Patients' Benefit-Risk Preferences for Chronic Idiopathic Thrombocytopenic Purpura Therapies

BACKGROUND: Idiopathic thrombocytopenic purpura (ITP) primarily is a disorder of adults characterized by autoantibody-induced platelet destruction and reduced platelet production, leading to a low peripheral blood platelet count. The long-term management of many patients with chronic ITP is unsatisfactory, largely due to the variable efficacy and risks of severe adverse effects associated with current treatment options. OBJECTIVE: To estimate patients' benefit-risk preferences for treatments for ITP. METHODS: Patients' adverse event risk tolerance and the levels of benefit required to offset possible risks were evaluated using choice-format conjoint analysis. Subjects chose between pairs of hypothetical treatment alternatives defined by probability of achieving safe platelet levels, need for corticosteroids, mode of administration, risk of rebound, risk of elevated liver enzyme levels, and risk of thromboembolism. RESULTS: In this study, we demonstrate that patients have clear and measurable benefit-risk preferences that physicians should consider when discussing treatment options with their patients. Patients were willing to accept significant risks of adverse events in return for an increase in the probability of achieving safe platelet levels, to avoid corticosteroids, and for more convenient administration. Patients were willing to accept significant risks of rebound and elevated liver enzymes for improvements in outcomes. CONCLUSIONS: These results demonstrate that patients with ITP are willing to accept treatment-related risks in exchange for improvements in treatment efficacy and administration attributes and suggest the importance of considering a patient's benefit-risk preferences during discussions of therapeutic options.