Adherence to prophylaxis and bleeding outcome in haemophilia: a multicentre study

Prevention of bleeding and joint damage in severe haemophilia is dependent on adherence to prophylactic replacement therapy. The aim of this study was to assess adherence to prophylaxis, including associations with age, bleeding and clotting factor consumption (CFC). In three Dutch haemophilia centres, semi-structured interviews about adherence to prophylaxis in the previous 2weeks were conducted with patients or parents of a child with haemophilia. Patients were classified, according to pre-specified definitions, as adherent, sub-optimally adherent or non-adherent based on missing, timing, and dose of infusions. Association of annual bleeding rates, mean CFC, person performing the infusion (parents verus patients) with adherence categories were analysed. Overall, 241 patients with haemophilia using prophylaxis were studied. Parents were more adherent (66%; n=48/73) than patients (43%; n=72/168). Sub-optimal adherence occurred in 29% of parents and 37% of patients and was characterized by changes in timing of infusion (mostly from morning to evening), while missing <6% of infusions. Non-adherence occurred less often: in 5% of parents and 20% of patients. Reduced adherence was associated with lower CFC, but not with joint bleeding. In conclusion, non-adherence in haemophilia was relatively rare, yet 1/3 of patients struggled to administer prophylaxis at the appropriate time of day.