Method: To apply VOI methods, several parameters such as disease incidence, trial enrollment fraction, time horizon for the decision, costs and threshold values to avoid arthropathy were defined. Two baseline threshold values (willingness to pay) for avoiding arthropathy – $200,000 and $400,000 – were selected for comparing the treatment strategies.
Result: For threshold values < $200,000 OD had a higher estimated net benefit than either prophylaxis strategy. For threshold values > $400,000 prophylaxis strategies had higher estimated net benefit. At a threshold value of $200,000 OD was superior to both AP and TP. At a threshold value of $400,000, both prophylaxis strategies were superior to OD; however, a new trial with 38 patients per arm was needed to compare AP and TP, yielding an expected net gain of over $17 million.
Conclusion: In health policy decision-making, the recommendation for the adoption of new health interventions is made on the basis of a positive expected incremental net benefit. However, in rare diseases often the evidence is scarce and insufficient for decision making. In considering the funding of new research and patient reimbursement in rare diseases, VOI methodology provides more relevant determinations of the value and costs of additional research. The results of this study can help in decision making for treatment strategies and in the planning of future studies for hemophilia and other rare diseases.