An audit of questions asked by participants during the informed consent process for a phase 2/3 COVID-19 vaccine regulatory study at a tertiary referral centre.

Objective: To evaluate questions asked during the informed consent process by adult participants in a COVID-19 vaccine regulatory study conducted at our center in 2020.

Methods: After approval by the IEC, informed consent documents and consent narratives were evaluated. We collated the total number and nature of questions. We then looked at the association between education, gender, socio-economic status, employment status, the language of consent, and number of questions. Between-group comparison (female vs male, unemployed vs employed, primary school vs secondary school vs graduate vs post-graduates, upper vs upper-middle vs middle vs lower middle vs lower) for the number of questions asked was done using univariate analysis followed by multivariate regression analysis with post hoc Tukey's test. Independent variables were gender, employment status, education and socioeconomic status and the dependent variable was the number of questions asked by the participant. All analyses were done at 5% significance. Content analysis was done in addition by creating categories after evaluation and coding them.

Results: A total of N = 129 consents from the same number of participants were evaluated. A total of N = 127/129 participants asked at least one question. Sixty-seven percent of participants asked questions related to the study procedure, followed by 44.9% of participants who asked questions related to the safety of vaccine or placebo. A total of N = 295 questions were asked by the 127 participants. In content analysis, 149/295 (50.5%) questions were on study-related procedures followed by one quarter 76/295 (25.8%) based on safety associated with Investigational Product. Very few participants [2.4%] asked about post-trial access as the regulatory trial was a placebo-controlled trial. None of the independent variables were found to be associated with the number of questions.

Conclusion: The majority of the questions asked by the participants were about study-related procedures and vaccine safety. No association was found between any of the independent variables and the number of questions asked. However, there were differences in the demographics of the trial participants between the pandemic and pre-pandemic era.