Importance: Few studies are available on informed consent (IC) among detained persons, even with ethics being a critical aspect of prison research. In IC research, audiovisual material seems to improve understanding and satisfaction compared with conventional paper-based material, but findings remain unclear.
Objective: To compare audiovisual and paper-based materials for 1-time general IC for research in prisons.
Design, setting, and participants: This cross-sectional randomized clinical trial was conducted in 2 corrections facilities in Switzerland (an adult prison and a juvenile detention center). The study was conducted from December 14, 2019, to December 2, 2020, in the adult prison and from January 15, 2020, to September 9, 2021, in the juvenile detention center. In the adult prison, study participation was offered to detained persons visiting the medical unit (response rate, 84.7%). In the juvenile detention center, all newly incarcerated adolescents were invited to participate (response rate, 98.0%).
Interventions: Participants were randomized to receive paper-based conventional material or to watch a 4-minute video. Materials included the same legal information, as required by the Swiss Federal Act on Research Involving Human Beings.
Main outcomes and measures: The main outcome was acceptance to sign the IC form. Secondary outcomes included understanding, evaluation, and time to read or watch the IC material.
Results: The study included 190 adults (mean [SD] age, 35.0 [11.8] years; 190 [100%] male) and 100 adolescents (mean [SD] age, 16.0 [1.1] years; 83 [83.0%] male). In the adult prison, no significant differences were found between groups in acceptance to sign the IC form (77 [81.1%] for paper-based material and 81 [85.3%] for audiovisual material; P = .39) and to evaluate it (mean [SD] correct responses, 5.09 [1.13] for paper-based material and 5.01 [1.07] for audiovisual material; P = .81). Understanding was significantly higher in the audiovisual material group (mean [SD] correct responses, 5.09 [1.84]) compared with the paper-based material group (mean [SD] correct responses, 4.61 [1.70]; P = .04). In the juvenile detention center, individuals in the audiovisual material group were more likely to sign the IC form (44 [89.8%]) than the paper-based material group (35 [68.6%], P = .006). No significant difference was found between groups for understanding and evaluation. Adults took a mean (SD) of 5 (2) minutes to read the paper material, and adolescents took 7 (3) minutes.
Conclusions and relevance: Given the small benefit of audiovisual material, these findings suggest that giving detained adults and prison health care staff a choice regarding IC material is best. For adolescents, audiovisual material should be provided. Future studies should focus on increasing understanding of the IC process.
Trial registration: ClinicalTrials.gov Identifier: NCT05505058.