Preference-based valuation of treatment attributes in haemophilia A using web survey

Abstract

Introduction: Clinical trials have shown promising results for extended half-life factor VIII concentrates but little is known about individuals' valuation of haemophilia treatment attributes. Aim: To assess patient/caregiver and population valuation of treatment attributes of prophylactic regimens for people with severe haemophilia A. Methods: Members ≥16 years of the Swedish Haemophilia Society (FBIS) and of a web-panel representative of the Swedish population were invited to participate in a web-survey investigating preferences for haemophilia treatment attributes using the Time Trade-Off methodology which ranks health states on a scale 0 (dead) to 1 (full health). All respondents assessed the same four treatment scenarios for severe haemophilia A, each described by three stylized attributes: injection interval (every 2nd or 5th day); participation in physical activity (Y/N); annual risk of bleed (1-2 or 5-6 bleeds). Results: The survey had 1657 respondents (68% complete responses; 184/1233 from FBIS/web-panel gave informed consent; mean age 52 years, 51% men). Respondents from FBIS and from the web-panel had the same preference ranking of the four treatment scenarios, but members of FBIS consistently rated significantly higher health utilities; range 0.67-0.73 vs 0.54-0.60. Participation in physical activity implied +0.023 (95% confidence interval 0.015-0.030); a longer injection interval implied +0.038 (0.03; 0.45); and fewer bleeds implied +0.022 (0.015-0.029) utility points. Conclusions: Patient/caregiver and population preferences indicate that treatment attributes such as frequency of injections and the possibility of participating in physical activity are important attributes impacting quality of life in addition to the control and prevention of bleeding episodes