Readability of patient information can be improved.

Introduction: The number of participants in medical experiments has declined and consent often rests on perilous ground because the participant information sheet (PIS) on which informed consent rests preserves identification with the expert environment. This study explores to which extent research ethics committee (REC) members appreciate this problem.

Methods: A retrospective analysis of ten REC applications were subjected to a naïve reading followed by structural analysis to generate themes and subthemes to guide structured REC member focusgroup interviews. This analysis informed a prospective survey where REC members registered terms and phrases posing comprehension barriers to lay receivers.

Results: Main barriers of comprehension were aspects of contents presentation and specialised terminology. Problematic terms centred mainly on epidemiology, design, descriptive and topographic anatomy and physiology, diagnostic procedures and medicines. Contents problems centred on irrelevant and superfluous information and poor presentation.

Conclusion: The language, structure and format of the PIS should be improved. Avoiding technical jargon or explaining it when it is used, using more common words when they are available and a clearer structure were identified as potential targets of intervention.

Funding: not relevant.

Trial Registration: not relevant.