This scoping review protocol is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) checklist (see Additional file 1).

Search strategy

The search strategy comprises three main stages (see Fig. 2). The first stage involved searching the newly created Health CASCADE Co-creation Database. This database was created by members of the Health CASCADE network and was aimed at collecting in one place the entire corpus of literature pertaining to participatory research and co-creation (1). This database was created using CINAHL, PubMed and all databases accessible via ProQuest through Glasgow Caledonian University (GCU) institutional licence (17 databases in total, APA PsycArticles®, APA PsycInfo®, Art, Design & Architecture Collection, British Periodicals, Coronavirus Research Database, Early Modern Books, Ebook Central, Entertainment Industry Magazine Archive, Humanities Index, Periodicals Archive Online, ProQuest One AcademicTrial-Limited time only, PTSDpubs, SciTech Premium Collection, Social Science Premium Collection, Sports Medicine & Education Index, The Vogue Archive, and The Women's Wear Daily Archive). The key search terms used in this search strategy are found in Table 1. ASReview, an artificial intelligence (AI) aided platform that helps find relevant records was used for screening the records to be included in this database. The AI performs a textual analysis of the provided records, based on active learning and prioritization. Given the large volume of records retrieved from PubMed, CINAHL, and all databases available through ProQuest with GCU access, AI was necessary to speed up the screening process. There are over 13,000 records contained in this database, with all titles and abstracts containing at least one of the search terms.

Fig. 2

Stages of search strategy

Table 1 Key search terms used to capture co-creation

The Health CASCADE Co-creation Database was searched using free-text terms relating to co-creation experience (see Table 2). Search terms have been developed in reference to the research question and through consultation with members of the Health CASCADE consortium. The search will be piloted to check the appropriateness of keywords and to ensure known studies are identified.

Table 2 Search terms used to capture the co-creation experience

The second stage of the search strategy is to use both sets of search terms (see Tables 1 and 2) in Scopus using the Boolean operator AND to combine the two sets. This is to provide additional robustness to the search. Due to the large volume of records retrieved (> 35,000) when combining the two sets of search terms, it is necessary to omit some search terms used to create the Health CASCADE Co-creation Database. Four search terms will be retained “co-creat*”, “co-production”, “co-design” and “experience-based design”. These search terms are specifically chosen because co-production and co-design are commonly used interchangeably with the term co-creation [21]. In addition, “experience-based design” is retained due to the obvious focus on the experience. We will include articles that meet our inclusion criteria for co-creation, regardless of the terminology used to describe the methodology. For pragmatic reasons, sources of unpublished empirical studies (including grey literature, theses, and dissertations) will not be searched for. The draft search strategy for Scopus is available in Additional file 2.

The final stage of the search is to employ snowballing to capture any additional articles that may be potentially missed. An artificial intelligence tool called Connected Papers [22] will be used to identify papers that (1) the included paper has cited (backward reference searching), and (2) papers that have since cited the included paper (forward reference searching).

The article selection process is considered an iterative process, whereby the search strategy will be initially broad and then refined based on abstracts retrieved and as reviewer familiarity with the literature increases. The concept of co-creation is defined differently depending on the setting and context and is often used interchangeably with similar, yet distinct concepts, but equally lacking a clear universal understanding [21]. Therefore, to account for the overlaps in terminology a broad scope will be initially implemented.

As recommended by Arksey and O’Malley [23], decisions on how to set search parameters will be made after a general scope of the field has been gained. Hence, this stage will require the reviewer(s) to engage in a reflexive way and repeat steps to ensure a comprehensive literature search with more sensitive searches [23, 24].

Inclusion/exclusion criteria

All study participants in the included papers must be adults, described as people aged 18 years and over with no upper limit. Children/adolescents are not included in this study as research indicates that there are differences between their emotional experiences in terms of emotional intensity and stability [25].

Empirical articles (i.e. primary research studies) include any qualitative, quantitative, and mixed-method research designs that include a description of the co-created product, service, or intervention and an evaluation of the co-creators’ co-creation experience. Although scoping reviews can draw on evidence from non-empirical sources, this review imposes limits to include empirical sources only as empirical sources would be most useful and appropriate for contributing to an evidence-based understanding of co-creation methods.

Any context that involves the co-creation of a product, service, or intervention will be considered.

The Health CASCADE Co-creation Database is limited to searching records between 1st January 1970 and 1st December 2021. The search in Scopus will include records from 1st January 1970 until the date of the search.

The Health CASCADE Co-creation Database is limited to only include materials that are written in English. However, for the search conducted in Scopus, publications in English, Spanish, Dutch, French, and Chinese languages will also be considered, as the research team has proficient fluency in these languages.

Data extraction

Following the database search, articles will be exported as a CSV file for removal of duplicates in Excel. The articles will be imported and screened in Rayyan. The title and abstract of all studies will be screened independently by several reviewers (LMcC, QA, QL, EW, GRL, RC, and MV) and irrelevant studies will be removed. All titles and abstracts will be double-screened. Full-text articles of studies identified as potentially relevant for inclusion will subsequently be sought and screened by several reviewers (LMcC, QA, QL, EW, GRL, RC, MV, and KM) against the agreed set of criteria. Differences of opinion regarding inclusion or exclusion will be resolved by discussion and reaching a consensus or by a third reviewer. The results of the search and the study inclusion process will be reported in full in the final scoping review and presented both narratively and by use of the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review (PRISMA-ScR) flow diagram.

To determine the extent of research on co-creation experience (objective 1), details about co-creation more generally will first be extracted. This includes:

Study’s definition of co-creation and co-creation experience (if available).

The context or setting.

Data about the participants (number, type, and characteristics of co-creators’ involved).

Description of the co-creation process undertaken (including number of sessions, level of participation).

Purpose of co-creation.

Outcome of the co-created intervention, service, or product.

The key characteristics of psychological and emotional experience including positive and negative components (objective 2) will be extracted.

The psychological theory underpinning the co-creation experience identified by the authors of the studies (objective 3) will be recorded.

Information about the technology or tools that had an impact on the co-creation experience (objective 4) will be extracted.

Additional descriptive information such as discipline and date of publication will also be extracted.

The above-extracted information will be entered into an Excel spreadsheet developed by the authors. This data extraction Excel spreadsheet may be modified and revised as necessary during the process of extracting data from the included evidence sources to ensure that key findings relevant to the review question are addressed.

Quality assessment

There exists debate as to whether a scoping review should contain an assessment of study quality [26]. A quality assessment component will be included in this review in relation to the sufficiency of reporting the process of co-creating an intervention, service, or product. This tool (see Table 3) has been adapted from Leask et al.’s [4] ‘checklist for reporting intervention co-creation’ and Eyles et al.’s [27] amended version of a checklist for reporting non-pharmacological interventions. The reason for including this checklist is two-fold. Firstly, the scoping review may contain a variety of study designs and the focus is not solely on the outcomes, but rather on the process [27]. Secondly, as explained above, the concept of co-creation is used interchangeably with other similar overlapping concepts, such that some processes may be described as co-creation when they are in fact not (according to the definition used in this review) or vice versa. Therefore, by incorporating this checklist, it will become clearer as to the type or extent of co-creation processes that were implemented and whether they were clearly reported within each individual source of empirical evidence. However, given that a scoping review aims to present an overview of the extant literature on a particular topic without synthesis from individual studies, no study will be excluded on the basis of the quality of reporting co-created interventions.

Table 3 Checklist for sufficiently reporting co-created intervention, service, or productStrategy for data analysis

The PRISMA-ScR will be used to guide the reporting of the scoping review [28]. Whilst, the synthesis of the results from included sources of evidence is more appropriately done with a systematic review, the analysis of data in scoping reviews is generally descriptive in nature [29]. A narrative summary of extracted data will be produced along with the tabulated and/or charted results described in relation to the review question and objectives. Descriptive techniques, such as basic coding of data to particular categories, are recommended as a useful approach when the purpose is to identify concepts or key characteristics related to the concept [20]. Data will be analysed using the well-established method of thematic analysis [30]. This method is characterised by identifying and reporting recurring themes within the data and is a suitable analytic method because it allows for patterns of experience to be recorded, such as understanding adults’ experiences of participating in co-creation. We intend to extract relevant co-creation experience data from the result sections of articles, including verbatim participant quotations. For quantitative data, such as questionnaires, we will attempt to extract the item statements and code them alongside the qualitative data.