Currently, European legislation requires that patient information leaflets accompanying all prescription medicines list the adverse effects of the medicine and provide guidance on its safe and appropriate use. In 2025, the European Medicines Agency (EMA) launched a public consultation on a proposal to include a new 'key information section' in the patient leaflets across Europe. A key information section is intended to help users quickly access non-promotional information about both the drug benefits and risks of a drug.
This study aims to evaluate the effect of including information about drug benefits, either qualitatively or both qualitatively and quantitatively, on individuals' expectations of a new cancer drug, using the European patient leaflet.
In this online randomized controlled trial, a nationally representative sample of adults from the United Kingdom will be randomly assigned to 1 of 3 versions of a patient leaflet: (1) the standard patient information leaflet (control), (2) a leaflet with the EMA's proposed key information section containing qualitative statements, or (3) a leaflet with a key information section providing both qualitative and quantitative data on the drug's benefits and harms. The patient leaflet used in the study was for a cancer drug (tivozanib).
The primary outcome is participants' expectations regarding the drug's benefits and harms. Secondary outcomes include participants' understanding of the information, participants perceived magnitude of the drug's benefits and harms, and their satisfaction with the leaflet content.