What Is Patient and Public Involvement (PPI) in Research?

What Does It Mean to Involve Patients and the Public in Research?

A clinical study recruits 300 patients. Another research team invites six patients to help decide which outcomes should be measured, revise participant information, and discuss how findings should be communicated. Both projects involve patients, but they are involving them in fundamentally different ways.

In the first case, the patients are taking part in the study as research participants. In the second, they are helping shape the research itself. This second relationship is what is usually meant by patient and public involvement, often abbreviated as PPI.

The distinction matters because PPI is sometimes used loosely to describe almost any contact between researchers and the public. Recruiting participants, presenting findings at a public event, and working with patient partners can all be valuable activities, but they are not the same thing.

PPI Means Doing Research With or By the Public, Not Simply About Them

What Patient and Public Involvement Actually Involves

The defining idea is research done “with” or “by” the public

A widely used definition from the UK's National Institute for Health and Care Research (NIHR) describes public involvement as research carried out “with” or “by” members of the public rather than “to”, “about”, or “for” them. The distinction shifts patients and members of the public from being solely the subjects or recipients of research toward having an active role in shaping it.

That does not mean researchers hand over the entire study. It means public contributors have opportunities to bring their knowledge, experience, priorities, and judgment into relevant research decisions.

A patient might notice that an outcome researchers consider clinically important does not capture what most affects everyday life. A caregiver might identify a burden in a proposed study procedure that researchers have overlooked. A service user might recognize that participant information is technically accurate but difficult to understand.

PPI provides a way for this experiential knowledge to contribute to the research process alongside methodological, clinical, and other forms of expertise.

Who does “the public” include?

In NIHR usage, “public” is broader than people with no connection to healthcare. It can include patients and potential patients, carers, people who use health and social care services, people from relevant communities, and organizations representing people who use services. People with lived experience of health conditions may therefore contribute to PPI whether or not they are currently receiving care.

Which contributors are relevant depends on the research. A study concerning dementia care may benefit from perspectives from people living with dementia and carers. Research on adolescent health may require meaningful ways of involving young people. A public-health study could need perspectives from communities affected by the issue rather than only patients receiving clinical services.

This is part of the broader task of deciding who has a meaningful stake in a research study. PPI provides a particular framework for involving some of those stakeholders in health and social care research.

PPI is different from research participation

This is probably the most important distinction to understand.

NIHR resources explicitly distinguish involvement from participation. Participation concerns people taking part in a study; involvement concerns active partnership in the research itself.

A patient completing a quality-of-life questionnaire is therefore participating in research. A patient who helps researchers decide which quality-of-life outcomes should be measured is involved in the research.

The same individual may sometimes perform both functions, but the roles remain conceptually different. The distinction between research participants and research partners should therefore remain clear when planning and reporting PPI.

PPI is also different from public engagement

The words involvement and engagement sound similar in ordinary conversation, but they can have more specific meanings within this research tradition.

NIHR sources distinguish public involvement from public engagement, with engagement encompassing activities through which research information and knowledge are communicated or shared with the public. Some contemporary NIHR resources describe engagement more explicitly as an interactive, two-way process, so terminology should be checked within the framework being used rather than assumed to be universal.

The three activities can also complement one another. Someone might first learn about a project through engagement, later join an advisory group as a public contributor, and separately be eligible to participate in a study.

PPI can begin before the study has been designed

Public involvement does not have to wait until researchers have completed the protocol. In fact, involvement can be particularly consequential when it occurs early enough to influence the assumptions on which a study is built.

Public contributors may help identify topics or questions that matter to patients and communities. They can challenge whether researchers have chosen meaningful outcomes, identify practical problems in proposed methods, or question assumptions that would otherwise remain embedded in the design.

This is why PPI may extend from identifying research priorities through design, study delivery, interpretation, dissemination, implementation, and research governance. NIHR resources provide examples ranging from identifying research questions and developing materials to steering-group membership and undertaking elements of research.

The broader question of which stages of research stakeholders can contribute to therefore has no single fixed answer. Their role should follow from the purpose of involvement and the contribution they can meaningfully make.

PPI does not require public contributors to do everything

Meaningful involvement should not be confused with maximal involvement. A public contributor does not have to participate in every meeting, understand every technical detail, or share authority over every decision for PPI to be genuine.

In one project, patients may make their most useful contribution when selecting outcomes and reviewing participant materials. In another, public contributors may become co-applicants, sit on management or steering groups, help conduct interviews, interpret findings, or contribute to dissemination. NIHR resources recognize this range of possible roles.

The important question is whether the role has a clear purpose and whether contributors have a realistic opportunity to influence the aspects of research for which their involvement is being sought.

Good PPI depends on how the partnership works

Simply creating a patient advisory group does not guarantee meaningful involvement. The quality of the relationship matters.

The UK Standards for Public Involvement identify six areas associated with good public involvement: inclusive opportunities, working together, support and learning, communications, impact, and governance. These standards emphasize accessible opportunities, mutually respectful relationships, appropriate support, two-way communication, attention to the difference involvement makes, and public involvement in decision-making and leadership.

These principles have practical consequences. Public contributors may need accessible documents, explanations of technical concepts, flexible meeting arrangements, reimbursement or payment, preparation for particular tasks, and enough information to contribute confidently. Researchers may likewise need to learn how to work productively with experiential expertise rather than expecting public contributors to adapt entirely to academic conventions.

PPI should not be treated as a guarantee of better research

There are good reasons for involving patients and the public, but PPI should not be described as though adding public contributors mechanically improves every study.

The value depends on who is involved, what they are asked to contribute, when they become involved, whether their perspectives are relevant, how disagreements are handled, and whether the project can genuinely respond to their input. A poorly supported advisory group brought in after major decisions have already been made may accomplish very little.

PPI can also reproduce inequalities. Researchers may repeatedly recruit contributors who already understand academic systems, have flexible schedules, speak confidently in professional meetings, or belong to established patient organizations. Those contributors can offer valuable perspectives, but their accessibility to researchers should not be mistaken for representation of everyone affected by the issue.

Inclusive involvement therefore requires researchers to consider whose perspectives are missing, what barriers prevent participation as partners, and whether the structures of the project privilege some voices over others.

PPI overlaps with broader participatory approaches, but the terms are not interchangeable

PPI belongs to a wider family of approaches concerned with involving people beyond the conventional research team. It can overlap with stakeholder engagement, co-production, co-design, participatory research, and community partnership.

These concepts should nevertheless not be collapsed into synonyms. Community-based participatory research, for example, is generally framed as a collaborative research approach involving community partners and particular commitments concerning partnership and the production of knowledge. Co-production similarly carries expectations that may go beyond what a project means when it reports PPI.

Describe what people actually did rather than assuming that one participatory label proves the presence of another.

What PPI Might Look Like in a Health Research Project

The older adults and carers are not merely being asked about their experiences so that those answers can enter a dataset. They are using their experience to influence how the research is designed and conducted. That is the defining feature of PPI.

If some of those individuals separately enroll in the study and provide research data, they may occupy both participant and public-contributor roles. The project should distinguish those roles rather than treating all of their activities as the same form of involvement.

Common Misunderstandings About PPI

Plan PPI Around Decisions That Public Contributors Can Actually Influence

If you are considering PPI, begin with the research rather than with a requirement to “have PPI.” Identify where patient or public knowledge could change how the project is understood, designed, conducted, interpreted, or communicated.

For substantial involvement, consider accessibility and inclusion from the beginning. Ask whether meeting times, language, technology, payment arrangements, institutional procedures, or expectations about academic communication make it easier for some people to contribute than others.

Also plan how you will respond to input. Contributors should not have to wonder whether their comments disappeared into a meeting transcript. Explain which suggestions affected the research, which could not be implemented, and why.

If partners are contributing significant time and expertise, determine how community or patient research partners should be compensated. If their intellectual contributions extend to scholarly outputs, assess whether those contributions qualify for authorship under the criteria applicable to the publication.

Before Planning Patient and Public Involvement

Frequently Asked Questions About PPI in Research

PPI Makes Patients and the Public Partners in the Research Process

How to Cite This Guide

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