in children with a confirmed diagnosis of type 1 VWD. Healthy children were defined as those self- or parent-identified as healthy, with no significant past medical history and taking no medications. They were recruited from Kingston, Ontario, using newspaper and school newsletter advertise- ments. Children with type 1 VWD were recruited from the Inherited

Bleeding Disorders Clinic of Southeastern Ontario. As in previous investigations,2,5,9 the study defined type 1 VWD by a von Willebrand factor antigen (VWF:Ag) and/or von Willebrand factor ristocetin cofactor activity (VWF:RCo) between 0.05 and 0.50 IU/mL on two occasions whenever possible, a RCo:Ag ratio >0.6, and a normal von Willebrand factor multimer profile. Type 1 VWD was chosen as the comparator group because it is the most common mucocutaneous bleeding disorder and the best studied bleeding disorder from the perspective of BATs.

The generation, validation, and optimization of the Self-PBQ was a multicenter effort involving six institutions (Kingston, Toronto, Ottawa, Vancouver, Calgary, and St. John’s) of the Canadian Pedi- atric Hemostasis and Thrombosis Network. Research Ethics Board approval was obtained from all participating institutions. All subjects were between the ages of 0 and 18 years. Written informed con- sent/assent was obtained from all caregivers/children.