‘A commitment to Equality,Diversity and Inclusion’: a conceptual framework for equality of opportunity in Patient and Public Involvement in research

Abstract

Many research institutions and funders have recently stated their commitment to actively support and promote ‘Equality, Diversity and Inclusion’ (EDI) in various aspects of health research including Patient and Public Involvement (PPI). However, translating this commitment into specific research projects presents significant challenges that existing approaches, practical guidelines and initiatives have not adequately addressed. In this paper, we explore how the lack of clear justifications for the EDI commitment in existing guidelines inadvertently complicates the work of those involved with PPI and we stress the need for conceptual clarity for any EDI effort to yield meaningful results. Our focus centres on the first principle of the EDI discourse, ‘equality’, particularly in the form of ‘equality of opportunity’ as outlined in current guidance provided by the National Institute of Health Research in the United Kingdom. We examine challenges related to justifying and implementing a general, unspecified commitment to equality of opportunity and explain that this reflects a lack of consensus regarding the moral value of PPI in research – a profound problem that remains unaddressed. We then discuss how the presence of several opposing moral perspectives on PPI, makes determining the most appropriate way of addressing barriers to involvement complex and controversial, raising ethical implications for the work of health researchers, PPI specialists and coordinators. Finally we make suggestions on how future research can enrich the concept of ‘equality of opportunity’ in PPI and improve practice. While our primary focus is on the NIHR, a strong advocate of PPI in research, this analysis will point to normative and ethical considerations that may be relevant to other research institutions and funding organisations aiming to promote equality of opportunity in their public and patient involvement strategies.

A commitment to EDI: The case of NIHR-sponsored research

Patient and public involvement (PPI) is becoming an increasingly important feature of health and social care research internationally (Price et al., 2018). In the United Kingdom, as part of the UK policy reform, the National Institute for Health Research (NIHR) adopted a strong policy approach making patient and public involvement a strategic priority (INVOLVE, 2012) and a well-established practice in all types and aspects of research. By aiming to realign research around the needs of those it serves, based on their experiences and designed ‘with and by’ members of the public rather ‘on their behalf’, this active involvement in research differs from passive participation in clinical trials. It means that patients, potential patients, carers, health and social care service-users, their representatives and members of the public can influence research by sharing their unique perspectives, being involved in decisions or becoming research team members (NIHR, 2018).

PPI has evolved into a world-leading practice in all studies funded by the NIHR with the aim to extend research’s reach to communities where it can have the most profound impact (NIHR, 2006). This involves engaging a diverse spectrum of patients, the public and caregivers at every stage of research, spanning various domains of health and care research, including clinical, public health, health services, social care, innovation, technology and global health. Consequently, this evolution has given rise to a wide array of PPI practices, ranging from early-phase studies to large-scale clinical trials, employing a diverse range of PPI methods, from reviewing informed consent documents to actively co-designing and co-producing research.

Yet, despite its prominent role, PPI in NIHR-sponsored research is perceived by some as exclusive, often involving the same types of people (Kerr et al., 2009) and not representing the diversity of the population as a whole. In the first review by the NIHR of its public involvement work and the first of its type internationally (Price et al., 2018), the submitted evidence identified concerns that current PPI strategies did not fully meet the requirements and goals of equality legislation and that opportunities were not accessible to the wider population (NIHR, 2020a). Concerns that unequal access to PPI may reinforce inequalities and worsen discrimination were also reported (NIHR, 2020a).

To address barriers to involvement in research, and as part of a broader initiative to foster an inclusive environment and a healthy research culture more generally, the NIHR recently stated its commitment to actively support and promote ‘Equality, Diversity and Inclusion’ (EDI) in research (NIHR, n.d.b). ¹ Based on the NIHR guidance, Equality, the first principle of EDI discourse, refers to equality of opportunity and directs that a full range of relevant people and groups have equal opportunities to get involved in research. The term diversity refers to all obvious and invisible forms of difference in individuals (such as social status, ethnicity, ability to use health and social services, etc.) which should be equally respected and valued (NIHR, 2020b). As a range of these differences have been considered as barriers for some people and groups to be actively involved in social life and research, a commitment to inclusion aims to address this problem by advocating that deliberate action should be taken to create environments where the needs of different people are met, and everyone is able to achieve their full potential (NIHR, n.d.b).

The NIHR’s commitment to EDI succeeds in communicating a concrete thesis against discrimination, elitism and bias in research; ‘. . .we will endeavour to understand the causes of any inequalities and barriers to diversity in NIHR training, research and delivery, and understand the interventions that work to address these’ (NIHR, n.d.a). However, the specific implementation of this commitment in individual PPI research projects remains unclear. This lack of clarity is particularly evident in the NIHR’s most recent publication, the NIHR Research Inclusion strategy (NIHR, 2022), which neither explicitly justifies EDI in PPI nor references it as extensively as previous publications and policy documents in this area.

Implementing an unspecified commitment to equality, diversity and inclusion presents significant ethical challenges for those involved in PPI that, to date, haven’t been adequately considered or addressed. These challenges contribute to and exacerbate existing ethical issues faced by PPI, including conflicts in protocol design between researchers and PPI contributors, biases in recruitment, power dynamics and complexities related to research implementation and dissemination (PiiAF; Bagley et al., 2016), which despite their importance, have only partially been considered in the PPI literature. Current discussions predominantly focus on practical aspects related to the sustainability and quality of PPI methods (Condon et al., 2019; Golenya et al., 2021; Squires et al., 2020) leaving conceptual questions, such as the precise goals of PPI, largely unaddressed. Moreover, while there is a substantial body of literature on conceptualising epistemic injustice, the current emphasis on the epistemic aspect of this injustice has limited the examination of the fundamental characteristics that define it as inherently unjust (Byskov, 2021), overlooking important ethical considerations. As we discuss below, these gaps further complicate current efforts to promote EDI, particularly when a wide range of studies and PPI methods are involved, such as in NIHR-sponsored research, and underscore the pressing need for further work to examine and address them.

In this paper we present a clear set of considerations and reasons that can contribute to a better understanding of the complexities associated with a commitment to EDI in patient involvement in research to inform existing policies and strategies intended to advance PPI. As such, our aim is not simply to provide descriptive clarity (as seen in Greenhalgh et al., 2019), but to examine the related ethical and practical implications that have broadly been overlooked. Though our focus is on the NIHR, a strong advocate of PPI in research, this analysis will point to normative and ethical considerations that hold value not only for NIHR-sponsored research, but also provide a foundation for a more comprehensive understanding of equality of opportunity and PPI in other contexts. As more research institutions and funders aim to actively support and promote EDI in PPI today (e.g. Cancer Research UK (n.d.), or the Social Sciences and Humanities Research Council), having a clear understanding of these challenges and finding ways to address them is particularly important.

In the next sections, we discuss challenges regarding the justification for and implementation of a commitment to EDI in PPI by focusing on equality, the first principle of the EDI discourse. We consider equality in the form of equality of opportunity based current guidance by the National Institute of Health Research in the United Kingdom. We make three arguments: First, that there is lack of clarity regarding the conceptualisation and justification of equality of opportunity in PPI, which reflects a lack of consensus regarding the moral value of PPI in research. Second, that the aim to improve research relevance and address social marginalisation and community disempowerment encompasses ideas that may contradict each other and thus make the application of a general, unspecified commitment to equality of opportunity difficult. Third, that due to several opposing moral perspectives on PPI, deciding what is the most ethical way of addressing barriers to involvement is complex and controversial. We briefly discuss some ethical implications of this problem for the work of those involved with PPI in research. We then make suggestions for how future research can enrich the concept of equality of opportunity in PPI to improve practice.

Equality of opportunity in PPI: How should it be understood?

The NIHR’s commitment to address barriers to inclusive involvement and its related initiatives (e.g. race equality training, or the INCLUDE project) that aim to improve the inclusion of under-served groups in research, place equality in a prominent position within the EDI discourse. Equality seems both to attach moral value to NIHR’s initiatives aiming to promote diversity and inclusion, and to indicate the way in which inclusion and diversity should happen. Organisations that work to promote diversity and increase inclusion argue that involving people from diverse backgrounds requires genuine commitment to equal opportunities and the implementation of effective practical measures (World Economic Forum, 2021).

The NIHR guidance clearly states that there are risks when people from diverse backgrounds do not have equal opportunities to get involved with research and advises researchers to reflect upon the full range of diverse experiences and perspectives that will give added value to their studies (NIHR, 2020a). However, what these risks are and how they relate to the specific purpose of PPI are not clearly explained. For instance, one statement seems to support the idea that a lack of equal opportunities in PPI may affect the relevance of research for those excluded or absent and thus compromise its social value: ‘Apparent exclusion or lack of diversity in those becoming actively involved is unlikely to be intended. . . . The risk is research will not benefit from the insights and experience of those most affected and who potentially have a lot to offer’ (NIHR, 2020a: 10). Other statements emphasise the importance of including those often neglected by mainstream society, without making any reference to research relevance, reflecting the idea that the more inclusive a PPI group is the more related to the idea of social equality, for example, ‘Research [should be] pursued with the active involvement of service users and carers including where appropriate, those from hard- to- reach groups such as the homeless’ (NIHR, 2018:16). Important questions remain unanswered: Is unequal access to PPI morally problematic simply as inequality, for example, because it is accessible only to those who have the means to be involved (such as people with an existing connection with the organisation)? Or is it morally problematic insofar as it is likely to prevent a study from being applicable to certain groups of patients? When is the absence of a marginalised or unrepresented group from PPI wrong?

The lack of clarity regarding a commitment to equality in PPI is not only evident in published reports for NIHR-sponsored research, but also in guidance documents issued by several organisations (for instance, Cancer research UK; UK’s Alzheimer’s Society; the Australian National Health and Medical Research Council; McPin Foundation), all of which aim to promote EDI. These documents focus on strategies to overcome barriers to diversity and inclusion (such as improving the logistics of participation, and increasing financial compensation) and suggest flexible and innovative ways of working with PPI contributors. However, they do not clarify the reasons why equality in PPI should be pursued.

It could be argued that having a concrete account for promoting equality of opportunity in PPI is not necessary. To support a healthy and inclusive research culture, as the NIHR and other organisations inspire, we do not necessarily need to agree upon a specific moral justification regarding equality of opportunity. Regardless of one’s approach to this issue, the importance of an inclusive research environment is not contested, nor is the view that intentional exclusion of a potential PPI contributor because of their group membership or personal features should be condemned (unless their involvement is incompatible with the aims of the research). This commonly accepted conception of equality of opportunity, also known as Formal Equality of Opportunity, determines that the selection of PPI contributors advances the aims of PPI in research by non-discriminatory means and is the least demanding conception of equality of opportunity that can, in principle, be satisfied in any research. Following this view, it could be argued that the obligation to not add to inequality or unjust exclusion in PPI is fulfilled if Formal Equality of Opportunity is satisfied.

However, there are several limitations with this approach. Although people from all sectors of society formally have equal opportunities to get involved with research, several factors such as lack of information, training or time and cultural barriers can deprive certain groups of genuinely equal opportunities to participate. To achieve genuine equality of opportunity, funders, researchers, PPI specialists and coordinators need to ask critical questions when designing and implementing their PPI strategies such as ‘What do we mean by equal opportunities in PPI?’ and ‘Why should equal opportunities be pursued?’. The following paragraphs elaborate on these complexities.

Ethical justifications for PPI in research and competing rationales for a commitment to equality of opportunity in PPI

The NIHR guidance recognises that the reasons for involving members of the public in research may not always be well-defined and can overlap with each other (NIHR, 2006). However, while flexibility in approach is valuable, this presents some significant challenges. Different ethical justifications for PPI embody distinct normative understandings of the value of PPI in research. These understandings have implications for whom should be involved, how involvement should occur and how to understand and implement a commitment to equality of opportunity in PPI in practice. To further clarify this point, let us consider the two primary rationales in support of PPI in research and their differences.

The outcomes-based rationale for PPI in research

The outcomes-based rationale considers PPI in research as instrumentally valuable for the improvement of health and social care services. By living with the condition under study and/or using the health services, PPI contributors have different experiences and knowledge to those of the researcher. Such experiences and insights are a valuable tool to improve specific aspects of research conduct and to achieve more patient-centred results (Lignou et al., 2019).

The outcome-based rationale for a commitment to equality of opportunity in PPI relies on the expectation that a diverse and inclusive PPI will lead to diversification and inclusiveness in research, and thus to research outputs that reflect the heterogeneity of the patient population. In health services research, for instance, opportunities for involvement need to be accessible to the wider population so that the experiences and perspectives of PPI contributors can help produce results that are more relevant and responsive to the population as a whole. Researchers who conduct health systems research, but rely only on the experiences and views of those with an existing connection to the organisation, take a problematic PPI approach because they are less likely to consider the broader population’s needs or to capture critical issues, such as access to care barriers. Likewise, the input from seldom-heard or underrepresented groups is needed to help researchers identify and address otherwise unidentified issues faced by less-heard patient communities (Ashcroft et al., 2016; Brett et al., 2014; Crowe et al., 2015; Domecq et al., 2014).

For proponents of the outcomes-based rationale, unequal access to PPI in research due to lack of resources (e.g. financial means or training), or the absence of those who are often overlooked and ignored by mainstream society in PPI, are not moral concerns in and of themselves unless they are related to the aims of the research. As the outcomes-based rationale argues for an instrumental value of PPI in research, lack of equal opportunities in PPI is problematic only if the research (process and outcomes) stands to privilege certain patient groups. Equal opportunities for involvement of those who are usually excluded from PPI may have important positive impacts, such as the empowerment of marginalised groups (Bedwell et al., 2020) and the restoration of public trust (Burgess, 2014). However, according to the outcomes-based rationale, these are considered as ancillary benefits.

Considering PPI as instrumentally valuable for reasons directly relevant to the epistemic aims of research suggests that a rigorous approach is necessary to justify a commitment to equal opportunities in PPI. Current evidence shows that PPI has limited merits, with a positive impact being reported on some aspects of research (Bagley et al., 2016). Based on the outcomes-based rationale, a commitment to promoting genuinely equal opportunities in PPI cannot be supported for all types or stages of health research. Furthermore, researchers need not be concerned with the involvement of traditionally discriminated groups if those groups are not likely to advance their research aims. It is important to acknowledge the limitations of this stance, particularly concerning the scarcity of data due to historical marginalisation and exclusion from research that some groups and communities have experienced.

The rights-based rationale and emancipatory justifications for PPI in research

In contrast to the outcomes-based rationale, proponents of the rights-based account argue that the issue of who should be involved in PPI rests upon ethical justifications for PPI in research (Friesen et al., 2021) that are not necessarily tied to expected research outcomes. According to the rights-based rationale, PPI in research is an entitlement that all patients/service users should hold, as it provides a route to influence change and improvement in issues that concern them the most.

Emancipatory justifications for the value of PPI in research rely upon a similar rationale; they consider PPI as morally important because it can empower people who use health and social care services. Emancipatory justifications are also less concerned with the expected research outcomes and focus on the social relations of research production and the lasting transformative effects on everybody involved (Baker et al., 2004; Beresford et al., 1997). Proponents of this view hold that researchers and their organisations have a moral duty to reduce the known power imbalances between research and patient communities, especially with oppressed and seldom-heard groups (Brett et al., 2014; NIHR, 2006; Oliver et al., 2008).

For both the rights-based and the emancipatory accounts, the absence of particular groups from PPI in research is considered as unfair and wrongful practice. As Beresford (2003) notes, those excluded from research (e.g. refugees and asylum seekers, people with complex and multiple impairments, frail older people) are usually the same groups of people also excluded from political and social life due to prejudices and discriminatory practices. The absence of those groups from PPI is considered to devalue and marginalise their experiential knowledge, described often as a form of epistemic injustice (Langton, 2010). Because of this omission, it is argued that social inequalities are exacerbated as minority groups have fewer opportunities to be heard.

Proponents of the rights-based and the emancipatory rationale for PPI consider equal opportunities in PPI as a moral imperative (a commitment that researchers and their organisations ought to honour) and do not make distinctions between different aims or types of research in which people may be involved. To realise equal access to involvement in research, they argue that it is important to shift the culture of how PPI in conventional research is defined and undertaken (Kalathil, 2013), and to focus on strategies that can include the perspectives and knowledge of people who have suffered abuse, oppression or discrimination on equal terms with other kinds of knowledge (Fricker, 2007).

In contrast to the outcomes-based rationale, proponents of the rights-based and emancipatory rationales are committed to supporting and promoting genuine equality of opportunity irrespectively of types or stages of research (Sweeney, 2005). However, due to resource constraints and/or competing professional responsibilities of health researchers, such as tight deadlines, these perspectives are often considered overly demanding and difficult to implement in practice (Lang et al., 2022).

Equality of opportunity’ and PPI strategies: challenges with implementation

The issue of what we mean by genuine equality of opportunity and why it should be pursued, as we have just seen, is contested. Depending on whether equality of opportunity is considered as a means to improve research (for instance, more patient-centred outcomes), or as a means to other ends (for instance, rectifying broader social injustices), or an end in itself (for instance, as an acknowledgment of everyone’s equal moral worth), different justifications for equality of opportunity can be supported, and their implementation can vary. In some studies, these different aims may complement each other. For instance, in research on improving health outcomes for marginalised communities, addressing issues of epistemic justice may be crucial to improve the relevance of research outcomes. However, a general approach to equality in PPI may be insufficient in cases where these values conflict or trade-offs need to be made between them. In the following, we unpack some of the complexities involved in the implementation of an unspecified commitment to equality of opportunity in PPI.

Determining morally relevant barriers to involvement

Formal equality of opportunity requires that irrelevant obstacles should not impede involvement in research. However, determining what constitutes a relevant or irrelevant barrier to involvement depends on one’s perspective of the value of PPI in research. If PPI is viewed as instrumentally valuable, then accommodations such as providing emotional support or counselling services for people with mental health challenges may only be deemed a relevant barrier if the research pertains exclusively to this population. Conversely, from a rights-based standpoint, the absence of such accommodations represents an unjust inequality, rendering it a relevant barrier for people with mental health challenges. This is because, under the latter perspective, being a member of the diverse population affected by the issue under investigation entitles one to participate in research, even if their involvement is not expected to enhance the study’s relevance. These differences often lead to disagreements and conflicts within a project. They can create tensions in relationships between researchers, PPI contributors and PPI specialists who may support different rationales and views regarding the relevance of specific accommodations or the extent of inclusivity in research.

Determining the qualifications of potential PPI contributors

Disagreements regarding what constitutes morally relevant or irrelevant barriers to PPI are closely linked to the criteria used to determine the qualifications of potential PPI contributors. A notable example can be found in patient participation within research advisory boards, where specific prerequisites, such as education and availability, are set by the role’s requirements. However, these criteria may inadvertently exclude highly motivated individuals due to their diverse capabilities and initial disadvantages. This includes those who had to discontinue their education due to financial hardships, individuals with limited availability due to caregiving responsibilities or multiple jobs, and those with disabilities or health conditions that hinder their ability to attend in-person meetings. Collecting more demographic data on individuals involved in health research, as suggested by some scholars (Keane et al., 2023), may not sufficiently address these significant challenges. Instead, these issues underscore the urgent need to grapple with essential ethical questions. For instance, should social circumstances be considered when selecting potential PPI contributors, and if so, when? These questions can influence the design and implementation of PPI strategies profoundly.

Designing appropriate PPI strategies

To achieve equality of opportunity in PPI, it is essential to adopt strategies that increase effective opportunities for usually excluded groups. One such approach is to implement positive action programs, such as providing training opportunities for individuals who lack the qualifications to join a research advisory board. This PPI strategy is justified by the belief, based on a rights-based rationale, that special preferences are needed to increase the involvement of disadvantaged groups in research and prevent the reinforcement of social divisions based on privilege. Positive action programs may also require that individuals who are typically involved are excluded until there is equal representation of underrepresented and represented groups in these positions. However, if prioritising underrepresented or disadvantaged groups is unlikely to enhance the relevance of research, positive action programs would not be acceptable for those finding the outcomes-based rationale more attractive. Such programs would violate formal equality of opportunity and consume unjustifiable resources. In contrast, based on the latter, random selection of candidates would be more appropriate and sufficient to fulfil the commitment to equal opportunities in PPI.

The appropriateness of positive action programs does not resolve the deeper challenges posed by competing views on the value of PPI. While it may be widely agreed that reasonable modifications to conventional involvement strategies are necessary to prevent the exclusion of certain groups, achieving genuine equality through positive action programs remains a matter of debate. The rights-based rationale advocates for the highest possible degree of equality among PPI contributors and the research team. Equality is achieved by involving patient representatives in the entire research process, from design to dissemination. This approach not only promotes equal opportunities for involvement, but also equal contributions to research by creating spaces where PPI contributors' knowledge is valued (Fricker, 2013). However, the outcomes-based rationale for substantive equality of opportunity does not necessarily prioritise epistemic justice. Therefore, the highest possible degree of equality between PPI contributors and the research team may not be a desirable or necessary goal for proponents of the outcomes-based rationale. They may argue that cost considerations should determine which PPI strategies are viable, and extensive PPI training that requires a significant amount of time may not be considered cost-effective, or may delay the completion of the study. PPI can be costly, logistically challenging and complicated when people face multiple barriers or exclusions. The differences in the implementation and demandingness of equality of opportunity in PPI can, therefore, have important practical implications for designing PPI strategies.

The problems described above do not suggest that values such as epistemic justice and patient-centred outcomes are not taken seriously by those who adopt either rationale. Advocates of an outcomes-based rationale may find inequalities in PPI access and social exclusion problematic, just as supporters of the rights-based approach believe that research outcomes should not necessarily be ignored. However, as we have seen, challenges within these approaches are addressed differently, and they impose different requirements and consequences for researchers, PPI specialists, PPI contributors and the research studies they are involved in. These challenges are not unique to research; they are recurring issues raised in affirmative action policies that have been extensively debated in other settings, such as employment (Kellough, 2015). Nevertheless, given the lack of clear guidance in the context of PPI, navigating these problems while simultaneously addressing other research challenges, such as meeting project deadlines, can be particularly challenging for all those involved.

Equality of opportunity in PPI and a need for clear guidance

Different conceptions of equality of opportunity in PPI are normatively distinct. Even if we were to agree on strategies to facilitate equal access to involvement, significant questions would remain around who should be involved, how they should be involved, and in which research stages they should be involved. Current efforts by the NIHR and other organisations aiming to identify inequalities and barriers to involvement are undoubtedly important. However, for PPI to be meaningful, appropriate ethical support and clear guidance are necessary to ensure that efforts to address barriers to involvement are not tokenistic and sporadic.

Such support should not be limited to addressing false beliefs through training against bias and discrimination. To respond to the challenges discussed above, researchers, PPI specialists and co-ordinators need to make decisions that require more than the avoidance of discriminatory practices in their PPI strategies; they need to consider their explicit or implicit commitments to other ideals, such as being impartial or promoting social justice, while aiming to respond to their professional duties. In many cases, patterns of inequality may be difficult to assess, and deciding which form of social inequality is most important to address can be complicated. A principled way to assess the relative importance of these values is necessary to guide decision-making. For this to be achieved, a clear conceptualisation of the ethical issues associated with the delivery of equal opportunities in PPI is needed. Equally important are studies that evaluate the extent to which a clear account of equality of opportunity in PPI aligns with the realities of PPI in different research settings.

Our aim in this paper was to contribute to the former. We do not argue for a particular way of thinking about inequality in PPI. Rather, we aim to introduce the complexity of this issue and provide a sense of the options available to guide our reflections. Our view is that instead of simply relying upon intuition or personal experiences for application of PPI, guidance should be revised to clarify the reasons for which equality of opportunity is important in PPI and how it should be understood to avoid confusion and waste of resources. In some cases, barriers to equal access to involvement may be related to factors that individuals may have little capacity to address, such as cultural barriers. These would require initiatives at the organisational level. Examples include the provision of necessary resources for the establishment of meaningful relationships with members of seldom-heard communities in research through engagement activities. Additional initiatives may be necessary that require coordinated actions from researchers, PPI specialists and community engagement officers, funders, institutions and policymakers.

The NIHR has acknowledged its current limitations: ‘The entire system will need to enhance its analytical capabilities in order to pinpoint where gaps exist and where we need to take immediate action to address systemic under-representation or barriers’. We believe that for this work to be effective, conceptual work should be part of these efforts. While empirical research could help us better understand the barriers to involvement and the challenges faced by those responsible for designing and delivering PPI approaches in various settings, philosophical analysis can assist in formulating robust frameworks and providing arguments for and against existing rationales, informed by real-world problems. In this way, we can comprehend the limitations of each claim for EDI in PPI research, the necessary trade-offs to prioritise different approaches and methods in PPI in research. Together, these streams of work can inform a more pragmatic approach to PPI that avoids exacerbating inequalities or unjust exclusion. Consequently, such work can contribute to existing guidance and help address the ethical and practical challenges that individuals involved in research may encounter while striving to fulfil a commitment to equality in PPI.

The development of PPI in the United Kingdom is the result of specific socio-political events, and it may not have the same resonance in other countries. However, the underlying ethical challenges related to efforts to provide equal opportunities for involvement may be common across borders and different research organisations. A better understanding of the complexities of a commitment to equal opportunities can provide the basis for a more comprehensive understanding of equality of opportunity and PPI in other contexts. We hope that this paper contributes to and encourages future investigation into how equal opportunities in PPI should be understood and implemented in a more consistent and theoretically rigorous manner.

Conclusion

In this paper we argued that EDI in PPI raises a number of complex ethical and social justice issues that need clarification and guidance for those engaged with PPI in research. These issues are related to distinctions between rationales for PPI that are important for understanding what form of PPI is appropriate, as well as what its aims and functions are. We highlighted aspects of the debate around PPI that remain unanswered and argued that a principled way of resolving disputed boundaries between acceptable and unacceptable exclusion of people in PPI, which set the standard of Formal Equality of Opportunity, is necessary. Ethical guidance, which recognises the complexities and trade-offs required in this context is needed to help address ethical challenges and implement involvement strategies that are fit for purpose.