Association between ABO blood group with FVIII half-life, VWF:Ag, and VWFpp/VWF:Ag. Influence of ABO blood group on FVIII half-life (A), VWF:Ag (B), and VWFpp/VWF:Ag (C). Statistical significance was assessed by the Mann-Whitney U test. Horizontal lines indicate mean ± standard error. (D) Influence of ABO blood group on the association between VWF:Ag and FVIII half-life was assessed by linear regression analysis. The slope for type O (m = 0.0428, P = .0112) and type non-O (m = 0.0809, P < .0001) are significantly different from 0 (null hypothesis) but not from each other (P = .1611). (E) Influence of ABO blood group on the association between VWFpp/VWF:Ag and FVIII half-life was assessed by linear regression analysis. The slope for type 0 (P = .6) is not significantly different from 0 (null hypothesis). The slope for type non-O (P = .002) is significantly different from 0 (null hypothesis) although the 2 slopes are not significantly different from each other (P = .1095). *P ≤ .05