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We read with interest the recent paper from Barnett and colleagues,1 reporting the impact of different styles of informed consent forms proposed to children; it is one of the few papers on this important topic. Indeed, the content of informed consent documents (ICD) is a crucial element in the process of providing information to participants in biomedical research. Clear comprehension of this information—that is, the ability to understand its meaning and its consequences, is of great importance. However, investigators sometimes have the feeling that volunteers do not fully understand the major concepts of the study in which they are enrolled, and this issue is specifically relevant to children. This feeling has been confirmed by several studies in adults. A study conducted in two public hospitals2 showed that 40.7% and 74.5% of patients respectively did not understand the content of the ICD for clinical studies in which they were enrolled. In a third study, 156 veterans were interviewed to determine their degree of understanding of a clinical protocol for which they had signed a consent form.3 Less than 10 weeks after signing, only 10% could totally describe the objective of the study. More recently, Joffe et al validated a questionnaire to determine the quality of informed consent in phases 1, 2, and 3 of cancer clinical trials.4 The main result was that many patients did not recognise non-standard treatment (74%), the potential for incremental risk (63%), or the uncertainty of benefit to themselves (29%).
We carried out an initial study, QuIP-15 in which we compared the lexico-syntactic readability of informed consent documents, from the Rhône-Alpes region (France) with reference texts corresponding to five school levels, using the Flesch and Cordial readability scores. We showed that lexico-syntactic readability of French informed consent documents was worse than the readability score of the most difficult reference texts (university level). In a subsequent study, QuIP-3, we further showed that review by French Ethic committees did not improve the lexico-syntactic readability of an ICD,6 while increasing its length.
In the present study, Barnet et al suggest that a story format was clearly superior in maximising children’s understanding. Such data are important in our practice of biomedical research, as they should trigger investigators to promote such types of leaflets. However, several questions remain unanswered. Firstly, the questionnaire used probably only reflects part of the whole comprehension. The development of a questionnaire is usually a long term process that involves item generation, review, and selection. Its validation needs a survey carried out on a small group of subjects, and implies an analysis of the content and construct validity. Although a lighter process may be used for the present study, it would be interesting to know how these items were selected and whether a survey was performed prior to the general study. Secondly, this directive questionnaire prompts answers, whereas free recall would provide data on the amount and the type of information spontaneously understood, which could differ from that prompted.7 However, free recall itself is debated as most studies use the percentage of discrete bits of information memorised, which is a poor indicator of comprehension. A more accurate analysis needs the use of specific language analyser software that requires specific knowledge to be used. Thirdly, another potential pitfall is the place where the study took place. It is tempting to conclude that children’s answers would be the same at hospital or at the doctor’s office, but this is probably wrong, as in different locations, their attention would differ. It would add much to our knowledge to determine whether such a story format increases children’s comprehension in a real situation.
In conclusion, the work of Barnet et al further suggests that we may, and should, improve adults’ and children’s comprehension in biomedical research. As patients become more and more associated in the process of clinical research, this is an important area of improvement for the future.
Competing interests: none declared
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