Digital Informed Consent/Assent in Clinical Trials Among Pregnant Women, Minors, and Adults: Multicountry Cross-Sectional Evaluation of Comprehension and Satisfaction

TL;DR

This study shows that digital informed consent materials, designed with input from participants, are effective in improving understanding and satisfaction across different groups in multiple countries.

Contribution

The study introduces eIC materials co-created with target populations, demonstrating their effectiveness in multinational clinical trials.

Findings

Objective comprehension scores exceeded 80% across all groups, with high satisfaction rates.

Format preferences varied by age group, with videos preferred by minors and pregnant women, and text by adults.

Cocreated materials were effective across countries but required cultural adaptation for optimal results.

Abstract

Informed consent (IC) is a cornerstone of ethical clinical research, yet comprehension gaps persist. The i-CONSENT guidelines aim to improve IC materials by enhancing clarity, accessibility, and tailoring them to the needs of diverse populations. This study evaluates the effectiveness of electronic IC (eIC) materials developed under these guidelines for 3 target populations—minors, pregnant women, and adults—across Spain, the United Kingdom, and Romania.

The primary aim of this study is to assess participants’ comprehension of and satisfaction with eIC materials tailored to their specific needs. The secondary objectives are to identify demographic predictors of comprehension, evaluate the cross-cultural applicability of materials, and explore format preferences.

A cross-sectional study was conducted with 1757 participants (620 minors, 312 pregnant women, and 825 adults), who reviewed eIC materials through a digital platform offering layered web content, narrative videos, printable documents, and infographics. Materials were co-designed using participatory methods, including design thinking sessions with minors and pregnant women, and online surveys with adults. Comprehension was assessed using an adapted version of the Quality of the Informed Consent questionnaire. Objective comprehension (part A) was categorized as low (<70%), moderate (70%‐80%), adequate (80%‐90%), or high (≥90%). Subjective comprehension (part B) was measured using a 5-point Likert scale. Satisfaction was evaluated through Likert scales and usability questions, with scores ≥80% considered acceptable. Multivariable regression models were applied to identify predictors of comprehension.

Objective comprehension exceeded 80% across all groups: minors (mean 83.3, SD 13.5), pregnant women (mean 82.2, SD 11.0), and adults (mean 84.8, SD 10.8). Women/girls outperformed men/boys (β=+.16 to +.36). Generation X adults scored higher than millennials (β=+.26, P<.001), while prior trial participation was associated with lower comprehension scores (β=−.47 to −1.77). Among minors, compared with participants from Spain with no previous clinical trial experience, comprehension was significantly lower in Spain (P=.03), Romania (P<.001), and the United Kingdom (P<.001). Format preferences varied: 382 out of 620 (61.6%) minors and 152 out of 312 (48.7%) pregnant women preferred videos, whereas 452 out of 825 (54.8%) adults favored text (P<.001). Satisfaction rates surpassed 90% in all groups (minors, 604/620, 97.4%; pregnant women, 303/312, 97.1%; and adults, 804/825, 97.5%), with 777 out of 825 (94.2%) adults also indicating that the materials facilitated understanding. While translated materials maintained high efficacy across countries, comprehension scores in Romania were lower among participants with lower educational levels (β=−1.05, P=.001). Materials cocreated in Spain were effective across countries but yielded higher comprehension within the original target population.

eIC materials developed following the i-CONSENT guidelines achieved high levels of comprehension and satisfaction across diverse populations, demonstrating scalability for multinational trials. Cocreation and multimodal design effectively addressed participant preferences; however, cultural adaptation remained crucial for optimizing outcomes. The negative impact of prior trial participation highlights the need for tailored engagement strategies for returning participants. Future research should explore regional disparities, evaluate interventions for overconfident returning participants, and validate these tools across broader cultural contexts.