VWF:GPIbM/VWF:Ag ratios in all patients with low VWF. (A) VWF:GPIbM and VWF:Ag in the total low VWF cohort (n = 150) at the time of inclusion in the study. The orange area indicates patients with a VWF:GPIbM/VWF:Ag ratio of <0.7. (B) Significant variability was observed in the VWF:GPIbM/VWF:Ag ratio among patients with low VWF. (C) Overall, 25 of 150 (16.7%) patients with low VWF had VWF:GPIbM/VWF:Ag ratios of <0.7. (D) The ISTH-BAT bleeding scores in patients with VWF:GPIbM/VWF:Ag ratios ≥0.7 and <0.7. The P value was determined using an independent t test.