Reported prevalence of von Willebrand disease worldwide in relation to income classification

Introduction: The diagnosis of von Willebrand disease (VWD) is complex and challenging, especially when diagnostic resources are limited. This results in a lack of consistency in identifying and reporting the number of people with VWD and variations in the VWD prevalence worldwide. Aim: To analyze the reported prevalence of VWD worldwide in relation to income classification. Methods: Data on the VWD prevalence from the World Federation of Hemophilia Annual Global Survey, national registries of Australia, Canada, and the United Kingdom, and the literature were analysed. The income level of each country was classified according to the World Bank. Results: The mean VWD prevalence worldwide was 25.6 per million people. The VWD prevalence for high-income countries (HIC) of 60.3 per million people was significantly greater (p <.01) than upper middle (12.6), lower middle (2.5) and low (1.1) income countries. The type 3 VWD prevalence for HIC of 3.3 per million people was significantly greater (p <.01) than lower middle (1.3) and low income (0.7) countries. The reported VWD prevalence was greater among females than males. Conclusion: The reported VWD prevalence varied considerably across and within income classifications. The variability of type 3 VWD prevalence was less than the VWD prevalence (all types). The variability in detection and diagnosis of type 1 VWD presents a challenge in forming a consistent prevalence value across countries and income classifications.