When a bleed occurred, it was assumed that aPCC was used to treat the bleed at a dose of 85 IU kg−1. The model assumed 1.3 infusions were necessary to stop minor/moderate bleeds. Again, major bleeds were assumed to require hospitalization. Patients on ITI were assumed to incur bleeds similarly to patients receiving on-demand therapy. Once tolerized, Wnt antagonist the frequency of bleeds was assumed to be the same as that for patients on prophylaxis with bypassing agents for minor/moderate bleeds, and major bleeds were assumed to require
hospitalization [48-51]. With regard to response to ITI, at the start of ITI, 59.7% and 40.3% of patients were assumed to be good risk (BU < 10) or poor risk (BU ≥ 10) respectively. The assumed response to primary ITI was 83.1% and 50.0% in good- or poor-risk patients, respectively, and the response to secondary ITI was assumed to be 73.7% (risk not stratified) [12, 13]. Patients with haemophilia currently have a life expectancy approaching PLX4032 mouse that of people without the condition, mainly due to effective treatment of their disease. For the purpose of the model, we assumed the same life expectancy. Soucie
and colleagues estimated an increase in mortality due to inhibitors of 1.6 (95% CI: 0.8, 3.0) . Walsh et al. have estimated the odds of death to be 70% higher [OR 1.7 (95% CI: 1.2, 2.4)] in patients with inhibitors than in those without inhibitors (P < 0.01) . In the current model, preference is made for relative risk vs. odds; the model thus assumes a 1.6-fold increase in mortality due to inhibitors. Table 4 presents costs associated with drug acquisition and other related costs, as well as frequency data for inhibitor monitoring [54-58]. Utility weights represent the preference of being in a health state or avoiding certain events at a particular time. Utility weights range from 0 (death) to 1 (perfect health) and, combined with time, are used to calculate
quality-adjusted life-years (QALYs). Values used in the current decision analytic model were derived from Noone and colleagues who administered the EQ5D health survey in patients with haemophilia . Utilities for patients without inhibitors receiving on-demand or prophylactic treatment were 0.62 and 0.87 respectively. Patients with inhibitors were reported to have a utility of 0.79. learn more A patient with inhibitors while on prophylaxis was estimated to have a utility of 0.68 (assumed to be multiplicative). For each of the three treatment strategies, the model calculated drug and hospitalization costs, life-years, QALYs and bleeding events. Preliminary results from the model, over the lifetime of patients, are shown in Table 5. In this theoretical model, compared with on-demand or prophylactic treatment, ITI was associated with lower drug and hospitalization costs, longer projected life expectancy, higher QALYs and fewer projected bleeding events.