Lexicon of informed consent language in trials 

 

The core components of informed consent are: disclosure (providing complete information), understanding (ensuring the individual comprehends the information), voluntariness (confirming the decision is free of coercion), and competence (ensuring the individual has the capacity to make a decision). These principles are fundamental to ethical medical and research practices, ensuring individuals have the autonomy to make decisions about their own bodies and health. 

There is a rich and often confusing vocabulary of terms used to describe informed consent - the lexicon below describes commonly used informed consent terms. 

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• Advanced consent: The process by which a potential research participant provides consent in advance for possible future enrolment in a clinical trial, to take effect if they later meet the trial's eligibility criteria, such as during a medical emergency or a period of incapacity. This consent may be specific to a particular trial, may outline the individual’s preferences for participation in certain types of research, or may reflect general values and wishes to guide researchers about their willingness to participate in future research. (Niznick et al., 2023)

• Blanket consent: “A type of consent that is given only once, covering any future use of the material” or information provided by the participant (Dankar et al., 2019). It can be used without limitations on the type of research or need for re-contact. It differs from “broad consent” in that it typically lacks restrictions or oversight mechanisms.  

• Broad consent: Refers to a staged-informed consent procedure, specifically within the Trials within Cohorts (TwiCs) design, where participants give broad consent for potential future randomization to study arms at the start of their involvement in a cohort. This initial consent allows them to be assigned to intervention or control groups in future trials without further specific notification, though they are contacted again if selected for an intervention to provide additional consent for that specific trial (Young -Afat, 2016).  

• Broadcast consent (or Opt-out consent): This model involves broad notification to a group of potential participants (e.g., through flyers, brochures, or online announcements) about the research study. Participants are then given the option to "opt-out" or decline participation if they do not wish to be involved. This method can be helpful in large-scale trials where it may be impractical to obtain individual consent from every participant. (McKinney et al. 2015). 

• Clinical (medical) consent: The process of obtaining a patient’s permission before performing a medical procedure, treatment, or intervention. It ensures the patient understands their diagnosis, treatment options, risks, and alternatives. Clinical consent alone is not sufficient for research participation (Del Carmen & Joffe, 2005).   

• Cohort consent: In the TwiCs design, this refers to informed consent obtained from all participants at cohort entry for the regular collection (Amstutz et al., 2024). 

• Community/ group consent: Seeking informed consent from a community leader, usually in addition to individuals. This type of consent is relevant in global research and research involving indigenous people (Strauss et al., 2001).  

• Consent derogation: refers to a legal exception that allows an action to take place without the usual requirement of obtaining consent, under specific and limited circumstances defined by law or regulation (EDPB, 2018).

• Deferred consent: also known as research without prior consent, is a process where participants are enrolled in a research study without obtaining their consent beforehand, and consent is sought later. This is typically used in emergency research situations where it's not feasible to get consent before the research intervention due to the patient's condition (e.g., unconsciousness, severe illness). The idea is to get consent from the patient or their legal representative as soon as practically possible after the initial intervention. (Fitzpatrick et al., 2022). 

• Deemed consent: A situation where a person is considered to have given informed consent to participate in a clinical trial if, after being properly informed, they do not object. In other words, consent is assumed or presumed unless the individual explicitly opts out of participation. (HRA, 2014)

• Dynamic consent: a new approach to consent where participants have more autonomy over the use of their personal information by allowing for alterations in their consent choices in real time, developed as a response to evolving data protection frameworks resulting in greater trust in researchers and new legislation (Budin-Ljosne et al., 2017). 

• Electronic Consent: This involves obtaining consent through digital platforms, such as online forms or applications, and is becoming increasingly prevalent. 

• Express consent: Informed consent that is explicitly given, verbally or written (HCPC).

• Fully informed consent: A commonly used phrase to denote the 'everything to everyone up front' consent approach (although there is no formal definition of this phrase or any mention in ICH-GCP guidelines). 

• General approval consent: light touch, consisting of passive information about study participation (e.g. leaflets, posters), without routine explanation of the studies by clinicians, and no specific opportunity to opt-out of participation. Patients are given information through institutional policies, newsletters, posters, and information sheets about routinely conducted lower risk research in their care setting that the institution thinks will not adversely affect patient care to ultimately learn which care is most effective (Kass et al, 2016). Clinicians do not routinely explain the study to the patient during appointments, and there are no study-specific opportunity to opt-out of participation. 

• Granular consent: giving individuals the ability to choose what specific aspects of data processing they consent to, rather than a single, broad agreement (European Data Protection Board, 2020). Instead of a single "yes" or "no" for all data processing, users are given separate options for different purposes and types of processing.   

• Implied Consent: This type of consent is inferred from a person's actions or behaviour, suggesting their agreement to participate (HCPC, 2024). For example, showing up for a scheduled appointment could be considered implied consent for a routine examination. 

• Integrated consent: combines the consent process for the clinical intervention with the consent for research participation. The patient provides consent for their clinical care, and this consent also covers their participation in the research study, as the research is integrated into their routine care. This model aims to reduce the burden on participants and streamline the process, particularly in settings where research is closely intertwined with clinical practice. (Kim et al., 2014). 

• Just in time consent: Consent discussions take place in two stages: an initial consent to research from all participants, and a later specific consent to randomized treatment only from those assigned to the experimental intervention (Vickers et al, 2018). Also known as two-stage consent. 

• Layered consent: Participants choose how much information they want. Key information for decision-making is provided in a short patient information sheet (layer 1) with additional optional information that is accessed separately (layer 2) - being developed by Leeds CTRU. 

• Meta consent: When participants are asked to express their preferences regarding when and how they wish to provide consent for future research using the data collected previously or for the data that will be stored in the future (Ploug & Holm, 2015).   

• Opt-in consent: Individuals must actively agree to participate, often by actively selecting an option to indicate their consent – classical/ standard consent approach. (Resnik 2024) 

• Opt-out consent: Individuals are included in a study or process unless they actively choose to withdraw. (Resnik 2024) 

• Oral Consent: This involves obtaining a person's agreement to participate through spoken words. It's typically used for routine procedures or when written consent isn't feasible. 

• Patient-centred informed consent: The process of obtaining patient information and consent aims to replicate that in real world routine health care. All cohort patients consent to provide observational data at the outset; however, consent to “try” a particular intervention is sought only from those offered that intervention, thus replicating the patient-centred information and consent procedures that exist in routine health care, where clinicians provide patients with the information they need, at the time they need it. The rationale for this approach is twofold. Firstly, the primary motive for patients to enter clinical trials is not altruism, but their own direct benefit as patients. Clinical trial informed consent procedures should, therefore, put the needs of the patient at the centre; that is, patients should not be told about treatments that they might not then receive, nor should they be told that their treatment will be allocated by chance. Secondly, the greater the similarity between patients’ experiences in trials and their experiences in routine health care, then the greater the generalisability of the trial results to patients in routine health care.(Relton et al., 2010) 

• Post randomisation consent: In the TwiCs design, this refers to the informed consent sought only from participants randomly allocated to the intervention arm, after randomisation has taken place(Amstutz et al., 2024). 

• Proportionate consent: refers to adopting procedures and practice appropriate with the balance of risk and benefits so that potential participants are not burdened by unnecessarily complex information sheets, but rather provided with information in a succinct and user-friendly manner, often times verbally. Current HRA guidance recognises the importance of proportionate approach to research and states researchers and Research Ethics Committees (RECs) should always ensure research procedures should be justified and proportionate.  

• Proxy/surrogate consent: Type of consent given by a legally authorized representative when participants cannot consent (e.g., children, unconscious patients) (Berg et al., 2013).  Closely linked to assent, which is agreeing to participate in research when the participant lacks full understanding (e.g., children, patients with dementia)). It can be expressed verbally or inferred based on the cooperation of the individual. It is not a legal requirement to obtain assent, however it is legally required to obtain proxy consent in circumstances when it is not possible to obtain informed consent from the participant (Slaughter et al., 2007).  

• Randomisation consent: In the TwiCs design, this refers to the informed consent obtained at cohort entry, where participants agree in advance to the possibility of being randomly selected for future interventions within the cohort (Amstutz et al., 2024). 

• Research consent: Informed consent in research encompasses “the full disclosure of the nature of the research”, the involvement of the participant, adequate level of understanding on the part of the participant and the voluntary choice of participation made by the participant (Dankar et al., 2019).   

• Specific consent: When informed consent is only sought for one particular research study and participants’ consent does not extend beyond this (Largent, 2016).   

• Staged consent:  This involves breaking down the informed consent process into separate, sequential stages to provide information and gain agreement at different points, rather than all at once. Participants can first consent to participate in the study's procedures and then separately consent to the randomized intervention itself (Vickers et al, 2018). Staged consent aims to improve understanding and engagement by allowing information to be presented and absorbed in manageable parts, promoting a more ongoing and meaningful dialogue with the individual (See Just-in-time consent, Tiered consent and Staged & Tailored consent).

• Staged & Tailored consent: This approach tailors the informed consent process to the needs of each participant at each stage of the trial (further details here). 

• Targeted consent: researchers focus on obtaining consent for specific aspects of the research that pose potential risks or require specific procedures (Wendler, 2015). for example, if a trial involves only minimal risk interventions, consent might be targeted to those specific procedures, rather than requiring a blanket consent for the entire trial. This approach can be particularly useful when some aspects of the trial are more routine than others.  

• Tiered consent: This represents an intermediate model between specific and broad consent approaches. Tiered consent allows participants to determine the extent of their consent. During the consent process, individuals are presented with a series of questions designed to establish the desired scope of their participation—ranging from study-specific consent to broader or general consent for future research. Also known as Multi-Layered Consent (Wiertz & Boldt, 2022). 

• Two-stage consent: An informed consent method that splits the traditional consent process into two phases, separating information about research procedures from details on the experimental intervention itself.  Originally known as Just in Time consent. 

• Waiver of consent: In certain situations, a waiver of consent may be granted by an Institutional Review Board (IRB) or ethics committee. This means that participants are not required to provide explicit consent before participating in the research (Baker et al., 2018). Waivers are typically granted when the research involves minimal risk, the waiver is necessary to conduct the research, and there is no way to obtain consent without compromising the study's objectives. Examples might include research using existing medical records or data where obtaining consent would be extremely burdensome or impractical. 

• Withdrawable consent: Individuals have the right to revoke their consent at any time (UKRI). 

• Written Consent: This is the most common form of consent, where the individual signs a document outlining the details of the procedure or study, including potential risks and benefits.