Informed Consent in Online Studies. How Much Do Participants Really Understand, and Can That Be Changed?

Abstract

Background: Participants must provide informed consent (IC) to participate in a study. To this end, they must first read through and understand the information letter and the informed consent sheet. Objectives: This online study examined whether the documents used to obtain IC are being properly read and understood, and whether the design of the format influences participants' understanding of the IC. Methods: 214 participants were randomly assigned to one of three conditions (two different information letters and consent forms and a control condition). We assessed their reading of these documents based on self-report and reading time; comprehension of the IC was assessed using multiple-choice questions. Results: Most participants did not read the IC documents completely and did not sufficiently understand the relevant contents. Regarding the IC documents, both versions lead to a higher reading rate than the control document. Conclusion: The results provide information for optimizing the design of IC forms.