The principle objective of this randomised controlled trial is to assess whether an improvement in lexico-syntactic readability combined with adherence to French recommendations for good practice in writing the Information and Consent Form (ICF) given to patients participating in clinical trials, increases their understanding of the information compared to conventional written information, in real (not simulated) conditions.

The quality of written information given to people participating in clinical trials is essential as by law all volunteers have to be informed of a certain number of key elements. Those elements that are necessary to understanding and making a decision as to whether to participate in the trial are presented to the volunteer in the information and consent document (ICD).

Many terms used in the ICD are of necessity medical terms and sometimes difficult to understand for the person who may participate in the study.

Several factors are involved when a reader receives a text, and one of the difficulties of intelligibility can be the lexico-syntactic readability.

The lexico-syntactic readability is the only element of intelligibility that can be readily quantified, using the Flesch-Kincaid index. It is also an element that can be very easily modified without changing the sense of the information.

In the QuIP-3 study, which we performed in 2003, it appeared that the lexico-syntactic readability of ICF is very low, lower than that of texts used in university level classics examinations. Furthermore, there is no correlation between the density of information and readability (QuIP-5 study).

It seems to be necessary to assess the understanding of those participating in clinical trials in terms of logical and cognitive intelligibility (representativeness and interpretability of the information and consent forms). Indeed, a text may be unreadable according to the Flesch score, in lexico-syntactic terms, but perfectly understood and interpreted.

As no questionnaire had been validated in French, we validated the " Questionnaire d'Evaluation de la Compréhension de l'Information Ecrite par les Malades or QECIEM " (Questionnaire measuring patient comprehension of written information) (QuIP-4). This questionnaire can be used to measure both objective and subjective general understanding by a patient to be included in a therapeutic study, irrespective of the pathology.

Inclusion Criteria:

• Subject considered suitable to participate in one of the clinical trials selected for the LISYCOM study
• Age > 18 years

Exclusion Criteria:

• Illiteracy or inability to read French
• Neurological deficiency making reading impossible (attention disorders, aphasy, etc)
• Refusal to participate