[An analysis of patient information sheets for obtaining informed consent in clinical trials]

The written information provided to the potential participants in a clinical trial must have certain qualitative and quantitative characteristics to reach the ethical requirements governing the theory of the informed consent.

In a sample of 101 clinical trial protocols approved in two Spanish university general hospitals, the following items were evaluated: a) the amount and quality of the written information given to the patient, in accordance with the established in the Spanish legislation; b) the formal readability of this written forms, by means of the Flesch method, and c) the level of complexity of the vocabulary, by means of the number of non-comprehensible words for two volunteers unaware of the health professions, with high studies.

The balance of benefits and risks, the identification and the way of contact with the main investigator, the description of the alternative treatments and the specification of the compensations in case of lesions were the items with highest noncompliance. The mean global readability by means of the index of Flesch was of -12.7 (text with a high level of complexity). The mean percentage of words non-comprehensible for the volunteers that analyzed the texts was 0.3%.

The written form of information provided to the patient in the clinical trials developed in Spain has serious deficiencies, either in their formal readability (complexity of the linguistic structure) or in the amount and quality of the information that provides. These deficiencies could have a wrong influence in the appropriate obtention of the informed consent from the patients.