Canadian Hemophilia Prophylaxis Study

Moderate Term Musculoskeletal Outcomes With Escalating Dose Prophylaxis: the Canadian Hemophilia Prophylaxis Study Follow-up Study

Primary prophylaxis given less frequently initially, with the infusion frequency increased if needed (Escalating Dose Prophylaxis), is likely to be less expensive and associated with fewer complications than standard prophylaxis while reducing disability to a greater degree than intermittent therapy.

There are 2 specific study objectives. The first is to estimate the incidence of target joint bleeding in patients with severe hemophilia A treated (for primary prophylaxis) with Escalating Dose Prophylactic factor replacement. The second objective is to obtain accurate estimates of the direct and indirect costs associated with this protocol for use in a cost-effectiveness model (comparing Escalating Dose with standard prophylaxis and with intermittent therapy).

Inclusion Criteria:

• Severe hemophilia A (factor level less than 2%).
• Age greater than 1 year and less than or equal to 2.5 years.
• Normal joints using the World Federation of Hemophilia orthopedic scale.
• Normal radiographs of joints in which bleeding has occurred using the World Federation of Hemophilia radiographic scale.
• Platelet count of > 150,000.
• Informed consent to participate.

Exclusion Criteria:

• Three or more clinically determined bleeds into any single elbow, knee or ankle.
• Presence or past history of a circulating inhibitor (level ≥ 0.5 Bethesda Units).
• Family judged to be non-compliant by the local hemophilia clinic director.
• Competing risk (symptomatic HIV infection, juvenile rheumatoid arthritis, metabolic bone disease, or other diseases known to cause or mimic arthritis.)