von Willebrand disease: proposing definitions for future research.

von Willebrand disease (VWD) is a common bleeding disorder, which affects 1 in 100 individuals based laboratory testing and at least 1 in 1000 individuals based on presence of abnormal bleeding.1,2 VWD was first described almost 100 years ago, and since the initial report, major in both diagnostic testing and treatment options have improved outcomes for patients living VWD; however, many patients still experience significant complications and barriers to treatment. underlying problem is the lack of consistent unified definitions. recent work developing evidence-based guidelines for VWD,3,4 it was noted that studies on VWD used varying definitions. For example, studies of von Willebrand factor (VWF) concentrates did not consistent definitions for major bleeding, studies on VWF prophylaxis did not use consistent of what constituted a prophylaxis regimen, and studies on desmopressin did not use definitions of desmopressin responsiveness. In addition, common bleeding conditions, as heavy menstrual bleeding (HMB) and postpartum hemorrhage are variably defined. Such in describing study regimens and endpoints hinder the ability to compare study and to advance treatment of patients with VWD. propose definitions for future use in VWD research to facilitate comparison of treatment options. definitions are based on the most common usage in the literature and endeavor to encompass the common situations in VWD. The proposed definitions were derived from existing literature and at the first in-person meetings of the guideline panels. Group members made amendments, the consensus document was circulated to the group. All authors approved the final document.