This is a protocol for a scoping review to answer broad research questions based on defined selection criteria [20]. We used the guidelines of the Joanna Briggs Institute Reviewer’s Manual [20], based on the theoretical framework proposed by Arkey and O’Malley [21], updated by Levac et al [22], and guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) [23].

The stages of the scoping review include (1) definition and alignment of research objectives and questions; (2) development and alignment of inclusion criteria; (3) description of the search for evidence, selection and extraction of data, and presentation of evidence; (4) the search for evidence; (5) selection of evidence; (6) extraction of evidence; (7) analysis of evidence; (8) presentation of the results; and (9) a summary of the evidence, conclusions, and the implications of the findings [20].

The mnemonic PCC (population, concept, context) underlay formulation of the research question. This model allows broadly mapping information to identify knowledge gaps, present key concepts, quantify aspects of interest, and expose practices and evidence of a particular theme [20]. We defined the population as people diagnosed with syphilis, the concept as spatial analysis, and the context as health care. Thus, the research question is “How has spatial analysis been used in syphilis-related research in health care?”

Studies will be included if the full text is available, they address syphilis, and they use any geographic information systems software and spatial analysis technique. Studies will be included independently of sample characteristics and size. Studies published as research articles, theses, dissertations, and government documents will be considered with no location, time, or language restrictions. An external translator will be used when needed.

Studies will be excluded if they are literature reviews, debates, documents, editorials, expert opinions, comments, opinion articles, or conference or poster abstracts. Studies that do not have syphilis as the primary outcome, have an insufficient methodological description, or do not answer the research question will also be excluded.

The search strategy will be conducted in 3 steps to reach the largest number of publications possible.

The search strategy will be adapted to each database. The free version of Rayyan (Qatar Foundation) [26] will be used for duplicate removal and study selection. Two reviewers (JdCD and YTP) will conduct a pilot test to reduce biases, standardize the selection process, and verify agreement with the study protocol. Each author will select 25 studies and read the titles and abstracts; the screening will follow the eligibility criteria. The team will then discuss any discrepancies and make necessary changes to the criteria and definitions. The screening will start only after 75% agreement is reached [20].

After the pilot test, 2 blind reviewers (JdCD and YTP) will use Rayyan [26] to read the titles and abstracts of all identified studies, evaluating them according to the inclusion criteria. In cases of disagreement, a third reviewer (RARdS) will be consulted.

After reading the full text, potentially eligible publications will be retrieved in full via their titles and abstracts and exported to a Microsoft Excel database (2020 version; Microsoft Corp). Full texts will be analyzed and reasons for exclusion will be recorded. Information regarding the selection of publications, eligibility criteria, and reasons for inclusion and exclusion will be reported in the PRISMA-ScR flowchart [27].

Data will be extracted using a spreadsheet built in Microsoft Excel (Table 2). Two trained reviewers (JdCD and YTP) will extract the data.

Two reviewers will map the application of spatial analysis in syphilis-related research using geographic data and by identifying where the study was performed. The map will be developed using a Google spreadsheet.

Results will be interpreted qualitatively and quantitatively and presented using a PRISMA-ScR flowchart [27]. SPSS (version 24.0; IBM Corp) will be used for statistical analysis. The quantitative analysis will use descriptive statistics with the absolute frequency and percentage. Thematic analysis will be used in the qualitative analysis due to its flexibility in identifying patterns in research questions [28,29]. A thematic analysis will categorize the application of spatial analysis in syphilis-related research in health care. The results will be discussed using the literature and research objectives and questions.

The final report guided by PRISMA-ScR will include the results in flowcharts, graphs, or figures [23]. We will use images to help readers understand the results of the studies. As the theme of the presented protocol involves spatial analysis, it is very likely that some of the results will be shown in map images.

After carrying out the previous steps, we will prepare a summary of the results of the scoping review linked to the objective of the study. This way, the conclusion of the study will be grounded and presented effectively. We will highlight knowledge gaps that may arise in the development of the scoping review to provide direction for future studies.

This protocol will guide a scoping review to identify and map the use of spatial analysis as a tool in syphilis-related research in health care. Spatial analysis in health care research can identify the spatial distribution of high-incidence diseases, identify associations in their distribution with determining factors, and support direct health planning and actions [31-33].

The United Nations proposed the elimination of congenital syphilis by 2030, reducing its incidence to 0.5 cases per 1000 live births [34]. Strategies to prevent syphilis are a concern of authorities worldwide and are included in the sustainable development goals. Therefore, this review will help develop specific health strategies to control syphilis.

The research team involved in this protocol has experience studying syphilis and spatial analysis and has knowledge and experience in scoping reviews. A librarian helped develop the high-sensitivity search strategy, which is based on a combination of 4 vocabularies and will expand the results and allow access to the literature; an especially important point is the lack of time and language restrictions.

A test search with terms for epidemiology, treatment, prevalence, and incidence was performed in the thematic context group (on the use of spatial analysis in health care). However, the search had restricted results and directed the research question to a certain type of technique, creating bias. Thus, we left the “context” field empty and searched for all possibilities for using spatial analysis in health care.

The study limitations will include the lack of a search for institutional sites in all countries (ie, for gray literature at these sites), but this should not affect study development. We will select essential databases to minimize this limitation. The use of descriptors and search terms in only English and Portuguese may be another limitation of the study.

This study protocol presents the main methodological steps that will guide the proposed scoping review and identify and map studies that use spatial analysis as a tool in syphilis-related research in health care. The review may reveal areas with the highest incidence of syphilis, identify which countries most use spatial analysis to study syphilis, and determine the applicability of the technique for syphilis research in each continent.

The results will be published in open access and peer-reviewed journals, favoring the dissemination of knowledge in the scientific community.