Treatment for life for severe Haemophilia A: a cost-utility model

Abstract

Introduction. Prophylaxis has been established as the treatment of choice in children with haemophilia and its continuation into the adult years has been shown to decrease morbidity throughout life. The cost of factor therapy has made the option questionable in costeffectiveness studies. Aim. The role of prophylaxis in pharmacokinetic dosage and tolerisation against inhibitor formation were used to model the cost-utility of prophylaxis versus on-demand (OD) therapy over a lifetime horizon in severe haemophilia A. Methods. Commercial software (TreeAgeTM) was used to construct a Markov model with 80 cycles of one year each. The model was populated with variables for costs and effectiveness for haemophilia outcomes including joint and soft tissue bleeds, inhibitors and dosage. Key inputs into the model which differed from previous exercises included the use of pharmacokinetic dosage and effect of prophylaxis on the probability of developing inhibitors.The model was applied to a single provider national health system exemplified by the United Kingdom’s National Health Service and a third party provider in the United States. The incremental cost effectiveness ratio was (ICER) was estimated and compared to threshold values used by payer agencies to guide reimbursement decisions. A cost per quality adjusted life year (QALY) was also estimated for Sweden. Results. Applying a bidiurnal dosage regimen and using the early tolerisation protocol of Kurnik et al (Haemophilia. 2010;16(2):256–62),prophylaxis was shown to be more effective and less costly (dominant) relative to OD treatment in the UK. In the USA, the model resulted in an ICER $68,000, which is within the range of treatments reimbursed by third party payers in that country.In Sweden, a cost/QALY of SEK 1.1 million was also within the range of reimbursed treatments in that country, and prophylaxis was dominant over OD treatment when daily dosage was applied. Sensitivity analysis showed that dosage and treatment-induced inhibitor incidence were the most important variables in the model. Conclusion. Subject to continuing clinical evidence of the effectiveness of pharmacokinetic dosage and the role of prophylaxis in decreasing inhibitor incidence, treatment for life with prophylaxis is a cost-effective therapy, using current criteria for the reimbursement of health care technologies in a number of countries.