Cost-minimization analysis of tadalafil in the treatment of pulmonary arterial hypertension under the perspective of the Brazilian Public Health Care System

Abstract

Objectives: To comparatively assess costs of tadalafil and sildenafil when used for treating adults with pulmonary arterial hypertension (PAH) under the perspective of the Brazilian Public Health Care System (BPHS). Methods: A cost-minimization model was built using the TAD data from the Galié et al. study to estimate curves of time to “Clinical Worsening”, assuming efficacy equivalence between TAD and SIL, thus comparing only incremental costs. Two therapeutic strategies were compared: TAD 40 mg/day and SIL with flexible doses (starting in 60 mg/day). Costs were assessed for the 1 year time horizon. Unit costs were abstracted from BPSH reimbursement lists. Results: In the cost minimization analysis (assuming similar efficacy), the model estimated an incremental cost of BRL 23.99 per cycle of treatment when SIL is replaced by TAD, resulting in an yearly incremental cost of BRL 311.92 assuming TAD and SIL fixed doses of 40mg and 60 mg/day, respectively. When the average dose was ranged from 60 mg to 240 mg, the incremental cost varied from BRL 311.92 to - BRL 64,328.20 in the one-way sensitivity analysis. Conclusion: Assuming similar efficacy for TAD and SIL, the incremental cost of TAD versus 60 mg fixed doses of SIL was positive (higher costs), however doses of SIL up to 240 mg resulted in significant savings for the BPHS.