Background

Patient and public involvement (PPI) has become increasingly integrated in research internationally, especially in Europe and North America [1, 2]. In Europe, The United Kingdom (UK) has been on the forefront of this movement, followed by the Netherlands and Scandinavian countries (Biddle et al. 2021). People involved, other than the research team, in the research process is gaining momentum. In this context, the people involved refer to patients and public contributors who are invited to engage in healthcare research. Of importance is the inclusion of patients and their families as partners in the research process [1]. As such, patients and families have evolved from being solely the subjects of research to actively participating as partners throughout the research process [3].

PPI is increasingly being recognized by funding agencies and patient organizations as an integral part of healthcare research [2, 4, 5]. Prominent UK models have taken leading roles in the field of PPI, including the James Lind Alliance (JLA) and Priority Setting Partnerships (PSPs) where collaboration among patients, families, and clinicians is essential in order to identify research priorities [3]. Moreover, the government funded National Institute for Health and Care Research (NIHR) has played a pivotal role in advancing PPI [6,7,8,9]. Established in 2006, NIHR categorize the research process into seven stages which include identifying and prioritizing, commissioning, designing and managing, undertaking, disseminating, implementing and evaluating impact [7]. Further, NIHR uses terms such as consultation, collaboration, co-production, and user control to define varying degrees of involvement. NIHR has made substantial global impact on research and healthcare, significantly contributing to the improvement of treatment and care [10]. These initiatives closely align with the progressive and contemporary healthcare systems present in the Nordic Countries.

Earlier, PPI has been criticized for exclusivity and tokenism reducing patient stakeholders to a perfunctory role in healthcare involvement [1, 8, 9].Currently, people involved are increasingly recognized and valued as integral members of the research team [11, 12].

According to Engelstad et al., the Nordic societies represent a common neo-corporatist model characterized by a strong and active state, a high degree of labor market coordination and a comprehensive welfare state [13]. PPI is suggested to increase the cost effectiveness of research by ensuring that research outputs align with the patient groups’ needs [14].Evaluating the impact of PPI remains limited to involved patients and researchers, often neglecting to specify how PPI influenced study outcomes [15]. There is a gap in understanding how PPI is integrated into the research process, including the utilization of PPI terms, methodologies as sampling strategy and theoretical frameworks and its effects on study outcome in the Nordic countries of Denmark, Norway, Sweden, Finland, and Iceland. These countries share cultural values and healthcare systems, facilitating research collaboration. The aim of this scoping review is to explore and delineate the current state, practice, and impact of PPI in healthcare research across different specialties and patient populations within the Nordic countries.

Methods

The scoping review and search strategy was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) with the extension for scoping reviews [16, 17] and registered at the Research Registry (Identifier: research registry 7157) on September 16, 2021 [18]). We followed the five steps for conducting scoping reviews outlined by Arksey and O'Malley [19].

Step 1 identification of research questions

The research team devised the following research questions for references reporting PPI in healthcare research:

  1. 1.

    How extensively is PPI reported in healthcare research across the five Nordic countries? This includes its origin, document type, population and the represented perspectives.

  2. 2.

    What theoretical frameworks are utilized to characterize PPI?

  3. 3.

    During which stages of the research process and by means of which methods is PPI incorporated?

  4. 4.

    What are the positive and negative impacts of PPI reported in the literature?

Step 2 identification of relevant references

A systematic search was conducted across nine scientific databases to identify papers published between January 1992 and April 2023. We included empirical studies comprising quantitative, qualitative, multiple method studies or mixed methods research. The non-empirical papers included were protocols, discussion, description, and perspective papers. We searched the following bibliographic online databases: Cochrane Library (Cochrane Central Register of Controlled Trials (CENTRAL), Excerpta Medica Database (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medical Literature Analysis and Retrieval System Online (MEDLINE), PsycINFO, Allied and Complimentary Medicine Database (AMED), SCOPUS, Sociological abstract and Web of Science. Our search matrix included a modified PICO (patient, intervention, comparison, outcome) framework to structure clinical research questions that are important for the patient or population [20]. Further, PICO was also used to formulate the search strategy by identifying key concepts. This framework defined the population, intervention, and context within our primary focus areas: 1) Patient and public involvement, 2) Health research, and 3) Nordic countries. A combination of MeSH-terms, Thesaurus, indexed terms, and free text were used. An example of a search strategy from Medline is provided in Additional file 1. The following MeSH search terms were used within each of the three focus areas: (1) PPI: Patient partner, participant, consumer, user, public, patient participation, community participation, panel, advisory group, engagement, participation, collaboration. (2) Health research: Healthcare research in all care sectors, clinical research. (3) Nordic countries: Denmark, Norway, Sweden, Finland, and Iceland. Language limitations: English, Danish, Norwegian, and Swedish. Language exclusion: Finnish and Icelandic.

To identify gray literature, we conducted a systematic search of webpages for policy documents, reports, academic papers and documents, course materials, events, recommendations etc. from ministries, universities, patient organizations, funding bodies, and healthcare research platforms. Additionally, we contacted researchers from each Nordic country to help identify additional gray literature sources. Supplementary searches were carried out using manual and snowball search methods.

Step 3 selection

To comprehensively address the concept of PPI, we included references if they utilized, clarified or emphasized PPI within healthcare research across any setting in one or more Nordic countries. We included all papers irrespective of the PPI terminology used to refer to ‘people involved’ participants. However, we excluded papers that used PPI within a treatment context rather than within research. Three investigators, KD, SFH and STL individually screened the identified references and determined inclusion. KD, SFH and STL individually excluded non-relevant references by reviewing titles and abstracts. References identified as relevant by either reviewer underwent full text reading by KD and STL. The references were categorized as “included”, “unclear” (for discussion) or “excluded”. In case of disagreement a fourth senior researcher (MJ) provided consultation. Covidence software program (2023) was used for screening process [21].

Step 4 chart and extract the data

Papers from the systematic search in Covidence were extracted by using the NIHR framework (identifying and prioritizing research, commissioning research, designing and managing research, undertaking the research, disseminating research, implementing research, and evaluating impact) was additionally used in the extraction [6] and the Guidance for Reporting Involvement of Patients and the Public Short Form (GRIPP2-SF) [22]. We used the short version of the guidance (GRIPP2-SF), which can be used when reporting public involvement in any study, rather than  the long version (GRIPP2-LF), which is used when the study is mainly about public involvement in research [23]. We therefore modified to include additional categories: type of document, study design, study population, PPI term, participants, theoretical underpinning. Table 1 provides an overview of the modified GRIPP2-SF. To refine the modified GRIPP2-SF three papers were pilot tested prior to final inclusion. The content of the included references was assessed according to the modified GRIPP2-SF by KD and STL individually before consensus decisions were made. In case of disagreement discussions were held with MJ to reach resolution.

Table 1 Adapted guidance for reporting patient and public involvement, modified guidance for reporting involvement of patients and the public short form
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Step 5 collate, summarize, and report the results

We present the results in a narrative format, supplemented with tables and figures, and organized to address the five research questions. In addition, the findings are categorized according to reference type, including research studies, non-empirical papers, and gray literature sources. If terms of PPI participants being used appear similar, the research group discussed how to summarize the terms to create a more simplistic overview. We defined public involvement as anyone else being involved than patients, e.g. families, cares, healthcare researchers and other stakeholders.

Results

We included 53 papers from the scientific databases and three papers from gray literature, incorporating a total of 56 papers in this review as illustrated in Fig. 1. All 56 papers are presented in Table 2. Further, Table 3 displays policy documents and other non- scientific sources that were identified through gray literature searches. In the following section, we provide an overview of the types of evidence, documents, and other materials available regarding PPI in healthcare research in the Nordic countries.

Fig. 1
figure 1

PRISMA flowchart visualizing the overview of the inclusion and exclusion of papers in the systematic screening process

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Table 2 Characteristics of the included papers (n = 56) from the systematic literature search extracted with the use of a modified GRIPP2-SF
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Table 3 Characteristics of sources (n = 56) from the gray literature search based on origin and institutions
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Characteristics of empirical and non-empirical papers

Thirty-nine papers (70%) were empirical studies that applied PPI in healthcare research and 17 (30%) were study protocols or non-empirical papers that reported on aspects of PPI. Papers were published in 2006–2023, and first authors were affiliated with Denmark (n = 20), Norway (n = 18), Sweden (n = 16), Finland (n = 2), and Iceland (n = 0). Distribution of the included papers in relation to type of document is presented in Fig. 2.

Fig. 2
figure 2

Distribution of the included papers (n = 56) in relation to categorization based on origin the categorization was performed in relation to how the authors of the papers explicitly defined their own paper

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Among the 39 empirical papers, 26 (67%) were qualitative [15, 24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48], four were case studies [49,50,51,52], five quantitative [53,54,55,56,57], and four multi-methods studies [58,59,60,61]. The study populations from the empirical papers were patients with cancer (n = 8) [15, 27,28,29, 45, 51, 59], mental health illness (n = 8) [34, 35, 39, 42, 46, 49, 50, 61], cardiovascular disease (n = 2) [24, 54], kidney failure (n = 1) [52], traumatic brain injury (n = 1) [38], reproductive dysfunction (n = 1) [30], women with prior gestational diabetes mellitus (n = 1) [43], older adults and geriatric disorders (n = 7) [25, 26, 36, 40, 47, 56, 57], stroke (n = 2) [53, 55], ankylosing spondylitis (n = 1) [44], persons living with diabetes (n = 1) [60], and patients with rehabilitation needs (n = 2) [31, 48]. In four studies, no specific disease population was described [32, 37, 41, 58]. In 21 studies, solely patients were involved [27, 29, 30, 34, 35, 39, 40, 44, 45, 47, 48, 51, 52, 55,56,57, 61,62,63,64,65], six studies involved public [32, 36, 38, 42, 46, 58], 19 studies involved a combination of patients and public [15, 24,25,26, 28, 31, 41, 43, 49, 50, 53, 54, 59, 60, 66,67,68,69,70] and ten studies did not report whether they used patients, public or both [2, 33, 37, 71,72,73,74,75,76,77].

Of the 17 non-empirical papers, six were study protocols that utilized PPI methods, including a study with an exploratory and participatory design to improve resilience in healthcare [68], a qualitative study to identify and prioritize future cancer research agenda [67], a meta-epidemiological study investigating PPI in an intensive care setting [78], a quasi-experimental cohort research study on nurse-led consultations [64], a multiple method study to develop a core outcome set for intensive care unit patients [66] and a large-scale panel study evaluating PPI awareness in aging and healthcare research [70]. The remaining eleven non-empirical papers provided diverse perspectives on PPI [2, 62, 63, 65, 69, 71, 73,74,75,76,77]. Tangvald-Pedersen and Bongaardt offered an ideological perspective, describing participatory research in mental health within three ideologies, liberal, emancipatory, and caring, to balance demands of science and social relevance [76]. Beedholm and Frederiksen took an institutional perspective, discussing contextual and structural factors that impact use of PPI and introduces the concept of ‘patient logic’ [73]. Natland et al. examined PPI from an epistemological perspective, discussing how it affects knowledge production [75]. Kjeken et al., Sand et al., and Staats et al. provided methodological perspectives on PPI, describing research priorities, debating better ways to develop and evaluate PPI, and suggesting a framework for patient and informal caregiver participation in the research process, respectively [2, 63, 69]. Iwarsson et al. took a pragmatic viewpoint, describing potentials, problems, and challenges for health outcomes, concluding that capacity-building among elderly people and a specific model is beneficial for PPI [62]. Bergsten et al. shared a social and cultural perspective, describing how PPI in rheumatic diseases research planning sustained dignity, identity and quality of life for the researched group [65]. Bundgaard et al. highlight in a letter to the editor the need for debate of the utilization of PPI [71]. Siira et al. discussed the advantages and disadvantages of collecting information via online citizens and assess these panels potential in cardiovascular research [77]. Finally, Gilhus et al. discussed how PPI in Myastenia Gravis research could improve several aspects of research and clinical practice [74].

Theoretical frameworks used to characterize PPI

Theoretical underpinnings of PPI were reported in Table 4 and included 25 papers. Twelve papers reported using a framework originating in the UK [27, 28, 41, 42, 51, 54, 55, 58, 60, 61, 69, 79]. One study used NIHR framework to engage patients at different phases of the research process [51], while Staats et al. used it as a project design and management guideline [69]. Other frameworks reported specific objectives for PPI, including positioning theory as applied by Stuhlfauth et al. and Koren Solvang et al., which elaborates on how people use language to situate themselves and others [31, 32, 38]. One study reported to use a cooperative inquiry described by Heron and Reason [42].

Table 4 Theoretical frameworks used to describe PPI in healthcare research in the Nordic countries
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Research methods used to incorporate PPI and research stages

PPI was reported using diverse methods as visualized in Fig. 3. This included interviews [15, 24, 25, 27, 29, 36, 39, 41,42,43, 47, 52], focus groups [24, 27, 30,31,32, 34, 35, 40, 61, 65, 67], user panels or discussions [25, 38], workshops [29, 41, 48, 51, 54, 58, 60], written communications [15, 33, 49,50,51, 58, 59], surveys [53, 54, 58, 60, 61, 70] and steering groups or advisory boards [40, 44, 58, 62, 64].

Fig. 3
figure 3

Overview of methods applied on origin. Thirty-two studies reported one or more methods; thus the number of methods is not related to the number of studies. Different written data covers e.g. sticky notes, email correspondence and transcripts from meetings

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Fourteen studies reported details of recruitment and sampling strategies for PPI, and included purposive sampling [34, 35, 44, 49, 50], convenience sampling [25, 55, 70], snowball sampling in three studies conducted by the same author [31,32,33], maximum variation [26], stratified sampling [62] and all possible sampling [24].

PPI was utilized across various stages of the research cycle with 19 studies reporting PPI to identify and prioritize research questions [25, 28,29,30,31, 40, 42, 44, 45, 48, 51,52,53,54, 58, 60, 61, 65, 67], and 15 studies reported employing PPI during the commissioning stage [28, 34, 36, 38, 40, 45, 50,51,52, 54, 58, 65, 67, 68, 70]. In the designing & managing stage, PPI was used in 17 studies [15, 26, 29, 38, 40,41,42,43,44,45, 48,49,50,51,52, 61, 64] with patients providing feedback on the interview guide, methods, procedures, and study planning. Ten studies reported to involved patients actively in research [29, 34, 35, 38, 44, 45, 50,51,52, 58], with one study reporting involving patients and family in analysis [50], and another reporting asking patients to help organize qualitative themes [35]. PPI was reported used in the dissemination process in five studies [38, 44, 49,50,51], including collaboration with patients on optimal methods for communication of research and including patients on advisory boards, in posters, presentations and publications [49, 50]. Two studies reported to use PPI in research implementation [51, 52], and six studies utilized PPI in research evaluation through interviews [29, 46], consultation on wording and expression [51], validating the study design [44, 45] and cancellation of a planned randomized controlled trial [30].

Impact of PPI in research

Six papers reported and evaluated how PPI impacted the utilization of their research [29, 30, 44,45,46, 51]. The impact of PPI in the research differed in methods used for measuring impact and the specific study findings depending on the different approach to involve PPI. For example, Handberg et al. cancelled an RCT as PPI confirmed the irrelevance of the RCT [30]. Madsen et al. reported the enhancement and validation of their study by using PPI [44]. However, the specific impact of PPI was not outlined. Schandl et al. used GRIPP2 to report the use of PPI and found that PPI improved the relevance and facilitated the dissemination [45]. Nissen et al. concluded that PPI may contribute to enhancing the relevancy and quality of the research [15].

Through our gray literature search, we identified policies, practices, and initiatives of PPI in the Nordic countries from a range of sources, including government, academic institutions, funding bodies, patient organizations, and regional authorities to uncover the dissemination of PPI across different sectors. The evident diversity among these sources reflects the variations that exist across countries, institutions, and organizations within the Nordic region.

Discussion

With the aim of exploring the current state, practice, and impact of PPI in healthcare research in the Nordic countries, our main finding was the intensified use of PPI in healthcare research in the selected geographic area. This was evidenced by an increasing number of publications and institutional initiatives in the recent years to involve patients and public in healthcare research. The most widely utilized theoretical frameworks were JLA and NIHR, both developed in the United Kingdom. This is not surprising, given the cultural and geographic proximity of the United Kingdom and the Nordic countries [80].

Although a universal definition of PPI might be lacking, we identified some studies in our scoping review that reported specific PPI aims in their research [27, 51]. A systematic review of cancer research in Europe found that PPI was mainly used in the first stages of research [8], which could be a sign of early days in the integration of PPI in the research process. This highlights the need for further exploration and development of PPI practices to ensure its full integration and meaningful impact on the research process.

Overall, this scoping review showed that PPI methods and approaches in Nordic literature is comparable to other international references [5, 8]. This suggests that the Nordic countries are aligning with global trends and recognizing the significance of involving patients and the public in healthcare research. In our scoping review, we found differences within the Nordic countries as Denmark, Norway, and Sweden contributed more references than Finland and Iceland. This can be explained by our language barriers and thus exclusion of documents in Finnish or Icelandic. Furthermore, Iceland has a smaller population size and may therefore contribute with fewer references. These findings are supported in a recent review focusing on PPI in Europe concluding that Scandinavian countries (Denmark, Norway, and Sweden) use PPI to a greater extent than Finland and Iceland [5].

The integration method of PPI in the research process exhibited variations across studies. We identified 14 empirical studies reporting the sampling strategy used in relation to PPI and found that the choice of strategy varied across studies. The absence of a sampling strategy could potentially lead to misrepresentation of involvement in the research process and affect the impact of PPI in relation to the study results [81]. Frögren et al. showed an over representation of people with higher education who were more willing to be involved in PPI [56]. This may pose a risk that groups with lower levels of education may not have been represented in PPI activities, potentially resulting in a biased representation. In our scoping review, we found a general absence in the level of detail provided regarding the comprehensiveness,scope, and timeliness of patients´experiences. Specifically, there is limited information about when these experiences occurred and the time since undergoing treatment. This could potentially impact the results of our study. Therefore, this review highlights the need for more detailed descriptions of PPI participants in future research to detect and address potential biases. To mitigate this risk, it is essential to actively strive for diversity and inclusivity in PPI initiatives. It is crucial to ensure that PPI strives for equal representation and prevent exclusion of those with limited resources to mitigate social inequality. The included papers in this scoping review did not prioritize sociodemographic descriptions of PPI participants. The references found in this review primarily involved patients or a combination of patients and the public. Only six studies solely involved the public. It may be relevant to investigate (in future studies) the distinctions between involving people with direct knowledge and experience of disease and treatment versus involving the broader public who have vested interest in ensuring the provision of high quality care.

In this review, interviews emerged as the preferred method for integrating PPI. However, the wide variety of qualitative and quantitative methods used in European studies involving different populations suggest that there is either a range of suitable research methods available or a potential lack of systematic approaches for PPI integration in the research process [8].

The most frequent type of reference identified in this review was empirical studies. In these studies, a discussion of aim and impact of PPI was rarely touched upon, perhaps due to word constraints in scientific  journals. As such, we still need more knowledge regarding the impact of PPI in healthcare research in the Nordic countries [5, 8, 9].

The references in our review did not sufficiently uncover the positive or negative impact of PPI in healthcare research. Empirical studies reported very little description of PPI, whereas non-empirical papers were more apt to have a critical eye on PPI. Non-empirical papers presented a broader perspective and offered a discussion of how to measure the impact of PPI in research. Some studies in our review described how PPI enhanced and validated their study and even a cancellation of a RCT [30]. In these cases, PPI had a favorable influence, albeit with varied outcomes. It is important to acknowledge that conducing an unnecessary RCT constitutes misallocation of funding and resources.

Staniszewska et al. discussed the negative impact of PPI in earlier papers and how formalization of more recent publications has become a barrier to critical discussion of the concept [82]. Russel et al. also argued that more research regarding the negative effects of PPI in healthcare research was necessary, as PPI may increase inequality rather that amplifying specific voices and agendas, and calls for a discussion of how to distinguish among measuring, impact, and evaluation [9]. Malterud and Elvbakken expressed their hesitations regarding the intensified use of PPI in healthcare research [83]. Their concerns were that PPI is prioritized at the expense of academic skills, scientific quality, and knowledge outcomes, which may be because of the nature of the papers. Pii et al. also noted a lack of critical reflection on the PPI process, with challenges being only briefly described [8]. Furthermore, Pii et al. stated that some papers reported the use of PPI in the healthcare research as time-consuming. This challenge was supported by Bombard et al. who argued that PPI could be perceived as too time-consuming, burdensome, tokenistic, and disappointing, especially if suggestions were not adopted [84]. Open and constructive discussions to address potential challenges and limitations of PPI in research continues to be warranted.

In our scoping review, we identified gray literature from all five Nordic countries, however more gray literature sources were found from Denmark than other Nordic countries. This discrepancy can be attributed to our research team being based in Denmark. PPI was predominately given consideration at universities and funding bodies. Despite the increasing interest in PPI, we found no obvious collaboration among organizational and institutional stakeholders. Sand et al. described the importance of exchanging views and experiences regarding PPI to enhance its relevance and quality of utilization [2].

The quality of PPI in healthcare research could potentially be improved by establishing national and Nordic consensus for conducting and reporting PPI as they provide guidance and support to researchers enabling to standardized approach to PPI implementation. The UK based NIHR offers an advanced guideline on PPI utilization in healthcare research, and even a detailed calculator of expenses when incorporating PPI [85]. Due to the lack of consensus in the Nordic countries, the integration of PPI is more challenging, despite a generally positive interest and minimal resistance. A recent study from Denmark presented guidelines for researchers discussing methods for integrating PPI [79]. The authors highlighted that a systematic approach to monitoring the extent and impact of PPI is warranted, as a common guideline may improve PPI quality through transparency, consistency and effectiveness in planning, execution and reporting activities.

Despite the growing interest in including PPI in healthcare research, our findings indicate that the impact and meaningful evidence of PPI are still underreported. A European handbook of meaningful patient involvement was published in 2003, and a Canadian instrument was developed to measure meaningful patient and user engagement [86, 87]. A similar instrument has not been developed for the Nordic countries. We found the modified GRIPP2-SF to be valuable for extracting PPI information from the specific research studies due to its comprehensive and user-friendly nature. However, adapting the extraction of PPI information to the Nordic context could convey other aspects beyond the scope of this review. Given the healthcare systems being funded through taxation in the Nordic countries, people involved in research may have different motivations for their participation and contributions to healthcare, e.g., patients might perceive their involvement as a means of contributing back to both the healthcare system and the broader society. Extracting the impact of PPI from the empirical studies in our review was challenging, and as a result, our knowledge of the positive and negative impact of PPI in the Nordic countries remains limited.

Strengths and limitations

This scoping review is the first to explore and delineate the current state, practice, and impact of PPI in healthcare research across various healthcare domains and patient populations within the Nordic countries. Our comprehensive systematic and gray literature search, which included nine databases with a wide range of search terms, enabled retrieval of a considerable number of references and provided a unique and synergistic review of PPI in the Nordic countries. Using GRIPP2-SF, the included empirical studies were assessed, providing a comprehensive overview of the intent, utilization, and impact of PPI in the Nordic countries. Overall, access to the experiences of PPI in healthcare research was readily available, giving us the added advantage of learning from other Nordic countries. Additionally, empirical papers did not generally describe the specific aims, outcomes, and impact of PPI.

Due to the wide range of PPI terms and the broad scope of our investigation, the search yielded a large number of references with high search sensitivity but low specificity, indicating that while the search retrieved articles of interest, it also included a significant number of articles that were not pertinent to our review.

There were limitations in accessing gray literature from Finland and Iceland, despite our attempts to involve researchers from these two countries, who declined due to limited resources, interest, and funding. The study was skewed due to the investigators’ familiarity with Danish, Norwegian and Swedish language and sparce knowledge of Finnish and Icelandic.

Implications

The recommendations and future research presented in this scoping review are derived from our findings which aimed to investigate PPI in healthcare research and its impact in the Nordic countries. However, this review posed challenges due to the lack of explicit PPI strategies in healthcare research within these countries. To address this issue, we suggest that each country articulate its approach or policy on PPI in research. This might promote and facilitate a more effective use of PPI to improve overall research outcomes. Collaboration among organizations and institutions, coupled with improved communication, could facilitate a more extensive exchange of experiences and knowledge. This could contribute to the development and assessments of PPI approaches, which are crucial in improving the evaluation of PPI’s impact. PPI could contribute to the improvement of research quality and enhance the relevance and impact of healthcare research, such as improved recruitment and dropout rates [88]. Standardization of PPI approaches could potentially enhance impact within the specific study context and improve methods for measurement of impact and comparison of PPI utilization. However, merely fulfilling PPI requirements mandated by funding bodies may not improve research quality. We suggest, that actively involving patients and the public may result in researchers ensuring that their studies address the needs and priorities of the target population, leading to more impactful and patient-centered research outcomes. Further, enhancing the precision and transparency in describing the recruitment and sampling strategy of people involved could be beneficial. For instance, considering patients’ level of involvement in the research process based on where they are within their treatment trajectory, such as whether they are at the beginning or end of their treatment. PPI highlights the potential for cross-cultural learning and the exchange of best practices in PPI between Nordic countries and the international research community. Future healthcare researchers could benefit from education and guidance on effectively integrating PPI into their research, which could involve learning about various PPI methods and theoretical frameworks, and evaluating the impact of PPI in the context of healthcare research.

Conclusions

In this scoping review, we examined the trends and practices of PPI in healthcare research across the Nordic countries. We observed a substantial growth in the number of references reporting and addressing PPI in healthcare research, indicating a growing interest in the topic within the Nordic countries. Despite similarities in healthcare systems, there were variations in PPI methodologies, demonstrating its broad application. Despite these variations, there is a shared emphasis on person-centered research practices within the Nordic countries. Given that PPI is a relatively new research approach in the Nordic countries, specific implications have not yet fully emerged. The diverse application of PPI methods and frameworks suggests a lack of established national and international recommendations. This diversity, while enriching the field, also poses challenges in interpreting and synthesizing the findings of our scoping review. Further, it is advisable to consider cost–benefit analyses to rationalize the impact of PPI, so researchers can ensure that PPI efforts are meaningful, efficient, and sustainable, thereby optimizing the positive outcomes while minimizing unnecessary costs.