Generation and validation of the Condensed MCMDM-1VWD Bleeding Questionnaire for von Willebrand disease

Authors


Paula James, Room 2025 Etherington Hall, Queen’s University, Kingston, ON K7L 3N6, Canada.
Tel.: +1 613 533 2946; fax: +1 613 533 6855.
E-mail: jamesp@queensu.ca

Abstract

Summary. Background: Given the challenges involved in obtaining accurate bleeding histories, attempts at standardization have occurred and the value of quantifying hemorrhagic symptoms has been recognized. Patients/methods: An extensive validated bleeding questionnaire (MCMDM-1VWD) was condensed by eliminating all details that did not directly affect the bleeding score (BS) and the correlation between the two versions was tested. Additionally, the diagnostic utility of the condensed version was prospectively tested. Results: Data on 259 individuals who were administered the questionnaire are presented here; 217 being prospectively investigated for von Willebrand disease (VWD) (group 1) and 42 previously known to have type 1, 2 or 3 VWD (group 2). Of the 217 prospectively investigated, 35 had positive BS (≥4) and 182 had negative scores. Seven individuals (all with positive BS) had laboratory results consistent with type 1 VWD. This results in a sensitivity of 100% and a specificity of 87%. The positive predictive value is 0.20 and the negative predictive value is 1. The correlation between the full MCMDM-1VWD and condensed versions is excellent (Spearman’s 0.97, P < 0.001, linear regression r2 = 96.4). Inter-observer reliability for the condensed version is reasonable (Spearman’s 0.72, P < 0.001 and intra-class correlation coefficient 0.805, P < 0.001). There was a significant difference in BS between subtypes of VWD, with type 3 >> type 2 >> type 1 VWD (anovaP < 0.001). There is a strong inverse relationship between VWF:Ag level and BS (Spearman’s −0.411, P < 0.001). Conclusions: The Condensed MCMDM-1VWD Bleeding Questionnaire is an efficient, effective tool in the evaluation of patients for VWD.

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