Treatment of pulmonary arterial hypertension: a preliminary decision analysis.
STUDY OBJECTIVE: New therapies for pulmonary arterial hypertension (PAH) improve functional status, quality of life (QOL), and survival. Clinicians must chose between very different therapies without the availability of comparison studies. We constructed a "virtual" clinical trial to help inform these treatment choices. DESIGN: We compare key outcomes related to survival, costs, and QOL using a Markov-type decision model to estimate the expected outcomes and costs for PAH patients treated for 1 year with bosentan and treprostinil compared to patients treated with epoprostenol, as well as patients treated with bosentan compared to those treated with treprostinil. The allowed transitions in the model were between World Health Organization functional class I to IV and death. Transition probabilities were based on observed transitions for bosentan. Treatment effect was estimated using 6-min walk data for treprostinil and epoprostenol. Utilities were calculated from estimated EuroQol health states. Cost was estimated from average wholesale price and Medicare reimbursement data. The effects of changing values of input variables on the key outcomes were calculated. RESULTS: Treatment with bosentan compared to treatment with either epoprostenol or treprostinil was less costly and resulted in a greater gain in quality-adjusted life years (QALYs). Conversely, treprostinil was significantly more expensive than epoprostenol, without an appreciable gain in QALYs. These findings were not substantially affected by the reasonable adjustments of transition probabilities, utility values, or tachyphylaxis to epoprostenol. CONCLUSION: Treatment with bosentan is more cost-effective than treatment with either treprostinil or epoprostenol. In addition, a net improvement in quality-adjusted survival may be expected.