Improvement of the comprehension of written information given to healthy volunteers in biomedical research: a single-blind randomized controlled study.

Writing an informed consent form (ICF) for biomedical research is a difficult task. We conducted a multicenter single-blind randomized controlled trial to identify whether a working group or the systematic improvement in lexico-syntactic readability or an association of the two could increase the comprehension of the written information given to healthy volunteers enrolled in biomedical research. Participants were randomized to read one of four versions of the ICF: unchanged ICF (A), ICF with systematic lexico-syntactic readability improvement (B), ICF modified by a working group (C), and ICF modified by the working group followed by systematic lexico-syntactic improvement (D).