Estimates of utility weights in hemophilia: implications for cost-utility analysis of clotting factor prophylaxis.

Estimates of preference-weighted health outcomes or health state utilities are needed to assess improvements in health in terms of quality-adjusted life-years. Gains in quality-adjusted life-years are used to assess the cost-effectiveness of prophylactic use of clotting factor compared with on-demand treatment among people with hemophilia, a congenital bleeding disorder. Published estimates of health utilities for people with hemophilia vary, contributing to uncertainty in the estimates of cost-effectiveness of prophylaxis. Challenges in estimating utility weights for the purpose of evaluating hemophilia treatment include selection bias in observational data, difficulty in adjusting for predictors of health-related quality of life and lack of preference-based data comparing adults with lifetime or primary prophylaxis versus no prophylaxis living within the same country and healthcare system.