Haemophilia and related disorders are inherited conditions that result in patients experiencing excessive bleeding. Treatment is by replacement of the missing clotting factor with infused factor concentrate, use of other blood components, desmopressin, non-factor therapies or gene therapy.

In the past, infections transmitted by contaminated clotting factor concentrates resulted in many patients with haemophilia becoming infected with HIV and hepatitis C viruses. Although current concentrates are safer in terms of infections, continued close surveillance is required. Other adverse events are the development of antibodies to factor concentrates (inhibitors), allergic events, thrombotic events, and other events.

Because haemophilia and other inherited bleeding disorders are rare and therefore adverse events related to their treatment are also rare, it is necessary to follow a large number of patients in order to identify and define the risk of developing these complications after treatment with the different products. This is what EUHASS has been designed to do by creating a prospective adverse event reporting system for Europe.