Eliciting Preferences for Prioritizing Treatment of Rare Diseases: the Role of Opportunity Costs and Framing Effects

Understanding societal preferences regarding resource allocation in the health sector has gained importance as countries increasingly base reimbursement decisions on economic evaluations. Preference elicitation using surveys, a common practice in the health sector, is subject to a range of framing effects. This research investigates the importance of (theoretically relevant) opportunity costs and (theoretically irrelevant) framing effects on stated preferences for prioritizing treatment of rare (orphan) diseases. We elicited preferences from Norwegians, aged 40-67, using simple trade-off exercises. Respondents were randomised to different opportunity costs of the rare disease or to different framings of the trade-off exercises. Respondents were quite sensitive to the visual presentation of the choice problem, and, to a lesser extent, to focusing and labelling effects. Elicited preferences varied little in response to large changes in opportunity costs, suggesting scope-insensitivity among respondents. Preferences for prioritizing treatment of rare diseases elicited using trade-off exercises are insensitive to (theoretically relevant) opportunity costs, but sensitive to (theoretically irrelevant) framing effects.