Analytical approach:
This economic evaluation was based on a decision model that was developed to simulate the impact of the two chemotherapy regimens on the natural development of disease. The time horizon of the analysis was three years. The authors stated that the analysis was carried out from the perspective of the Italian National Health Service (NHS).
Effectiveness data:
The clinical data were obtained from a single study. Specifically, the evidence on treatment efficacy was derived from a large randomised controlled trial, the MinT study, which examined 410 eligible patients who received CHOP, and 413 who received R-CHOP. This trial provided the data on response rate at five months and at three years. Those patients who did not achieve a complete response at five months were assumed to have then received rescue therapy.
Monetary benefit and utility valuations:
None.
Measure of benefit:
Life-years (LYs) were the summary benefit measure used in the economic analysis. LYs were discounted at an annual rate of 3%.
Cost data:
The two main cost categories were administration of the two chemotherapy regimens, and rescue therapy. The latter category included the costs of high-dosage chemotherapy followed by blood aphaeresis, and a set of imaging, histological, haematological, and biochemical investigations. Hospitalisations were also included in the economic analysis. The resource use for chemotherapy regimens was derived from the MinT study, while data on quantities of resources used for rescue therapy were based on a published Italian study. Unit costs were derived from official Italian price lists, such as the those of the Agenzia Italiana del Farnaco, for drugs, or Italian DRGs for hospitalisations. The costs were in Euros (EUR). The price year was 2007 and a 3% annual discount rate was applied to costs incurred after the first year of treatment.
Analysis of uncertainty:
A univariate sensitivity analysis was carried out around three variables: complete response at five months; relapse-free survival at three years; and overall survival at three years. The three analyses used the lower (least favourable) limit of the 95% confidence interval (CI) for R-CHOP and the upper (most favourable) limit for CHOP. The discount rate was also varied. Finally, a threshold analysis was carried out by varying the cost of the rescue therapy.