Table 1.
Assumptions used in the model
| Patient weight of 63 kg, based on the average weight for men and women calculated from the British National Formulary and varied within the sensitivity analysis to account for a spectrum of child and adult weights [56]. This weight is consistent with the average patient weight from US DFP patient registries of 62 kg [57] |
| Dosing was assumed to be from the mid-range of the product SPCs, based on the input of two consultant haematologists and one consultant nephrologist. The impact of alternative dosing was considered in sensitivity analysis |
| Patients who developed cardiac disease were conservatively assumed to have NYHA grade I disease and no incremental costs were considered |
| The cost of managing thalassaemia was assumed to be the same for all treatment regimens and was therefore not accounted for in the model |
| All iron chelation regimens are assumed to have an equivalent effect on SFC and LIC. Given the difficulty in correlating these outcomes with morbidity and mortality, this assumption was not varied in sensitivity analysis |
| Due to a lack of data regarding the efficacy of DFX in cardiac morbidity and mortality, it was assumed that the rates of cardiac events (including deaths with DFX) are the same as for DFO. Data on cardiac T2* for DFO and DFX were used as a proxy to establish equivalence of the treatments |
| As morbidity and mortality data are taken from separate studies, the risk of death in both alive health states was considered to be equal |
| The utility value for DFP administration was assumed to be equal to that for DFX based on oral administration dosing regimens |
| While compliance is expected to be greater with oral treatments than with SC infusion, RCTs have found no difference [19, 21]. In the absence of robust data indicating a difference between treatments, compliance was assumed to be comparable across all regimens |
DFO desferrioxamine, DFP deferiprone, DFX deferasirox, LIC liver iron concentration, NYHA New York Heart Association, RCT randomised controlled trial, SC subcutaneous, SFC serum ferritin concentration, SPC summary of product characteristics