Our review will be based on the Arksey and O’Malley methodological framework for scoping reviews, which includes the following six steps: (1) identifying the research question; (2) identifying the relevant studies; (3) defining the study selection criteria; (4) charting the data; (5) collating, summarizing, and reporting the results; and (6) optionally consulting with peers for additional feedback and the validation of findings [24].

Our approach will result in the wide coverage of the literature. The decision to narrow down the literature will be made once the reviewers have a sense of the volume and general scope of the literature and gain familiarity with the literature and the field, after conducting the search [24]. The tools recommended by Levac et al [25] and the Joanna Briggs Institute [26-28], which are grounded on Arksey and O’Malley’s [24] earlier work, will be leveraged to conduct and report our scoping review in a structured way. These tools include the Population, Concept, and Context (PCC) framework and the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines and checklist.

Our scoping review aims to address the following research questions:

The PCC framework was utilized to identify the main concepts of the research questions (Table 1). Initial iterative searches in MEDLINE were conducted by the principal investigator (AL) to identify relevant articles and subject headings.

Further iterative searches against MEDLINE were conducted in collaboration with a professional information specialist, resulting in a more refined search strategy that produced 4972 results (Multimedia Appendix 1). This search strategy was then submitted to a second information specialist for a peer review assessment and the validation of the quality and comprehensiveness of the search strategy, in accordance with the PRESS (Peer Review of Electronic Search Strategies) 2015 guideline [29]. Comments were reviewed, and adjustments were made to the strategy as deemed appropriate.

The intervention of interest is secure messaging use in the treatment of diabetes within primary care settings. The care settings will comprise noninstitutionalized and nonhospital settings. This aligns with the definitions of primary care by the World Health Organization [30] and Health Canada, whereby primary care is considered an “element within primary health care that focusses on health care services, including health promotion, illness and injury prevention, and the diagnosis and treatment of illness and injury” [31].

Our strategy utilizes a combination of controlled vocabulary (eg, Diabetes Mellitus, Telemedicine, and Patient Portals) and free-text terms (eg, NIDDM, virtual consult, and secure email). Using the Ovid platform, we will search Ovid MEDLINE ALL, Embase, and APA PsycINFO. We will also search the Cochrane Library on Wiley, CINAHL on EBSCO, and PubMed. Vocabulary and syntax will be adjusted across the databases. No language or date limits will be applied, but animal-only records will be removed where possible. Results will be downloaded and deduplicated by using EndNote 9.3.3 (Clarivate Plc) and uploaded to Covidence (Veritas Health Innovation Ltd).

The reference lists of all included studies will also be hand searched to identify additional literature that may not be captured through the database search. Additional grey literature will also be identified through an existing network of reviewers, relevant journals, organizations, conferences, and a community of practices across the globe. EndNote software will be utilized to manage references.

Based on the research questions and objectives, the inclusion and exclusion criteria shown in Table 2 will be used to initially guide the review. The further refinement of these criteria will occur in an iterative manner as the reviewers gain a better understanding of the scope of available literature. In alignment with the PCC framework, the initial inclusion criteria will include those for the population (patients with diabetes), concept (secure messages), and context (primary and community care settings). The use of secure messaging for patient-provider, caregiver-provider, and provider-provider communications will be included. The initial exclusion criteria will be patients with gestational diabetes, other virtual or digital health interventions, and institutionalized or hospital settings.

The review team consists of the following three reviewers: the principal investigator (AL), the supervisor (DM), and the cosupervisor (TS). Due to its convenience, Covidence will be used by the reviewers to independently screen the articles, based on the inclusion and exclusion criteria, in the following two steps: (1) title and abstract review and (2) full-text review of the full-text articles and documents. To be more inclusive and reduce the risk of excluding relevant studies, any articles that reviewers are unsure of during the title and abstract scan will be moved forward to the full-text review stage.

Data extraction will be conducted outside of Covidence, using a charting form (Multimedia Appendix 2) that we initially created based on Arksey and O’Malley’s [24] recommendations, which include the following elements: author(s), year of publication, study location, intervention type, comparator (if any), duration of the intervention, study populations, aims of the study, methodology, outcome measures, and important results.

Two reviewers will pilot the data extraction form on the first 30 articles to identify the need for modification. The review team will further revise the form, as needed, during the data extraction process as new relevant data types and themes are encountered.

The review team will utilize the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) chart and PRISMA-ScR checklist [27] to report their findings in a clear, transparent way (Multimedia Appendix 3 [28] and Multimedia Appendix 4 [27]).

A narrative summary of findings will be developed based on the elements of the data extraction form and guided by the context of the research question and study objectives. Throughout the course of the review, if other criteria or elements are uncovered, the authors will decide on other additional formats (eg, graphs, tables, and diagrams) for presenting the study findings.

At different stages, experts will be consulted to review and provide feedback. In stage 2, prior to executing the final search, the search strategy will undergo a peer review by a qualified librarian to ensure relevance and achieve more holistic search results. Other experts within the field will also be drawn from our networks to ensure that relevant findings are captured and reported in a clear manner. In stages 3 to 5, experts will also be consulted to suggest additional literature and provide feedback on the data extraction form.

The experts we consult will include researchers and practitioners within the digital health field and decision makers from publicly funded payer organizations.

Neither ethics approval nor participant consent is required, as our scoping review will not include human or animal participants. Data will be collected from published literature.

Our scoping review will explore what is known about the use of secure messaging in the treatment of diabetes within the primary care setting. The review will contribute to knowledge on this topic by examining how the impact of secure messaging has been assessed from the patient, health system, and quality of care perspectives. To our knowledge, this has not been the focus of previous reviews [11,15,22,23].

The findings of the scoping review will inform health care policy makers’ decisions on virtual care services.

Our scoping review will use an established framework and a comprehensive systematic search to identify and review existing literature on the use of secure messaging in the treatment of diabetes to date. The search strategy is peer-reviewed, and the grey literature search and the review will be informed and guided via consultation with experts. Although the findings will be useful in understanding the state of the literature and potential research gaps, the study does not aim to conduct a full assessment of the quality of the evidence in the literature uncovered.