The expected lifetime cost was EUR 49,562 for CHOP, EUR 59,521 for rituximab induction and CHOP, and EUR 68,331 for rituximab induction and maintenance and CHOP; the addition of rituximab as induction resulted in an additional cost of EUR 8,810, and as induction and maintenance it added EUR 18,769.
The average QALYs were 3.90 with CHOP, 4.72 with rituximab induction, and 5.21 with rituximab induction and maintenance; the addition of rituximab maintenance resulted in a gain of 0.49 QALYs compared with rituximab induction, and 1.31 QALYs compared with CHOP.
Compared with CHOP alone, the incremental cost-effectiveness ratio for rituximab induction and maintenance was EUR 14,360 per QALY gained and for rituximab induction it was EUR 12,123 per QALY gained. Compared with rituximab induction, the incremental cost-effectiveness ratio of induction and maintenance was EUR 18,147 per QALY gained.
The one-way sensitivity analysis found that the results were relatively insensitive to the changes in the key parameters. The CEAF showed that rituximab induction and maintenance was cost-effective in 61.6% of simulations at a EUR 20,000 threshold, 95.3% at a EUR 30,000 threshold, 99.7% at a EUR 40,000 threshold, and 100% at a EUR 50,000 threshold. The EVPI was estimated to be EUR 1,240 at a willingness to pay of EUR 12,123, and EUR 5,196 at a willingness to pay of EUR 18,147 per QALY gained.