OBJECTIVE: The aim of this study is to estimate the willingness of multiple sclerosis (MS) patients to accept life-threatening adverse event risks in exchange for improvements in their MS related health outcomes. METHODS: MS patients completed a survey questionnaire that included a series of choice-format conjoint tradeoff tasks. Patients chose hypothetical treatments from pairs of treatment alternatives with varying levels of clinical efficacy and associated risks. RESULTS: Among the 651 patients who completed the survey, delay in years to disability progression was the most important factor in treatment preferences. In return for decreases in relapse rates from 4 to 1 and increases in delay in progression from 3 to 5 years, patients were willing to accept a 0.38% annual risk of death or disability from PML, a 0.39% annual risk of death from liver failure or a 0.48% annual risk of death from leukemia. CONCLUSIONS: Medical interventions carry risks of adverse outcomes that must be evaluated against their clinical benefits. Most MS patients indicated they are willing to accept risks in exchange for clinical efficacy. Patient preferences for potential benefits and risks can assist in decision-making
