Assent forms and information materials for young participants
A paediatric trial seeks two agreements: the consent of the parent or legal representative, which makes enrolment lawful, and the assent of the child. For the child, a writer produces an assent form and the information materials that accompany it, adapts both to the child's age, gives the child a way to record a decision, and tests the drafts with young people.
Consent and assent
Research involving children raises more complex considerations than research with adults. Although children depend on their parents or legal guardian to provide written informed consent for their participation in clinical trials, they should be involved in the decision-making process if they have the capacity to assent. Assent is therefore given by children with capacity, in addition to consent by the legal representatives, and indicates their understanding of the trial procedures and their willingness to participate.
Paediatric trials distinguish consent from assent. Consent is the legal requirement, obtained from parents or legal representatives, without which a participant of minor age cannot be enrolled. Young people still have to receive all the information, which can be given through informational materials, and they have the right to give their assent. Assent is the young person's own voluntary agreement to take part, and it is highly recommended alongside parental consent in paediatric trials; some European countries make it a legal requirement for minors of a certain age. The assent and the information that supports a young person's participation have to be given in an age-appropriate manner, both orally and in writing. In a cross-border trial, that information has to be translated into every language of the countries where the trial runs. As of 2025, the WHO's guidance on best practices for clinical trials and the recently updated Declaration of Helsinki both recognise that a young person unable to give full consent must still be involved in the consent process.
Guidance and templates
As of 2025, there is no harmonised legislation on how to prepare an assent form suitable for young people. There are hundreds of consent and assent templates that may be submitted to health authorities, and not all of them may be fully complete. With that in mind, the European network of paediatric research at the EMA and a European young persons advisory group network developed guidance that shares best practices for assent forms compliant with the high ethical standards of paediatric trials. The guidance is an overview tool for any stakeholder who has to prepare an assent form.
As of 2018, there was consensus in the European Union that assent forms should be adapted to the age and level of understanding of the children targeted, but discordance about the appropriate age of assent and about whether a child's signature was required to confirm agreement. So a writer developing assent form templates for use across multiple countries and multiple trials faces the challenges of negotiating national laws and local practices while ensuring language appropriate to aid a child's understanding of the trial.
A template can aid the development of a trial-specific assent form, but there is not necessarily a one-size-fits-all model of assent, because each child's level of understanding differs. The decision on whether the materials are suitable rests ultimately with the ethics committees whose approval is sought, so templates should be adapted on the basis of ethics committee feedback and of evidence-based learning and research.
As of 2018, the internet offered several ethically approved assent forms from which a writer could build a company template, but most of these examples were outdated and did not describe any involvement of children and young people in their development. Few of the assent forms available for download used the basic design elements of small pieces of information, meaningful illustrations or pictures, and lots of colour.
conect4children is a paediatric research network that provides examples and materials for patient education and involvement in research, along with training for professionals.
The child's age and reading level
Information about a clinical trial for children, their parents and their grandparents has to be targeted appropriately, which is particularly difficult in paediatric studies because the children involved may span a wide range of reading and cognitive ages. As of 2013, the Organisation for Economic Co-operation and Development had shown that 20 per cent of all 15-year-olds have reading difficulties.
The guidance tailors its recommendations to the age group. European regulation divides the paediatric population into four age subgroups, each with a distinctive cognitive capacity that has to be taken into account: infants and newborns from birth to two years, preschoolers from two to six, schoolers from seven to 11, and adolescents from 12 to 18. For infants and newborns no assent is expected, because it is very difficult to obtain at that age, and only the consent of parents or legal representatives is needed to enrol the child; if the infant protests through body language, that should be discussed with the parents or legal representatives. The guidance's assent recommendations are addressed to the other three age groups.
One company had two assent form templates, one for younger and one for older children, developed in 2013 when it conducted its first paediatric trial. On review in 2016, the team found scope to improve the design and overall comprehensibility of both.
Language a child can follow
Writing clinical trial information for a paediatric population is even more challenging than other lay writing. Material for children and young people requires the writer to disregard both their scientific knowledge and their best practice in writing for adults, and to optimise the work for a different generation. The task is more complex still for writers with limited personal interaction with children and young people.
Informed decision making by young people has to be ensured through communication they can understand. The language has to be adapted to be age appropriate for the different age groups, and writers are encouraged to use plain language, a narrative approach and a reassuring, friendly tone.
Like other participant documents, assent documents for children must be constructed to be understood. A child may not understand the phrase "I have been informed that I may leave the study at any time without affecting my medical care and relationship with my doctor" but will understand "If you do not want to be in this study, you don't have to. If you say you want to be in it and then change your mind, that's OK. All you have to do is tell us. No one will be mad at you or upset with you if you don't want to be in it." An investigator's brochure or a study protocol is worded so that the study personnel and the FDA can understand it, but study documents for minor children need to be worded differently. Words and phrases that have more than one meaning for children, such as study, trial and genetic makeup, are particularly difficult.
Even a text written for children, such as the patient information in a paediatric study, must take into account that the children reading it are likely to have become experts in their own disease.
Length and layout of the assent form
The guidance's recommendations cover format and content. On format, it advises keeping the form to three pages at most, with a clear layout, concise content, a glossary for complex medical terms and a friendly, conversational tone. Visual aids and different colours can highlight the most important information or make it simpler to understand, and links may be used to save space.
The company revised the language and design of its two templates using the NIHR Medicines for Children Research Network guidance on designing patient information leaflets and INVOLVE's top tips for researchers. The redesign concentrated on overall readability while still complying with ICH GCP. Its writers recommend that materials for children use smaller pieces of information, illustrations or pictures that have meaning, and lots of colour. For younger children the team opted for simplicity, with illustrations to make the content appealing; for older children it used a series of arrows and illustrations to guide the reader around and down the page.
Content of the assent form
For schoolers and adolescents, the guidance advises that the form give the trial's EU CT number as assigned at registration and its title in an understandable form, the organisations involved, whether sponsor or investigators, a personal-data-protection statement explaining that the data will be anonymised, and a request for the young participant's own assent signature.
The form should also give general information about the trial: why it is being performed, what is known about the study drugs where it uses any, the benefits and the risks, and the overall duration. A check-up calendar is worth including, especially for the older groups. Trial procedures, tests, the voluntary nature of participation and the glossary may be useful across all three age groups. Last, the form should carry a confirmation of understanding: a declaration in which the witness and the doctor state that they provided the information in an understandable way and gave the participant time to ask questions.
Some content is especially relevant to the oldest group. Where the study drug might have unexpected effects, such as infertility or birth defects, the form should say so, together with the potential use of contraceptive medication. It should name emergencies, such as an unexpected pregnancy during the trial, which the participant should report to the doctor immediately, and it should include trial costs, compensation and insurance. Where the trial collects biological samples or performs genetic testing, the guidance advises putting that in a separate assent, where the information can be explained more thoroughly.
Before an advisory group reviewed them, the company's templates were organised as a sequence of the child's own questions (why have you asked me to help, why are you doing this study, is it okay to change my mind and do I have to take part, how many times will I need to visit, will I see the same doctor, will I be safe, who else is taking part), with bracketed placeholders for the trial-specific details.
Information materials
Information materials are advisable alongside the assent form, to explain the trial more thoroughly and in more detail. They can come as booklets, guides, animations, comics and videos, engaging tools that can be used to explain the procedures, simplify complex medical terms and walk the participant through each medical procedure. They also encourage communication and give the young participant more confidence about what to expect during the trial. The assent form and the information material complement each other and should be considered as a whole.
The examples below were designed, together with their assent forms, for real clinical trials and for different age groups. Two organisations that promote paediatric research were primarily involved in designing their information materials.
Preschoolers. The booklet is a comic about a bunny, told in very short dialogues, in which an elephant doctor explains each medical procedure the bunny goes through. It uses colourful illustrations, concise dialogue and a storytelling approach, which is normally the best way to inform this age group.
Schoolers. The booklet again uses colourful illustrations and a friendly doctor guide, and adds background on the medical condition being investigated. In place of a standard glossary it uses a visual guide of images with short text. Its general information explains what medicines are for, what a trial is and why it matters, and why this participant is being asked to take part. The check-up calendar from the guidance is drawn as a roadmap resembling a board game, so the participant can see every check-up ahead. Unwanted effects are included: at this age children have the maturity to understand the risks they might face, so transparency with them is very important. The tone is reassuring, because the medical examinations these children go through can be intimidating. The closing pages restate that participation is voluntary ("it's up to you to decide"), which underlines that the power to assent or dissent lies with the participant, and give the sponsor information.
Adolescents. The booklet was written for a study of how to prevent myopia from worsening. It carries more text than the other two and is more descriptive, and its study-visit calendar is a clear table. A clear header names each section. The pregnancy emergency named in the guidance appears here as a direct instruction to call the doctor immediately if an unexpected pregnancy occurs. A frequently asked questions format delivers concise messages. The last part is the GDPR policy, where the text is quite dense; it reassures the participant that the data will be anonymised and that nobody apart from the researchers will have access, and points to the trial website for more information. The sponsor information is also included, and the last pages are left for notes, so the participant can add their own thoughts and the booklet feels personal to them.
Recording assent or dissent
As of 2012, the parents legally had to sign the informed consent, and whether one parent or both should sign was a serious difficulty, because the requirements differed from country to country. From around school age, children themselves had to be informed and should also, as a symbolic act, sign an assent.
As of 2013, adolescents and children in China were in practice also recommended to sign the informed consent form, with no age threshold specified for their signature as long as they could understand the form.
In the preschool example the assent is a single page in the booklet's style: the bunny asks whether the child wants to take part and invites them to put a cross on yes or no and add a signature.
The schooler assent runs to two pages and leads with the main trial information and illustrations. A doctor character then recaps the booklet's key points as a yes-and-no checklist before the signature. That page can also suit preschool-age children, who can simply be invited to put a cross in the box.
The adolescent assent runs to three pages. It opens with the identification number and trial-specific information. It recaps the key points as a checklist covering the explanations given, the confidentiality of the data and the free nature of participation, and then invites the participant to tick yes-or-no checkboxes and sign.
Both older forms carry a confirmation of understanding. Following the guidance, the schooler form has a declaration by a witness and a declaration by the doctor stating that the participant was given time to ask questions. The adolescent form ends with the doctor's declaration that the participant was given enough information and enough time to ask questions.
Review by a young persons advisory group
The involvement of children's advisory groups is recommended to overcome the challenges of writing for children and young people. As of 2018, such partnering was newly emerging in the pharmaceutical industry and often daunting for medical writers to undertake. Medical writers should not be discouraged from it. Involving advisory groups benefits the paediatric clinical trial process through potential participants' improved understanding of the trial materials, and can in turn improve medical writers' lay writing skills.
The guidance's recommendations incorporate input from young members. Young persons advisory groups also gave input to the design of the information materials in the examples above.
The company's team, recognising that as adults they were not experts in how children and young people think and process complex information, took its revised assent forms to the NIHR GenerationR young persons advisory group. The group assessed the two assent forms, written for children with chronic and debilitating conditions, and a consent form the company had written for parents. On 3 December 2016, at the group's meeting at the NIHR Alder Hey Clinical Research Facility in Liverpool, thirteen children and young people aged 13 to 19 reviewed the forms for overall comprehension, including design, format, clarity and readability.
All the reviewers felt the information in both forms was sufficiently lay for children and young people to understand, but they suggested drastic improvements to the design of both, to aid overall comprehension and make the forms more user-friendly. For younger children they suggested "cute animals instead of people" to make the information more reader-friendly. The team, from its experience in clinical research, at first felt this would suggest animal testing, but the group explained that younger children would not necessarily be aware of animal testing. For older children the group found the layout with arrows confusing and suggested instead a design based on colourful sticky notes and stickers pinned to a notice board.
The review also changed the signature page. The group raised an issue about the need, under ICH E11, for a child's signature on the assent form. Both forms initially used a traditional consent-form template with the ethical elements for signature tailored for assent, such as "I understand I can stop the study at any time". For older children the group altered some of the wording so that it was understandable. For younger children it was concerned that they would be unable to understand the elements of assent and provide a signature, and proposed a happy face with a corresponding tick box to acknowledge assent and a sad face to acknowledge dissent.
In the parents' consent form the group pointed out unnecessary repetition, and the templates were adjusted accordingly.
Once the redesign was complete, the team sent the templates back to the group to show the young people how their ideas and suggestions had been incorporated. The Flesch-Kincaid scores of the revised templates were in line with the reviewers' view that the wording was lay enough, but the overall design of the draft templates affected their suitability. Without the group, the team could have assumed that younger and older children would understand the trials, yet it is plausible that the children would not have engaged with the material, resulting in dissent or potentially in withdrawal after enrolment.