Background Enrolment is one of the most challenging aspects of conducting clinical trials, preceded by the process of informed consent (IC). Different strategies to improve recruitment in clinical trials have been used, including electronic IC. During COVID-19 pandemic, barriers to enrolment have been evident. Although digital technologies were acknowledged as the future of clinical research and potential advantages were shown for recruitment, electronic informed consent (e-IC) has not yet been globally adopted. The purpose of this review is to investigate the effect of using e-IC on enrolment, practical and economic benefits, challenges, and drawbacks when compared to traditional informed consent, through a systematic review. Methods Embase, Global Health Library, Medline, and The Cochrane Library databases were searched. No limit was set for publication date, age, sex, or study design. We included all studies within a randomized controlled trial (RCT), published in English, Chinese or Spanish, evaluating the electronic consent process used in the parent RCT. Studies were included if any of the three components ((i) information provision, (ii) participant’s comprehension, (iii) signature) of the IC process was designed as electronic, whether administered remotely or face-to-face. The primary outcome was the rate of enrolment to the parent trial. Secondary outcomes were summarized according to the various findings reported on the use of electronic consent. Results From a total of 9069 titles, 12 studies were included in the final analysis with a total of 8864 participants. Five studies of high heterogeneity and risk of bias showed mixed results on the efficacy of e-IC on enrolment. Data of included studies suggested e-IC could improve comprehension and recall of study-related information. Meta-analysis could not be conducted due to different study designs and outcome measures and the predominantly qualitative findings. Conclusion Few published studies have investigated the impact of e-IC on enrolment and findings were mixed. e-IC may improve participant’s comprehension and recall of information. High-quality studies are needed to evaluate the potential benefit of e-IC to increase clinical trial enrolment. Trial registration PROSPERO CRD42021231035. Registration date: 19-Feb-2021.

Background Enrolment is one of the most challenging aspects of conducting clinical trials, preceded by the process of informed consent (IC). Different strategies to improve recruitment in clinical trials have been used, including electronic IC. During COVID-19 pandemic, barriers to enrolment have been evident. Although digital technologies were acknowledged as the future of clinical research and potential advantages were shown for recruitment, electronic informed consent (e-IC) has not yet been globally adopted. The purpose of this review is to investigate the effect of using e-IC on enrolment, practical and economic benefits, challenges, and drawbacks when compared to traditional informed consent, through a systematic review. Methods Embase, Global Health Library, Medline, and The Cochrane Library databases were searched. No limit was set for publication date, age, sex, or study design. We included all studies within a randomised controlled trial (RCT), published in English, Chinese or Spanish, evaluating the electronic consent process used in the parent RCT. Studies were included if any of the three components (i. information provision, ii. participant’s comprehension, iii. signature) of the IC process was designed as electronic, whether administered remotely or face-to-face. The primary outcome was the rate of enrolment to the parent trial. Secondary outcomes were summarised according to the various findings reported on the use of electronic consent. Results From a total of 9069 titles, 12 studies were included in the final analysis with a total of 8864 participants. Five studies of high heterogeneity and risk of bias showed mixed results on the efficacy of e-IC on enrolment. Data of included studies suggested e-IC could improve comprehension and recall of study-related information. Meta-analysis could not be conducted due to different study designs and outcome measures and the predominantly qualitative findings. Conclusion Few published studies have investigated the impact of e-IC on enrolment and findings were mixed. e-IC may improve participant´s comprehension and recall of information. High quality studies are needed to evaluate the potential benefit of e-IC to increase clinical trial enrolment. Trial registration: International Prospective Register of Systematic Reviews (PROSPERO CRD42021231035)