A pragmatic approach to this systematic review [33] will be undertaken. The overall research question seeks to simplify a complex interaction of diverse populations, systems, and variables that operate in the prehospital cardiac care space. Within this context, the review seeks to determine the service and system-level variables that affect a patients’ journey along the care pathway. For the purposes of this review, the working definition of OHCE will be broad and includes (but is not limited to) cardiac arrest, myocardial infarction, arrhythmia, and chest pain.

This systematic review aims to answer the question:

The systematic review also aims to:

The search strategy, developed in consultation with a specialist librarian, will use a number of medical literature databases and search engines to identify literature for review. The sources include:

Different combinations of Medical Subject Headings (MeSH) terms and keywords related to ethnicity and race, equity, and CVD will be used. During the initial scoping for this review, a very limited number of articles related to the out-of-hospital care pathway in New Zealand were identified. The research question and therefore the search terms for the population of interest were broadened to include other minoritized ethnic communities globally. Although the scope of the review was expanded, the review will be underpinned by Kaupapa Māori research, which seeks to validate Māori experiences in the context of a colonized society [34]. Therefore, the MeSH terms for Māori and Pacific Islander peoples were added as specific search terms in recognition of this. The MeSH terms for Indigenous peoples have been included to capture research specific to other Indigenous or First Nations populations.

As relevant articles are identified, the reference lists will be checked for additional studies and reviews. The search will include articles relating to original research that are published in English with no exclusions due to research design or country setting. The date of publication will be limited to between January 1, 2000, and January 1, 2023. Textbox 1 outlines the search terms that will be used.

Textbox 2 outlines the inclusion and exclusion criteria that will be used.

All peer-reviewed, original research studies will be considered for inclusion. The “community” setting will include all settings in the prehospital phase, up to arrival at a hospital or emergency medical center. There will be no restriction by country.

The population is broadly defined as all adults, aged 18 years and older, from minoritized ethnic communities who experience an acute, nontraumatic cardiac event outside of a hospital. The term “minoritized” is purposely chosen to reflect communities whose “collective cultural, economic, political, and social power has been eroded” [35]. The reference group is nonminoritized ethnic populations.

All types of acute cardiac events with a nontraumatic etiology will be considered, including but not limited to cardiac arrest, chest pain, arrhythmia, and myocardial infarction.

Any type of outcome measures will be included where ethnic and racial specific comparisons within a country are conducted. Analyses may include stratified analyses, the investigation of interactions or effect modification, and comparisons using qualitative data. Outcome measures from multicountry studies will be included if the ethnic groups analyzed are comparable. The primary outcomes will include the analysis of any factors that affect the pathways of care (time, journey, and the process taken to care) and barriers and enablers to prehospital care. This will include outcomes related to comorbidities, health education, symptom recognition, patient and EMS decision-making, care-seeking processes, access to CPR and automated external defibrillator, or informal care received before EMS contact. The secondary outcomes will be any gender analysis by ethnicity and race.

The first author will undertake the literature search. Identified studies will be collated and managed in an EndNote library created for this review once the studies have been imported to the library. Duplicate entries will be removed before stage 1 of the critical appraisal process. During the initial review process, 2 authors will screen the title and abstract of each article to ensure that papers meet the inclusion criteria.

At stage 2 of the critical appraisal, the full text will be obtained for all articles, and every study will be evaluated by at least 2 authors using the Mixed Methods Appraisal Tool (MMAT) [36]. The MMAT provides a standardized table of quality assessment criteria that can be used for qualitative and quantitative research designs. All studies with Indigenous populations will also be reviewed using the CONSIDER (Consolidated Criteria for Strengthening the Reporting of Health Research Involving Indigenous Peoples) statement [37]. The CONSIDER statement provides a checklist that serves to strengthen Indigenous health outcomes by improving research practice and reporting. Study authors will be contacted to clarify results, resolve any uncertainties, and obtain additional information if needed. Risk of bias will be undertaken using the Graphic Appraisal Tool for Epidemiological studies. Assessment will be done at both study and outcome levels. Articles for inclusion will be identified by all review authors. The included reference lists for included articles will be scanned to identify further articles that may be eligible for inclusion. Articles identified at this stage will also be appraised using the MMAT and CONSIDER statement where appropriate. During the critical appraisal, any disagreement about the inclusion or exclusion of a paper will be resolved by discussion with all review authors.

Data for extraction will include general study information, study characteristics, participant characteristics, and study results measured on outcomes identified in this protocol. Appraisals and data extraction will be independently extracted by the authors and recorded in a form. A standardized data extraction form will be used, which will be piloted and refined to ensure that there is consistency between the multiple reviewers. Once finalized, the completed form will populate a Microsoft Excel spreadsheet that will be used for data analysis.

Each eligible study will have data extracted under 4 domains (Textbox 3).

The synthesis of the data will be underpinned by an Indigenous data sovereignty approach that requires researchers to critique how data about Indigenous peoples are collected, used, and analyzed [38,39]. A convergent integrated approach to the data synthesis [40] will be undertaken, whereby quantitative findings will be “qualitized” before conversion to narratives.

It is unlikely that this review will obtain sufficient data that are similar enough to conduct a meta-analysis. It is therefore expected that the authors will conduct a narrative synthesis of the data.

The review findings will be reported according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [41]. The PRISMA 2020 flow diagram will be used to guide the recording of the number of articles identified, screened, included, and excluded.

This is a protocol for a systematic review; therefore, no patients or public will be involved. However, the proposal and approach were informed by discussion with service providers in the prehospital sector in New Zealand. Patient consent for publication is not required.

Ethics approval is not required for this systematic review as it is reviewing already anonymized, published data.

This paper presents a methodological description of a systematic review process that seeks to inform equity-based intervention and practice. CVD is the leading cause of mortality and morbidity globally. The rates of CVD-related morbidity and mortality have increased, particularly in low- to middle-income countries, [42]. Although population aging contributes to increasing CVD rates globally, barriers to accessing care widens the gap between countries [43] and within countries. For Indigenous and other minoritized ethnic peoples experiencing inequities, identifying the barriers to accessing care is vital for creating culturally grounded interventions that reduce the health inequities they experience [44,45]. This review will contribute to the existing body of knowledge by identifying the factors that improve access to care for different ethnic groups following an OHCE. By integrating an Indigenous quality appraisal tool and research methodology, the review will provide evidence with a uniquely positioned equity lens. It is intended that this will provide insight into areas where interventions can be targeted to increase access to care for ethnic groups in New Zealand and globally. The resulting systematic review will present an unbiased and detailed summary of the current evidence available about the experiences of minoritized populations accessing care following an OHCE compared with nonminoritized populations. The results of this review will inform researchers and emergency service providers on variables related to equity-centered service provision and intervention in the community setting.

The strengths of the resulting systematic review include the following:

The limitations of the resulting systematic review include the following:

This systematic review protocol illustrates the transparency of the research and provides a process for conducting a similar review.