Evaluation of the readability of information sheets for healthy volunteersin phase-I trials

Objective: The aim of the present study was to assess whether information s heets/consent forms submitted to the healthy volunteers of the Clinical Pha rmacology Unit (C.P.U.) panel at Glaxo-Wellcome (Verona, Italy) could be co nsidered understandable and to verify the readability and comprehensibility of these documents. Since a volunteer bases his/her decision to take part in a study on the information sheet provided, it is of paramount ethical im portance to know whether the sheet conveys all relevant information. In add ition, a thorough awareness by the volunteer of the reasons and procedures of the study would increase compliance. Methods: Four indices were used: Flesh-Vacca, Kincaid, Gunning's Fog and Gu lpease. All indices rate the degree of difficulty of a text, in the light o f the level of schooling of the target population. The documents evaluated were information sheets presented to volunteers. The level of schooling of the population that participated in at least one study was determined: 61.7 % of volunteers finished high school and 22.6% had a University degree or d iploma; the remaining 15.7% did not finish high school or the datum was not available. Results: The results showed that, when the present study began, all informa tion sheets were "readable" by all volunteers who had at least finished hig h school. After these preliminary results, some additional linguistic and g raphic refinements were adopted in drawing up information sheets. Readabili ty improved to such a degree that all information sheets could be understoo d by virtually all volunteers. Conclusion: A number of suggestions were identified, which are set out in t his paper to assist in the preparation of improved information sheets and a recommendation to value the readability of consent sheets before giving th em to the volunteers. The suggestions were split into three categories: com munications to the volunteer, text format and text organisation.