von Willebrand disease: proposing definitions for future research.
Nathan T. Connell, Paula James, Romina Brignardello‐Petersen, Rezan A. Kadir, Barbara Ameer, Alice Arapshian, Susie Couper, Jorge Di Paola, Jeroen Eikenboom, Nicolas Giraud, Jean M. Grow, Sandra L. Haberichter, Vicki Jacobs-Pratt, Barbara A. Konkle, Peter A. Kouides, Michael Laffan, Michelle Lavin, Frank W.G. Leebeek, Claire McLintock, Simon McRae, Robert R. Montgomery, Sarah H. O’Brien, James S. O’Donnell, Margareth C. Ozelo, Nikole Scappe, Robert F. Sidonio, Alberto Tosetto, Angela C. Weyand, Mohamad A. Kalot, Nedaa Husainat, Reem A. Mustafa, Veronica H. Flood
Abstract
von Willebrand disease (VWD) is a common bleeding disorder, which affects 1 in 100 individuals based\non laboratory testing and at least 1 in 1000 individuals based on presence of abnormal bleeding\nsymptoms.1,2 VWD was first described almost 100 years ago, and since the initial report, major\nadvances in both diagnostic testing and treatment options have improved outcomes for patients living\nwith VWD; however, many patients still experience significant complications and barriers to treatment.\nAn underlying problem is the lack of consistent unified definitions.\nIn recent work developing evidence-based guidelines for VWD,3,4 it was noted that studies on VWD\noften used varying definitions. For example, studies of von Willebrand factor (VWF) concentrates did not\nhave consistent definitions for major bleeding, studies on VWF prophylaxis did not use consistent\ndefinitions of what constituted a prophylaxis regimen, and studies on desmopressin did not use\nconsistent definitions of desmopressin responsiveness. In addition, common bleeding conditions,\nsuch as heavy menstrual bleeding (HMB) and postpartum hemorrhage are variably defined. Such\ninconsistencies in describing study regimens and endpoints hinder the ability to compare study\noutcomes and to advance treatment of patients with VWD.\nWe propose definitions for future use in VWD research to facilitate comparison of treatment options.\nThese definitions are based on the most common usage in the literature and endeavor to encompass the\nmost common situations in VWD. The proposed definitions were derived from existing literature and\ndiscussed at the first in-person meetings of the guideline panels. Group members made amendments,\nand the consensus document was circulated to the group. All authors approved the final document.