gms | German Medical Science

Background: By 2003, the readability of informed-consent forms that were provided by institutional review boards of US medical schools did not meet standards, according to the Flesch–Kincaid formula. We hypothesized that the readability of templates for informed-consent is still not sufficient to be understood by the majority of potential research subjects more than ten years later.

Methods: Using the Flesch–Kincaid formula we analysed the current templates for informed-consent forms of the United Kingdom National Health Service (UK NHS), as well as those of ethics committees and umbrella organizations in Austria, Germany, and Switzerland. The Flesch Index and the education level required to understand the text according to the formula was assessed for the consent part of all templates.

Results: The templates of 3 umbrella organizations and 5 individual ethics committees, used at a total of 72 ethics committees in the German-speaking countries, have been analysed. As a benchmark, we have analysed the UK NHS template. The NHS and Swissethics consent forms had the best readability with indices of 49 and 26 respectively. These scores correspond to a secondary educational level. All other templates require a tertiary (postsecondary) education level of reading comprehension.

Conclusion: All analysed informed-consent forms require a secondary or even tertiary education level. Throughout the European Union, 24.2% of the population hold a tertiary degree, and 45.5% a secondary degree indicating that a considerable number of informed-consent forms may be legally invalid. It is remarkable that across several countries, consent forms continue to increase in length, complexity, and the incorporation of legal language, despite a number of reports on this issue and suggestions for improvement.