The average amount of factor IX concentrate used per haemophilia B patient increased to 26,769 units at thr UK Haemophilia Centres. Linked evidence CBLA0001612 - Annual Returns for Haemophilia Centres summary 1981 - 01 Sep 1982 Chronology Information Date: 1 January 1981 Chapter/issue Haemophilia Centres: Policies and Practice