Haemophiliacs with factor VIII inhibitors in Finland: prevalence, incidence and outcome.

Twenty-five of the 139 Finnish patients (18.0%) with severe haemophilia A alive in 1960 or born later have or have had an inhibitor against factor VIII. 19 of the 110 patients alive have an inhibitor and the current prevalence is 17.3%. The incidence of new inhibitors was 10.3 per thousand patient years for the observation period starting from 1960, median 16 years. The age dependent cumulative risk of developing an inhibitor was 22% at the age of 10. There have been no deaths from bleeding since 1976, which has resulted in a marked decrease in mortality. The annual death rate of patients with inhibitors was 5.8 per thousand years of life in 1980-89 compared to 41.7 in the previous decade. The recent progress in the modalities for treatment of bleedings has markedly improved the outcome of patients with factor VIII inhibitors.