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Research ethics
Performance-based readability testing of participant materials for a phase I trial: TGN1412
  1. P Knapp1,
  2. D K Raynor1,
  3. J Silcock1,
  4. B Parkinson2
  1. 1
    School of Healthcare, University of Leeds, UK
  2. 2
    Making Sense Design, Sheffield, UK
  1. Correspondence to Dr Peter Knapp, School of Healthcare, University of Leeds, LS2 9LN, UK; p.r.knapp{at}


Background: Concern has been expressed about the process of consent to clinical trials, particularly in phase I “first-in-man” trials. Trial participant information sheets are often lengthy and technical. Content-based readability testing of sheets, which is often required to obtain research ethics approval for trials in the USA, is limited and cannot indicate how information will perform.

Methods: An independent-groups design was used to study the user-testing performance of the participant information sheet from the phase I TGN1412 trial. Members of the public were asked to read it, then find and demonstrate understanding of 21 key aspects of the trial. The participant information sheet was then rewritten, redesigned and tested on 20 members of the public, using the same 21-item questionnaire.

Results: On the original TGN1412 participant information sheet, participants could not find answers and some of the found information was not understood. Six of 21 questions, including those relating to placebo, follow-up visits and the emergency phone number, were found by eight or fewer of 10 participants. The revised information sheet performed better, with the answers to 17 of 21 questions found and understood by all 20 participants.

Conclusions: Tests showed that the TGN1412 participant information sheet may not inform participants adequately for consent. Revising its content and design led to significant improvements. Writers of materials for trial participants should take account of good practice in information design. Performance-based user testing may be a useful method to indicate strengths and weaknesses in trial materials.

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  • ▸ Figs 1–6 are published online only at

  • Competing interests DKR is a director of LUTO Research Ltd, a University of Leeds spin-out company that provides information writing and testing services to the pharmaceutical industry. JS is chair of an NHS research ethics committee, but the views expressed are those of the authors, not necessarily those of the National Research Ethics Service. BP provides graphic design services to the pharmaceutical industry and the NHS.

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