Outcome in moderate haemophilia.

Background: Moderate haemophilia is the rarest form of haemophilia. This study aims to assess short- and long-term outcome, including its association with treatment, in patients with moderate haemophilia.

Methods: Seventy-five patients with moderate haemophilia (1-5% factor VIII/ factor IX activity), without a history of inhibitors, treated at the van Creveldkliniek, Utrecht (NL) were included in the study. Life-long data on bleeding and treatment were collected. Joints were evaluated using the Haemophilia Joint Health Score. Adults completed questionnaires on activity (HAL) and quality of life (SF-36, EQ5D).

Results: The median age of the patients was 37 years (IQR 23-52 years) and haemophilia A was diagnosed in 89%. Bleeding frequency was low: the median annual bleeding rate was 2.0 bleeds/ year (IQR 0.8-3.7 bleeds/year), including a median of 0 joint bleeds/year (IQR 0.8-3.7 bleeds/year). Joint function was good: 82% scored<10 out of 126 points of the Haemophilia Joint Health Score (HJHS). Nevertheless, 29% of patients with moderate haemophilia had a history of prophylaxis, because of a high bleeding frequency. Median age at first joint bleed was 4.8 years (IQR 3.5-8.5). Use of prophylaxis was more associated with age at first joint bleed (P<0.01) than with baseline factor activity (P=0.12). Most patients (52%) who suffered their first joint bleed before the age of 5 years required prophylaxis later in life.

Conclusions: The majority of patients with moderate haemophilia have few bleeds and complications; however, a considerable subset of patients with a more severe bleeding pattern need prophylactic treatment. These latter patients may be identified by the onset of joint bleeding before the age of 5 years.