VWF and Stroke: The age- and sex-adjusted relative risk was nominal 1.27 (confidence interval [CI], 0.95–1.72; for every unit increase in vWF-antigen level on a logarithmic scale), but this was not statistically significant.55In the same study cohort after a prolonged follow-up period of 17 years, the number of strokes in the population quadrupled and then the association of stroke risk and vWF antigen level became statistically significant, with the hazard ratio (HR) adjusted for age and sex of 1.42 (CI, 1.09–1.85) comparing top versus bottom tertile of vWF antigen.56