Country-level prediction of blood type distribution in hemophilia A in support of factor VIII consumption

Authors: Chelle, P; Hirniak, S; Hajducek, D; Iorio, A; Edginton, A

Affiliations: School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada. School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada. Department of Health Research Methods, Evidence and Impact and Dept of Medicine, McMaster University, Ontario, Canada.

Publication: Res Pract Thromb Haemost ; 2026; 10. 103356

ABSTRACT: BACKGROUND: Hemophilia A is an inherited bleeding disorder resulting from a lack of factor (F)VIII. Patients with blood type O show faster decay in their FVIII pharmacokinetics and may require higher usage of factor concentrate. Although country-level blood type distribution among persons with hemophilia A is not well characterized, its alignment with the general population may offer a useful basis for prediction. OBJECTIVES: This study compared FVIII usage across blood types and assessed whether the distribution of blood types differs between general population and persons with hemophilia A. METHODS: Data were extracted from the WAPPS-Hemo research database for the hemophilia A cohort and from an online source for the general population. Factor VIII pharmacokinetics and usage differences were assessed using analysis of variance. Poisson log-linear regression models described crosscountry counts of blood types. Congruence between blood type distributions of persons with hemophilia A and general populations was assessed by likelihood ratio test. RESULTS: Factor VIII pharmacokinetics and usage was significantly different in patients with blood type O. Likelihood ratio test comparison showed no significant difference between both cohorts, with Poisson regression describing reasonably well the count and distribution across blood types. CONCLUSION: Patients with blood type O were found to require more FVIII on average. Predicting blood type distributions in persons with hemophilia A is enabled by their statistical similarity to the general population, potentially supporting country-level management of FVIII accessibility. Since South and Latin American countries showed a higher blood type O incidence, persons with hemophilia A from these populations may require a higher FVIII usage.