Influence of Age, Sex and Blood Groups on 15 Blood Coagulation Laboratory Variables in a Reference Material Composed of 80 Blood Donors

15 blood coagulation and fibrinolysis variables were determined in 80 healthy blood donors. Males were shown to have significantly higher levels of factor VII and factor X, and in subjects with blood group O significantly lower levels of VIIIR:AG were observed. In individuals with blood group O a skewed distribution of VIIIR:AG suggested a mixed population of this antigenic determinant. No significant correlation (r less than 0.36) was found between age and any of the laboratory variables.