The assessment of readability of information sheets/consent forms in clinical studies with healthy volunteers.

Abstract

The “readability” of a text depends on many variables, both subjective and objective. Subjective variables reside in the person who is going to read the text and include attention, motivation, mood, etc. Objective variables reside in the text itself: grammar, usage of tenses, etc.

The aim of the present study was to assess whether information sheets/consent forms submitted to the volunteers of the Clinical Pharmacology Unit Panel at Glaxo-Wellcome (Verona, Italy) could be judged comprehensible, after having analysed the objective variables.

Since a volunteer bases his/her decision of participating in a study on the information sheet provided, it is of paramount ethical importance to know whether the sheet conveys all relevant data. In addition, by making the volunteer fully aware of the reasons and procedures of the study, this would also increase his/her compliance.

Four indices, recognized by the international literature, were used: Flesh- Vacca, Kincaid, Gunning’s Fog and Gulpease; the software Errata Corrige by Expert System Company was adopted for calculations. All indices give a value which rates the degree of difficulty of a text, considering the level of schooling of the target population.

The documents evaluated were information sheets presented to volunteers in the period January ’96-September ’97. The level of schooling of the population which participated in at least one study in the above period was determined: 61.7% of volunteers finished high school and 22.6% earned a University degree, this making a total of 84.3% of the Panel.

The results showed that until March ’97, when the present study began, all information sheets were “readable” by all volunteers who finished at least high school. After these preliminary results some precautions were implemented. Readability improved to such a degree that any information sheet could be understood by virtually all volunteers.

A number of tips and suggestions were identified, which are given here as a useful tool when preparing an information sheet.