Table 3 Overview of good practices, barriers, and facilitators of the included studies

Preparation

 Recruitment

Recruit involved persons, regardless of cognitive abilities [23], based on skills, different personal characteristics [13] and prior relevant experience [38]

Recruiting through gatekeepers (health professionals and carers) can result in the exclusion of less articulate or critical people [35], people with cognitive impairments [28], and people living with dementia [32]. A lack of identification with medical labels might lead to difficulties in recruitment [30]. Involvement of people with mild to moderate dementia does not imply representation of the experiences of people with more advanced dementia [33, 34], and involving carers might put carer’ experiences in the forefront [13, 32]. Lack of diversity, such as differences in ethnicity and religion, is an issue in PPI [26, 33]. Snowballing can result in less diversity [13]. Assuming “peerness” between co-researcher and interviewee based on sharing a dementia diagnosis and both being older persons is not enough [34]. Co-research might favour people who embrace a dementia identity and silence those who have a more self-maintaining stance [34]. The voluntary nature of PPI might imply that the skills requirements for performance of the involvement role(s) are not met [13]

Work alongside healthcare professionals and services to recruit people who are hard to reach [30]. Recruiting through existing networks and peer support groups is a good basis for building relationships [24, 38]. Involving representatives with different personalities and skills provides multiple unique perspectives and enhances data collection [13]

 Role description

Explore and discuss the purpose, scope, and expectations of involvement [26, 28] at the beginning and throughout the project [29]. Provide a common, but adaptable framework [28]. Offer personal and professional development opportunities [13, 32] to make involved persons’ roles more rewarding, and support involved persons holding multiple roles [32]. Co-design the role in collaboration with involved persons, taking into account skills, preferences, and goals [13], for example using a forward planning activity sheet to enable involved persons to indicate their interests [32]

Naturally evolving roles result in a lack of clarity about expectations and involvement in irrelevant topics and tasks [37]. Integrating an involvement role in predefined governance structures was difficult and panels have not always moved in line with initial researcher expectations [28]. Access to ICT when being a co-applicant, complex language and procedures used to structure involvement roles can potentially exclude experiences of persons living with dementia [32]

The identification of clear roles, activities and tasks, and expressing expectations and values ensures that involved persons feel part of the team [38], prevents ‘tokenistic’ involvement [28] and can help the involvement process [32]. It is important to understand the involved persons' motivation for involvement to ensure personal needs are met [32]

Relationships and group dynamics

Involved persons: Take time to build a mutual trusting relationship [13, 23, 34], to foster freedom of expression [33] and break down social barriers [37]. Become familiar with the strengths, limitations and what the person is comfortable with in order to maximize contribution [31, 34]. Reflect on group dynamics through a hermeneutic-dialectical process [35]

Long-term care facility (LTCF) staff: Developing a trusting relationship with LTCF staff, particularly with management and administrators, is important for involvement research in these settings to succeed [35, 36, 39]

Involved persons: Researchers need to stop making assumptions about the abilities of persons living with dementia [31]

LTCF staff: LTCFs are highly hierarchical environments [35, 39]. Distrust of management and other staff towards involvement research process can lead to drop-out of organisation [36] and low staff participation [39]

Involved persons: Allow time for socialising [29], organize social meetings/activities [37, 38] and meetings in the home of lay researchers [13]. Pay attention to difference in roles and responsibilities [38]. Meet regularly/monthly [13, 38] even when there are no research meetings to keep involved persons motivated [34]. Travel together to interviews to brief and debrief [13, 34]. Avoid being tokenistic [13] and see the person through an appreciative lens [31]. To develop a shared voice it is important, particularly for marginalized groups, to meet in a homogenous group [35] and in small groups for involved persons s to get to know each other and feel confident to express their views [29]

LTCF staff: Developing a shared vision is a condition for quality and validity [36]. A trusting relationship with board members and management can facilitate support of other staff [35, 36], inhibit reluctance to involvement, and prevent scheduling conflicts [39]. Develop strategies to motivate LTCF staff to become involved [39]

Training of academic and non-academic involved persons

Provide iterative coaching and training sessions [23, 31], based on emerging needs [13] or when lay researchers indicate an interest [37], to challenge the dominant view of scientific knowledge, increase reflexivity [36], ensure an appropriate skill set, establish understanding of the involvement process [28], and provide guidance and tactics to fulfil co-research role [32, 33]. Training on everyday ethics [31], how to build an equal relationship, reducing technical language and recruitment [28] should be offered to academic researchers [13, 23]

Training raises costs [28], is at odds with the principle of valuing experiential knowledge [37] and should not aim to make co-researchers into ‘expert’ researchers [32]

Training fosters confidence, skills, building rapport, a positive experience and will empower involved persons to engage, motivated, meaningfully and equally in the research process [13, 33, 38]

 Financial compensation

Provide financial compensation [13, 32] for travel expenses, shopping [26], attendance at meetings [25, 27] and provide print-outs to avoid printing costs [26]

Project funding for involvement compensation was underbudgeted, involved persons only received compensations for travel expenses and accommodation [27]. Resourcing of travel expenses of involved persons was an issue [28]. Assistance with transportation should have been provided [25]

Compensation serves to acknowledge the invaluable contribution of involved persons to the research [13]

Practicalities: Time, budget and setting

Plan and budget for additional administration, time, staff, and involvement activities early on [13, 28, 33, 37]. Plan extra time for involvement activities [13, 29, 34]. The setting and timing of involvement activities matter; pay attention to: social status of location, availability of disabled access, close to facilities, and ensure that the place is familiar, comfortable, and easily accessible (close to public transport and car parking) [29,30,31, 34]

Limited resources restrict the desire of involved persons to meet more often [28] and hinder sustainability of initiatives [39]. Due to time constraints, representatives only supported 20% of the interviews [38]. Some forms of involvement such as co-research and action research are more resource (competences, time, and commitment of researcher) and budget intensive than other forms of involvement and may delay the research process [13, 32, 36, 39]. The physical space of involvement activities should be considered more [33], meeting in an unfamiliar place (e.g., office) could lead to stress and more distractions (e.g., less concentration) [31]

Virtual meetings are accessible regardless of location and less time consuming [26]. Empower involved persons to ensure meetings are led by them and use staff in support roles [28]. Availability of financial resources is important to implement developed ideas [35]. Develop strategies to sustain initiatives (e.g., resident councils could facilitate resident groups) [39]. Meeting in a familiar environment allows for robust involvement and enhanced concentration for people living with dementia [31]

Execution

Planning of involvement design

Plan long-term collaboration with lay researchers early in the research [13]. Ensure ethics approval is in place [13] and when research ethics committees see co-analysts as research subjects, make certain no new data is gathered [24]. Make agreements on the confidential nature of research discussions and materials [25] and on what information is shared during co-research interviews [13, 32]. Ensure representation on research governance level [27], in steering and advisory groups [23]. Involving persons living with dementia as co-researchers can open up an empathic level of knowledge [23]. Invite co-researchers to analyse data independently, rather than verify the interpretations [33]

Need of an ethical framework for co-researchers which formalizes expectations, responsibilities, and confidentiality [23]. When interview guides are ethically approved prior to co-researcher involvement, this will limit the capacity of co-researchers to direct the interview [32]. The empathic bond between co-researcher and interviewee can have disadvantages, such as entrusting information in private [13],wanting to help the interviewee [32] and shared experiences might influence interviewee responses [23]. The involved persons-led design created the potential for conflicting ambitions of involved persons and researchers [28]

Early involvement increases confidence [13, 31], enables full involvement and time to build a trusting relationship [31]. Involve co-researchers in future work (e.g., identifying research priorities) in order to reposition people living with dementia at centre stage [23]. An emergent design facilitates co-ownership and ensures the research is responsive to the involved person’s experiences [35]. In relation to multisite involvement activities with central terms of reference, allow local adaptions to nurture ownership of the local group [28]

Academic culture and experiential knowledge

Lived experiences of people living with dementia should be central and guide development of research [23, 27]. Researchers should have an open mind, give up control, be open to having their traditional academic views challenged, not be dismissive of lay people’s views, step out of their comfort zone [13], value experiential knowledge and not make assumptions based on a deficit perspective [31]. Use a consensus-based approach [25] and maintain balance in joint decision making [23]

Use of academic jargon [13, 37], rapid pace of discussions [37], (subtle) power relations [36, 37], and difference between ‘academic time’ and ‘dementia time’ [24] can inhibit involved persons from expressing their views [13] and to tell about their world, and can make involved persons inclined to give socially desirable answers [37]. The dominance of the biomedical model in research decision making, the conventional social science research paradigm, the authority of research and adherence to ‘rigorous’ academic models can lead to undermining the contributions of lay researchers [13] and are a challenge to the impact of involvement, especially in relation to dementia studies where people are historically silenced [24, 32]. Including lay people in research meetings allows less space for academic talk (less efficient), expressing personal comments was not always appreciated [37] and lived experiences of lay researchers can clash with academic views and priorities [13, 23], which can be uncomfortobale for both lay researchers and academic researchers [32]. Some people might feel intimidated by the titles of academics [31] and having confidence to share personal experiences [13] or indicating a lack of understanding can be challenging [37]

Separating technical topics from general meetings [37], making a glossary of common terms to understand each other’s jargon [37], slow down to examine assumptions about dementia, reflect on the relationship and how power is shared [31], and a relational empowerment approach to facilitation, in which the facilitator acknowledges the other’s power and disempowerment, and adapts to fluctuations, could minimize power differentials [35]

Facilitation of involvement

Facilitation is very important [28, 35] and is a skill that needs practice [23]. Facilitation should include: managing and guiding involvement processes, ensuring equality of power, safeguarding the autonomy of involved persons [32], a non-directive approach, good listening skills, reflecting the words of involved persons, acceptance, positive regards for opinions [33], minimize control, embracing evolving process, appropriate risk assessments, offer professional support, be creative [23], allow time for repetition of information and clarification of tasks[29]. Inform involved persons how their input has shaped, guided, and made a difference in the research [31] at the beginning of meetings [26] and throughout the study [30]

Need for more time, opportunities for clarification [37] and more support of academic and lay researchers to ensure meaningful and effective involvement [13]. It takes time and effort to explain that scientific knowledge is not a pre-set prescription for change and needs to be contextualized, which requires reciprocal adequacy [36]

Involved persons have to be encouraged and reminded by facilitators that they are not research subjects [32, 33], are experts of lived experience [39], their knowledge and actions are valid and essential [36], that they can challenge research documents, and to note down thoughts [37]. This implies that facilitators reflect on their own actions and those of others involved [36]. Maintain a structured (i.e., set agenda), but informal and flexible meeting style, and ensure an efficient operation to encourage involved persons to express their views and enable their voices to be heard [27, 28]. Showing the impact of involvement is important to motivate involved persons s and to increase energy [31]. It facilitates a feeling of being taken seriously [28] and of intrinsic reward [32]. Active contribution of principal investigator was experienced as empowering [28]

Burden and support

Offer physical, emotional [13], and peer support [23] in relation to personal ageing and mortality [38]. Take into consideration potentially changing needs and deterioration in capabilities when involving persons living with dementia [30, 33] and help involved persons to find support when needed [29]. Identify individuals in the research team or an independent individual as a focal point of contact [28] whom involved persons can approach if they have concerns [37]. Involve experienced staff who have practical experience of working with persons living with dementia and their families [29], to offer guidance and support [30]

Some carers have dropped out due to caring difficulties [26]. Hearing or observing disturbing situations which sometimes resonate with involved persons’ own experiences can be distressing [13, 32, 38]. Involving only one person living with dementia in a group of people is experienced as intimidating and researchers showing compassion as disturbing [32]. Maximising contribution of co-researcher without overburdening him or her is a challenge [31]

Avoid too fast a pace for people who may tire easily [24, 29, 30] plan regular breaks in meetings [24, 25], be flexible regarding time frames for specific tasks and allow a ‘time-out’ when necessary [29]. Briefing and debriefing after co-researcher interviews [32] is important to provide emotional support [13]. Involve a larger team of persons to reduce the sense of burden and responsibility [37]. Involve carers or family members of persons living with dementia in the process to ensure support [25, 29, 30] and provide tailored support to avoid overburdening the carer [29]. Peer support is of importance to ensure wellbeing in the process [23], and meeting the same people at each session is beneficial for persons living with dementia and their carers [26]. Do not assume what the meaning of burden is or what support is needed [30, 31], treat people as individuals and ask the person living with dementia what he/she is willing to do or if support is needed [30, 31]

 Communication/information

Establish ground rules for communication [37] and follow guidance on communicating with persons living with dementia [33]. Record and take minutes of meetings to share meeting notes with the broader research team [25] and all involved persons [26]. Share all research outputs through email or handouts [26]

Too much and irrelevant or inadequate information was shared [37], this is a problem specifically when taking into account differing abilities of involved persons [23]. Video calling-related technical problems made communication difficult [37]

To avoid an overload of information, make individual agreements on the type, amount, and format of information sent to involved persons [27, 37]. Provide summaries of key points and clearly state why the information is sent [37]

 Inclusive tools

Provide pens, paper during meetings, accessible meeting materials in advance [25] and folders to organize information [37]

Use of creative visual tools should have been considered more [33]

To enable involvement of persons living with dementia use visual tools [30], such as picture word cards, storyboards and cue cards, to prompt memories [24, 34]. Modify methods and develop interactive activities to enable involvement [30, 31]. To increase visual distinctiveness, provide documents in large font [26], on coloured paper [24], with graphics and space for involved persons’ comments [25]. Provide audio-recorded notes when involved persons have difficulties with reading [26]

Translation

Findings and dissemination

Findings should be meaningful to, accessible to, serve the interest of, and benefit people living with dementia [23, 31]. Use GRIPP guidelines to report on different ways of knowing and who decides [32]

Use social media and creative/visual methods to communicate research findings with the aim of increasing accessibility and extend the discourse on representation of persons living with dementia [23]

Reflection and evaluation

Determine how success of involvement will be monitored [28]. Evaluate and reflect on impact [26], effectiveness [23] and benefits of involvement [33] and on process of collaboration [31] through: writing down experiences in reflective diaries [13], using a template or paper format to guide reflection and evaluation [38] with open-ended questions [33], and joint reflection after each session and at the end of the programme [26]

There is a need for pre-set robust evaluation measures to assess impact and success of involvement [28, 33]

Reflection and evaluation can improve subsequent sessions [26], foster self-reflection and introspective learning [23], promote personal and professional development [13], and can help to address dementia-related assumptions [31]