An enhanced participant information leaflet and multimedia intervention to improve the quality of informed consent to a randomised clinical trial enrolling people living with HIV and obesity: a protocol for a Study Within A Trial (SWAT)

BACKGROUND: It is the investigator’s responsibility to communicate the relevant information about a clinical trial to participants before they provide informed consent to take part. Systematic reviews indicate that participants often have a poor understanding of the concepts which are key to ensuring valid informed consent, such as randomisation and risks/discomforts. Paper-based participant information leaflets and informed consent forms (PIL/ICFs) are becoming longer and are often too complex for many participants. Multimedia interventions and enhanced PIL/ICFs have been trialled in an attempt to improve participants’ understanding of various aspects of research studies. However, there is insufficient empirical evidence to determine how effective such interventions are. This protocol describes a study to evaluate whether an enhanced PIL/ICF and website help research participants to understand important information about a human immunodeficiency virus (HIV) randomised clinical trial. METHODS: This Study Within A Trial (SWAT) is a prospective, multi-centre, randomised, controlled, parallel-group study embedded in a host clinical trial. The host trial (the SWIFT trial; EudraCT: 2019-002314-39) is a prospective, multi-centre, randomised, open-label, controlled trial investigating if semaglutide along with dietary advice assists individuals with HIV and obesity to lose weight, compared to dietary advice alone. For the SWAT, participants will be randomised in a 1:1 ratio to either the control (standard PIL/ICF) or the intervention (an enhanced PIL/ICF and a website which includes animations). The enhanced PIL/ICF and website were developed in line with the guidance from organisations which promote plain English and accessible public-facing materials in conjunction with HIV Ireland, a HIV advocacy organisation, and our previous work on consent documents. The primary outcome of the SWAT is the quality of informed consent, assessed by a validated comprehension test—the modified Deaconess Informed Consent Comprehension Test (DICCT). The DICCT will be administered within 48 h of consent to the host trial. The secondary is recall, measured by the modified DICCT questionnaire scores 2 weeks post-consent to the host trial. DISCUSSION: The results of this SWAT will add to the methodological evidence base on the use of multimedia to improve the quality of informed consent to randomised clinical trials. TRIAL REGISTRATION: ClinicalTrials.govNCT04174755. EudraCT 2019-002314-39. SWAT 160, Northern Ireland Hub for Trials Methodology Research SWAT repository (Clarke M, et al., Trials. 16:P209, 2015). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05979-y.