Informed consent process in clinical trials: development of a patient-reported questionnaire

Objective: To develop a Spanish-language questionnaire aimed at evaluating patients' perception of the way they are briefed and their consent is obtained prior to participating in clinical trials. The tool was conceived to evaluate the following aspects: patients' personal experience, the way the informed consent process was implemented in practice, patients' level of satisfaction with the process, and their level of understanding of the study itself. Method: This study looked into the development, adaptation and validation of a self-administered questionnaire intended to evaluate the informed consent process on the basis of information provided by respondents. The steps followed included: literature review, generation of an items pool, drawing up of the questionnaire, expert review, piloting, and reading ease optimization and analysis. A commonly-used English-language questionnaire was evaluated, translated into Spanish and adapted so as to determine the extent to which subjects understood the information conveyed to them. Results: In its final version, the questionnaire came to comprise four sections intended to evaluate: 1) socio-demographic data; 2) practical aspects related with the development of the informed consent process; 3) patients' perception of the process (satisfaction, expectations and motivations); and 4) their level of understanding. Understanding was gaged using the QuIC questionnaire, translated by three bilingual translators. Additional questions were included to evaluate the understanding of concepts related with blinding and therapeutic misconception. The validity of the contents was evaluated by consulting with an expert panel. The reading ease analysis yielded an IFSZ score of 64.34, equivalent to an "average difficulty" grade on the Inflesz scale. In the pilot study, interviews were held with 32 patients, who did not appear to have any difficulties in understanding the questions asked of them or in using Likert-type scales to respond. Mean completion time was 16.6 minutes. Conclusions: The tool developed as part of this study has shown itself capable of providing an understanding and an assessment of the informed consent process from the perspective of a patient who is invited to participate in a clinical trial. Implementation of the questionnaire could help investigators ascertain that the process has been correctly executed and identify specific aspects that may require to be changed or optimized.