title: Understanding patient preferences and willingness to pay for hemophilia therapies.
abstract: BACKGROUND
  Despite clearly improved clinical outcomes for prophylaxis compared to on-demand therapy, on average only 56% of patients diagnosed with severe hemophilia receive prophylactic factor replacement therapy in the US. Prophylaxis rates generally drop as patients transition from childhood to adulthood, partly due to patients becoming less adherent when they reach adulthood. Assessment of patient preferences is important because these are likely to translate into increased treatment satisfaction and adherence. In this study, we assessed preferences and willingness to pay (WTP) for on-demand, prophylaxis, and longer acting prophylaxis therapies in a sample of US hemophilia patients.
  
  
  METHODS
  Adult US hemophilia patients and caregivers (N=79) completed a discrete-choice survey that presented a series of trade-off questions, each including a pair of hypothetical treatment profiles. Using a mixed logit model for analysis, we compared the relative importance of five treatment characteristics: 1) out-of-pocket treatment costs (paid by patients), 2) factor dose adjustment, 3) treatment side effects, 4) availability of premixed factor, and 5) treatment effectiveness and dosing frequency. Based on these attribute estimates, we calculated patients' WTP.
  
  
  RESULTS
  Out-of-pocket treatment costs (P<0.001), side effects (P<0.001), and treatment effectiveness and dosing frequency (P<0.001) were found to be statistically significant in the model. Patients were willing to pay US $410 (95% confidence interval: $164-$656) out of pocket per month for thrice-weekly prophylaxis therapy compared to on-demand therapy and $360 (95% confidence interval: $145-$575) for a switch from thrice-weekly to once-weekly prophylaxis therapy.
  
  
  CONCLUSIONS
  Improvements in treatment effectiveness and dosing frequency, treatment side effects, and out-of-pocket costs per month were the greatest determinants of hemophilia treatment choice and WTP. The positive preferences and WTP for longer acting prophylactic therapies suggest that the uptake is likely to increase adherence, improving treatment outcomes. These preferences should also inform the Food and Drug Administration's assessment of new longer acting hemophilia therapies.
authors.affiliation: Department of Clinical Pharmacy, Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA, USA.
authors.forename: Shraddha S
authors.initials: SS
authors.lastname: Chaugule
authors.affiliation: Department of Clinical Pharmacy, Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA, USA.
authors.forename: Joel W
authors.initials: JW
authors.lastname: Hay
authors.affiliation: Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA.
authors.forename: Guy
authors.initials: G
authors.lastname: Young
keywords: hemophilia; patient; preferences; willingness to pay