Guide to a good participant information sheet (PIS)

A Participant Information Sheet is often the first meaningful encounter a prospective participant has with your study. If it is confusing, off-putting, or incomplete, recruitment suffers before it has even begun. And since the ethics committee will review it carefully, a poorly structured PIS also delays the study getting started at all.

The NHS Health Research Authority outlines four sections for a well-constructed PIS, published as detailed guidance for researchers rather than a loose set of suggestions. Here is what each one should cover and why it matters.

Section 1: Title

The title page should make the study identifiable and its scope clear. The HRA framework centres on four elements: Intervention, Population, Outcome, and Comparator (IPOC).

• What intervention is being tested: a supplement, drug, device, or behavioural approach?
• What population will be involved: age range, sex, clinical characteristics?
• What outcomes are expected or being measured?
• Is there a comparator: a placebo, an established therapy, a different intervention?

These four elements together give a reviewer (and a prospective participant) immediate orientation.

Section 2: Invitation and summary

This section introduces the study. It is not the place for full detail: its job is to give enough context for someone to decide whether to read further without overwhelming them.

Cover:

• What the research involves and how it relates to people in this population
• What is being investigated and what participation broadly involves
• Who is eligible to take part
• Where the study will take place
• How long it will last

The goal is to generate interest and give enough information for an informed first impression, not to answer every possible question. Too much detail here often reduces recruitment by making the study seem more complex or demanding than it is.

Section 3: Details of what's involved

This is the comprehensive section. If the invitation summary creates interest, this is where a prospective participant gets the full picture, and it's also the section where the evidence on consent comprehension has the most to say.

Background and purpose. Explain what is already known and how the study builds on it. Avoid jargon and unnecessary acronyms. Assume the reader has no prior knowledge of the research area. This section carries more weight than it might seem to on the page. A study of 266 healthy volunteers at a phase I clinical trials unit tested recall of core study information the day after the consent process, and found participants remembered the practical details reliably (91% correctly recalled the route of drug administration, 90% correctly recalled the payment amount) while comprehension of the study's actual scientific aims was strikingly poor: only 7% could state them correctly. That gap is a strong argument for making the purpose of the study memorable in its own right, not just technically present in the document somewhere.

What participation actually involves. Be precise about the commitment required: how often, for how long, what data or samples will be collected, and whether site visits are required. Vagueness here creates mismatched expectations, which causes dropout. If the study is demanding, say so clearly and honestly.

Data and privacy. Tell participants exactly what personal data will be collected, where it will be stored, who will have access to it, and what their rights are. This includes the data controller, any third parties involved, and whether genomic or biological samples may be retained beyond the study period. In an era where people are more aware of their data rights, transparency here builds trust rather than concern.

Benefits and limitations. Be honest about what participation may offer and what it cannot guarantee. Financial compensation is legitimate and should be clearly stated. What cannot be promised is a particular health outcome: the study exists precisely because that is not yet known.

Risks. This section should not be understated or hidden in the fine print. All known risks associated with the intervention should be stated clearly, however unlikely they are. Include any risks to personal data as well as physical risks.

Special circumstances. Some populations require additional consideration: adults without capacity to consent, pregnant or breastfeeding participants, children, and others. Flag these explicitly and explain what additional safeguards are in place.

Section 4: Supporting information

Think of this as the FAQ section. Once a participant has read the detail, what reassurance and practical information would help them decide?

What happens if something goes wrong. Participants want to know they will be looked after. Describe what would happen in the event of a health problem or data concern, and who they should contact.

Right to withdraw. Make it explicit that participants can leave the study at any time, that doing so will not be questioned or challenged, and that it will not affect any healthcare they are receiving. This needs to be stated clearly and not buried.

Contact and further information. Who is sponsoring the study, who is organising it, who has reviewed it, and how can participants reach someone if they have questions? Always include a named point of contact with a reliable way to get in touch.

Structure alone won't fix a comprehension gap

Following the four-section HRA structure gets the right information into the document. It doesn't automatically mean a participant will retain the parts that matter most. The comprehension research above is a useful reminder that people tend to remember the concrete, transactional details of a study (what they'll be paid, how the drug is given) far more reliably than its actual scientific purpose. If retention of purpose matters to your study, and for anything beyond a straightforward observational design it usually does, it's worth deliberately repeating and reinforcing the "why" of the study rather than stating it once in the background section and assuming it has landed.