Reliability and reproducibility of classification of children as "bleeders" versus "non-bleeders" using a questionnaire for significant mucocutaneous bleeding.

The diagnosis of type 1 von Willebrand disease (VWD), the most common inherited bleeding disorder in humans, is greatly dependent on an accurate diagnosis of significant mucocutaneous bleeding. In a previous study, the authors modified the criteria of the International Society on Thrombosis and Haemostasis for significant mucocutaneous bleeding to a format, the Hospital for Sick Children (HSC) criteria, that was more applicable to diagnose significant mucocutaneous bleeding in children. To assess the reliability and reproducibility of classification of subjects as "bleeders" versus "non-bleeders" using a questionnaire for significant mucocutaneous bleeding targeted to children, 39 subjects interviewed for a previous HSC VWD study were reinterviewed for the current study. The original bleeding classification was confirmed in 80% of subjects interviewed for a second time, indicating that this method of classification is reproducible (kappa = 0.65), with a "substantial" agreement among the investigators who reviewed the questionnaire responses (kappa = 0.71). The validity and utility of the HSC questionnaire for primary screening of children with suspected mucocutaneous bleeding disorders merits assessment in further clinical studies.