Guide for authors

Revista Clínica Española published its first issue in 1940 and is the communication channel of the Spanish Society of Internal Medicine (SEMI).

Revista Clínica Española fully endorses the goals of updating knowledge and facilitating the understanding of key developments in internal medicine applied to clinical practice.

Revista Clínica Española is subject to a thorough double-blind review of the received articles written in Spanish or English. Nine issues are published each year, including mostly originals, reviews and consensus documents.

Revista Clínica Española is included, amongst other databases, in: Current Contents/Clinical Medicine, JCR/SCI-Expanded, Index Medicus/Medline and Excerpta Medica/EMBASE.

Articles by Spanish authors should comply with the general criteria of Law 14/2007, from 3rd July, for biomedical research (BOE n 159), which protects the rights of individuals who are subjects of research. Clinical trials should be registered with public databases prior to their initiation and patient recruitment, and only after approval of the institutional or regional Clinical Research Ethics Committee. The authors should provide the archive number and database where the trial is registered. For all clinical trials that initiate patient recruitment as of 1 January 2017, registration in public databases will be mandatory. Trials with patient recruitment prior to this date may still be submitted to the Journal for evaluation.

USE OF PUBLISHING GUIDELINES

When preparing articles, the international guidelines should be followed in order to express health research results and apply them to the specific type of study. Authors must provide a check-list, indicating the page number of the manuscript that refers to each section of the guidelines. This check-list will make it easier to review, but it will not be published with the work.

EQUATOR contains an introduction and several aids (toolkits) for authors and manuscript reviewers. Some are also in Spanish. Each type of article requires specific guidelines:

Clinical trials: CONSORT. These guidelines are required, with the flow diagram being included in the manuscript, as well as its adjustment to non-pharmacological treatments. The check-list will be provided on the last page of the manuscript.

Observational studies: STROBE following the checklist appropriate to the type of study (cohort, case-control, or cross-sectional), and including the flow diagram in the manuscript. The checklist will be provided on the last page of the manuscript.

Diagnostic tests: STARD, including the checklist on the last page of the manuscript.

Systematic reviews and meta-analysis: PRISMA, including the flow diagram in the manuscript, and providing the check-list on the last page of the manuscript.

Qualitative studies and focus groups: COREQ.

Studies on quality improvement: SQUIRE.

For other types of studies, consult EQUATOR.

Any article submitted to this journal must include a series of statements both on the title page and within the body of the article in certain cases. Statements will be required even if they are also requested on the submission platform, or if the author believes they do not exist or are not applicable.

TITLE PAGE

The following statements must be included on the title page:

Ethical considerations

Any article that includes experiments involving human subjects will require a statement from the author confirming that all procedures were conducted in accordance with the Declaration of Helsinki, relevant laws, and institutional guidelines. The study’s ethical approval reference number should be included in works involving human experimentation. When experimentation involves animals, compliance with the relevant regulations must also be noted.

This is a mandatory statement for Original Articles, Short Originals.

Depending on the nature of Special Articles and Protocols, an ethical statement may be required. Authors of Special Articles and Protocols must always include a statement one way or another: that it has been obtained or that it is not applicable. While systematic reviews do not require ethical approval, they must be based on original research that does meet those ethical requirements.

Informed consent

It must be stated that there are no patient data in the article, and if there are, that they do not violate the privacy and confidentiality of the patient, nor allow for their identification, and that in any case, informed consent for participation in research and for the presentation of results in a publication is in place.

The rights of privacy of human subjects must always be respected. Appropriate consents and permissions must be obtained when presenting one or more cases (anonymised) without experimentation or when an author wishes to include details or other personal information or images of patients and any other individuals in an Elsevier publication. Isolated data such as age, sex, service, or institution presented together can breach patient privacy and confidentiality. Images accompanied by any patient data always require a statement.

The author will retain written consents and provide Elsevier with copies of the consents or proof of their acquisition when requested.

When Original research refers to retrospective studies where obtaining informed consent is not possible, the author must obtain exemption from this statement from their institution's Ethics Committee to proceed with the research.

This is a mandatory statement for Original Articles, Short Originals, Clinical Eye, Scientific-Clinical Letters. While systematic reviews do not require informed consent, they must be based on original research that does comply with this requirement.

Funding

The author will identify who provided financial support for the research and/or preparation of the article and briefly describe the role of the sponsor(s), if applicable, in the study design; in the collection, analysis, and interpretation of data; in the drafting of the report; and in the decision to submit the article for publication. If the funding source(s) did not have such involvement, this should be declared.

This is a mandatory statement for all sections. In the absence of funding, it should state: “Funding: none.”

Conflict of interests

Any financial or personal relationships with other people or organisations that may have influenced the work must be specified, even if not directly related to the current manuscript. Examples of potential competing interests include employment, consultancy, share ownership, fees, paid expert testimony, patent applications/registrations, and other funding, as well as travel grants and participation in courses and conferences as a paid expert.

If a member of the Editorial Board contributes as an author to any manuscript submitted to the Journal, the responsible editor must include the following statement in the conflict of interest section: “As ABC is a member of the Editorial Board of the Journal, they have not participated in or had access to information regarding the review and acceptance process of the manuscript.”

This statement is always mandatory. There will be a statement from each of the participating authors. In the absence of any conflict, it should state: "Conflict of interest: none."

Use of generative artificial intelligence in scientific writing Single permitted use.

Please see the description further down in these guidelines.

Mandatory statement whenever it is used.

Authorship

All authors must have made substantial contributions in each of the following aspects: (1) the conception and design of the study, or the acquisition of data, or the analysis and interpretation of data, (2) drafting the article or critically revising its intellectual content, (3) final approval of the version to be submitted. No changes to authorship or alterations to the order of authors may be made once the article has been submitted without prior justification and approval from the Chief Editor.

BODY OF THE ARTICLE

In cases where experiments are conducted with animals or human subjects, certain statements must be included within the manuscript even if they are also required on the submission platform or on the title page. These statements will always be declared in Original Articles or Short Originals, regardless of whether the author believes they do not exist or are not applicable.

Ethics and informed consent

In the case of experiments involving human or animal subjects, the author must declare in the materials and methods section (of the originals, short originals, or case series articles) that the guidelines on Human and Animal Rights described in the "Ethics in Publishing" section of this author guideline have been followed. In particular, if human experimentation is involved, the authors will confirm that the research has been conducted in accordance with the ethical code of the World Medical Association (Declaration of Helsinki), and in the case of animals, that the ARRIVE guidelines have been followed or that they are acting in accordance with the Animal Welfare Act and, where applicable, the Animal Welfare Act. The authors must also declare in the materials and methods section (original or short original) that they have obtained informed consent and approval from the Clinical Research Ethics Committee (CREC) or the relevant committee without revealing data that would hinder blind evaluation. Please note that Spanish Biomedical Research Law stipulates that the Ethics Committees for Research corresponding to each institution must evaluate all biomedical research involving interventions in humans or the use of their biological samples.

Appropriate consents and permissions must be obtained when presenting one or more cases without experimentation or when an author wishes to include details or other personal information or images of patients and any other individuals in an Elsevier publication. The author will retain written consent forms and provide Elsevier with copies of the consent forms or evidence of their acquisition upon request.

ORIGINAL ARTICLES

Clinical or experimental studies, randomised clinical trials, cohort studies, screening studies or diagnostic tests, cost-effectiveness analyses, decision-making evaluation studies, interventional studies, case-control studies, and survey-based studies with a high response rate will be considered. They may cover any field related to Internal Medicine, with particular emphasis on their clinical relevance.

Occasionally, study protocols that are deemed relevant, innovative, and potentially citable may be accepted for publication, subject to evaluation by the Editorial Committee. The topics of the articles may cover any field related to Medicine, with particular emphasis on their clinical relevance.

They will have a maximum length of 4,000 words, excluding the title page or first page with its statements, the structured abstract of 250 words, keywords, figure legends, and references (maximum 50). A maximum of 6 tables or figures will be allowed. The number of authors will not exceed 10 but may increase if the corresponding author provides justification and in cases of collaborative studies. Preparation of a graphical abstract summarising the most important aspects of the manuscript will be mandatory; the author may submit it initially or when they know their article will be accepted. You can find information for creating it at (https://www.elsevier.com/researcher/author/tools-and-resources/graphical-abstract). But, please, use this template: https://static.elsevier.es/miscelanea/revclinesp_ga.pptx

Revista Clínica Española requires registration of all clinical trials that have been published, as well as acceptance of the studies by the relevant ethics committees. For the preparation of controlled clinical trials, the CONSORT guidelines must be followed, available at: http://www.consort-statement.org/. In the case of observational studies, the points outlined in the checklist available at: http://www.strobe-statement.org/ must be followed. For studies on the validity of diagnostic tests, the STARD guidelines available at: http://www.stard-statement.org/ must be adhered to.

Systematic reviews may or may not use statistical methods (meta-analysis) to analyse and summarise the results of the included studies. The PRISMA guidelines will be followed, available at: http://prisma-statement.org/.

The required statements will be included on the title page or first page.

SHORT ORIGINALS

These will be considered research works that, due to their characteristics, may be published in abbreviated form. They will be structured like original articles. The length will not exceed 1,500 words, excluding the title page or first page with its statements, the abstract (of 150 words), keywords, figure legends, and references (no more than 20). Up to 2 figures or tables may be included. The number of authors will not exceed 8. Preparation of a graphical abstract summarising the most important aspects of the manuscript will be mandatory; the author may submit it initially or when they know their article will be accepted. Information for creating it can be found at (https://www.elsevier.com/researcher/author/tools-and-resources/graphical-abstract). But, please, use this template: https://static.elsevier.es/miscelanea/revclinesp_ga.pptx

The required statements will be included on the title page or first page.

REVIEW

This section will feature commissioned articles on topics that the Editorial Committee considers relevant and worthy of updating knowledge. It may appear in one of the following formats:

1. A narrative clinical review with a maximum length of 4,000 words in the manuscript, excluding the title page or first page with statements, an unstructured abstract of 150 words, keywords, bibliography (maximum 80 references), and figure legends. Up to 4 tables or figures may be included;

2. A brief clinical review with a maximum length of 2,000 words in the manuscript, excluding the title page or first page with statements, an unstructured abstract of 150 words, keywords, bibliography (maximum 50 references), and figure legends. Up to 2 tables or figures may be included.

The maximum number of authors will be 4 for either format. Any author may submit unsolicited manuscripts for consideration in this section, subject to prior contact and acceptance of the topic by the Editorial Team.

The required statements will be included on the title page or first page.

THE CLINICAL EYE

This section will publish an image that has high educational or training value on its own. The image must be detailed and accompanied by arrows or symbols for clarification. A maximum of 3 authors and 150 words (excluding the title) may be included, as well as 2 references at the authors' discretion (not mandatory).

The required statements will be included on the title page or first page.

SCIENTIFIC LETTERS

These will consist of observations or experiences that can be summarised in a brief text and communicated concisely. A maximum of 750 words, 1 figure or table, and up to 15 bibliographic citations will be permitted, with a maximum of 4 authors.

The required statements will be included on the title page or first page.

LETTERS TO THE EDITOR

These will be objections or comments on articles recently published in the Journal. Letters regarding articles previously published in the Journal will take precedence for publication, as well as the right to reply. These letters will be shorter, with a maximum of 300 words and 5 bibliographic references; they must not reference unpublished personal studies or experiences. They will be sent to the author of the original work, who may respond in a similarly sized written piece within a month. The Letter and the reply will be published continuously.

The required statements will be included on the title page or first page.

SPECIAL ARTICLES

This section aims to accommodate manuscripts that, due to their unique content, cannot be included in other sections. They will have a maximum length of 2,000 words, excluding the title page or first page where the required statements will be included, the unstructured abstract of 150 words, keywords, and a maximum of 40 bibliographic citations. Up to 3 tables or figures may be included. The maximum number of authors will be 3.

The required statements will be included on the title page or first page.

CONSENSUS DOCUMENTS The submission of the final manuscript for evaluation in Revista Clínica Española must be accompanied by the corresponding authorisation from the Board of Directors of the Spanish Society of Internal Medicine, as well as from any other societies that may be represented in the document. Ideally, consensus works with a multidisciplinary perspective will be valued, including specialists who typically address a particular pathology. The required statements must be included on the title page or first page of the manuscript. The journal will publish the accepted consensus document as an Executive Summary. The aim of publishing the Executive Summary is to provide readers with a synthesis of the consensus document, while offering sufficient detail and clarity to understand the scope and most relevant points of the complete document. The following guidelines should be followed for its preparation:

1. Title in Spanish and English. It should preferably begin with the phrase: "Executive summary of the consensus document on..."

2. Maximum of 10 authors. The authorship of a working group may be included as an annex at the end of the manuscript. Professional affiliations are required for all authors.

3. Summary in Spanish and English. Maximum of 150 words.

4. Keywords in Spanish and English according to MeSH.

5. The body of the executive summary will have a maximum length of 3,000 words:

   • An introduction describing the need or rationale for the document.

   • A methods section explaining how the consensus document was created, how the points to be addressed were selected, and whether there was any discussion or agreement on each point and what the percentage of agreement was.

   • A results section highlighting the most significant aspects of the document.

   • A brief discussion on the applicability, limitations, and implications of the document.

   • Reference to the complete document in one of the sections, accessible via a link.

   • Bibliography (maximum of 15 citations) following the guidelines of Revista Clínica Española.

   • Tables and figures that aid in interpreting the information clearly and concisely.

6. Each component of the executive summary must be uploaded to the RCE platform, along with associated documents or additional material, including the complete document that will be published as an annex.

The required statements will be included on the title page or first page.

EDITORIALS

These will be commissioned, although unsolicited editorials may occasionally be considered after prior consultation with the Editor. The text is limited to a maximum of 1,500 words. No tables or figures are permitted, but a graphical abstract summarising the most important aspects of the manuscript is recommended. Up to 15 references will be accepted. Up to 2 authors will be permitted.

The required statements will be included on the title page or first page.

All manuscripts must be submitted online at https://www.editorialmanager.com/rce.

This journal is published in Spanish and in English language

You can use this list to carry out a final check of your submission before you send it to the journal for review. Please check the relevant section in this Guide for Authors for more details.

Ensure that the following items are present:

One author has been designated as the corresponding author with contact details:

• E-mail address

• Full postal address

All necessary files have been uploaded:

Manuscript

• Include keywords

• All figures (include relevant captions)

• All tables (including titles, description, footnotes)

• Ensure all figure and table citations in the text match the files provided; Indicate clearly if color should be used for any figures in print

Graphical Abstracts / Highlights files (where applicable)

Supplemental files (where applicable)

Further considerations:

• Manuscript has been 'spell checked' and 'grammar checked'

• All references mentioned in the Reference List are cited in the text, and vice versa

• Permission has been obtained for use of copyrighted material from other sources (including the Internet)

• A competing interests statement is provided, even if the authors have no competing interests to declare

• Journal policies detailed in this guide have been reviewed

For further information, visit our Support Center.

Please see our information on Ethics in publishing.

If the work involves the use of human subjects, the author should ensure that the work described has been carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. The manuscript should be in line with the Recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals and aim for the inclusion of representative human populations (sex, age and ethnicity) as per those recommendations. The terms sex and gender should be used correctly.

The author should ensure that the manuscript contains a statement that all procedures were performed in compliance with relevant laws and institutional guidelines and have been approved by the appropriate institutional committee(s). This statement should contain the date and reference number of the ethical approval(s) obtained. Authors should also include a statement in the manuscript that informed consent was obtained for experimentation with human subjects. The privacy rights of human subjects must always be observed.

The journal will not accept manuscripts that contain data derived from unethically sourced organs or tissue, including from executed prisoners or prisoners of conscience, consistent with recommendations by Global Rights Compliance on Mitigating Human Rights Risks in Transplantation Medicine. For all studies that use human organs or tissues authors must provide sufficient evidence that they were procured in line with WHO Guiding Principles on Human Cell, Tissue and Organ Transplantation. The source of the organs or tissues used in clinical research must be transparent and traceable. Authors of manuscripts describing organ transplantation must additionally declare within the manuscript:

1. that autonomous consent free from coercion was obtained from the donor(s) or their next of kin; and

2. that organs/tissues were not sourced from executed prisoners or prisoners of conscience.

All animal experiments should comply with the ARRIVE guidelines and should be carried out in accordance with the U.K. Animals (Scientific Procedures) Act, 1986 and associated guidelines, EU Directive 2010/63/EU for animal experiments, or the National Research Council's Guide for the Care and Use of Laboratory Animals and the authors should clearly indicate in the manuscript that such guidelines have been followed. The sex of animals must be indicated, and where appropriate, the influence (or association) of sex on the results of the study.

Studies on patients or volunteers (including organ/tissue donors) require informed consent, which should be documented in the paper. Appropriate consents, permissions and releases must be obtained where an author wishes to include case details or other personal information or images of patients and any other individuals in an Elsevier publication. Written consents must be retained by the author, but copies should not be provided to the journal.

Only if specifically requested by the journal in exceptional circumstances (for example if a legal issue arises) the author must provide copies of the consents or evidence that such consents have been obtained. For more information, please review the Elsevier Policy on the Use of Images or Personal Information of Patients or other Individuals.

Unless the author has written permission from the patient (or, where applicable, the next of kin), the personal details of any patient included in any part of the article and in any supplementary materials (including all illustrations and videos) must be removed before submission.

All authors must disclose any financial and personal relationships with other people or organizations that could inappropriately influence (bias) their work. Examples of potential competing interests include employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, and grants or other funding. Authors must disclose any interests in two places: 1. A summary declaration of interest statement in the title page file (if double anonymized) or the manuscript file (if single anonymized). If there are no interests to declare then please state this: 'Declarations of interest: none'. 2. Detailed disclosures as part of a separate Declaration of Interest form, which forms part of the journal's official records. It is important for potential interests to be declared in both places and that the information matches. More information.

The below guidance only refers to the writing process, and not to the use of AI tools to analyse and draw insights from data as part of the research process.

Where authors use generative artificial intelligence (AI) and AI-assisted technologies in the writing process, authors should only use these technologies to improve readability and language. Applying the technology should be done with human oversight and control, and authors should carefully review and edit the result, as AI can generate authoritative-sounding output that can be incorrect, incomplete or biased. AI and AI-assisted technologies should not be listed as an author or co-author, or be cited as an author. Authorship implies responsibilities and tasks that can only be attributed to and performed by humans, as outlined in Elsevier's AI policy for authors.

Authors should disclose in their manuscript the use of AI and AI-assisted technologies in the writing process by following the instructions below. A statement will appear in the published work. Please note that authors are ultimately responsible and accountable for the contents of the work.

Disclosure instructions

Authors must disclose the use of generative AI and AI-assisted technologies in the writing process by adding a statement at the end of their manuscript in the core manuscript file, before the References list. The statement should be placed in a new section entitled 'Declaration of Generative AI and AI-assisted technologies in the writing process'

Statement: During the preparation of this work the author(s) used [NAME TOOL / SERVICE] in order to [REASON]. After using this tool/service, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the publication

This declaration does not apply to the use of basic tools for checking grammar, spelling, references etc. If there is nothing to disclose, there is no need to add a statement.

Submission of an article implies that the work described has not been published previously (except in the form of an abstract, a published lecture or academic thesis, see 'Multiple, redundant or concurrent publication' for more information), that it is not under consideration for publication elsewhere, that its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form, in English or in any other language, including electronically without the written consent of the copyright-holder. To verify compliance, your article may be checked by Crossref Similarity Check and other originality or duplicate checking software.

Inclusive language acknowledges diversity, conveys respect to all people, is sensitive to differences, and promotes equal opportunities. Content should make no assumptions about the beliefs or commitments of any reader; contain nothing which might imply that one individual is superior to another on the grounds of age, gender, race, ethnicity, culture, sexual orientation, disability or health condition; and use inclusive language throughout. Authors should ensure that writing is free from bias, stereotypes, slang, reference to dominant culture and/or cultural assumptions. We advise to seek gender neutrality by using plural nouns ("clinicians, patients/clients") as default/wherever possible to avoid using "he, she," or "he/she." We recommend avoiding the use of descriptors that refer to personal attributes such as age, gender, race, ethnicity, culture, sexual orientation, disability or health condition unless they are relevant and valid. When coding terminology is used, we recommend to avoid offensive or exclusionary terms such as "master", "slave", "blacklist" and "whitelist". We suggest using alternatives that are more appropriate and (self-) explanatory such as "primary", "secondary", "blocklist" and "allowlist". These guidelines are meant as a point of reference to help identify appropriate language but are by no means exhaustive or definitive.

Reporting guidance

For research involving or pertaining to humans, animals or eukaryotic cells, investigators should integrate sex and gender-based analyses (SGBA) into their research design according to funder/sponsor requirements and best practices within a field. Authors should address the sex and/or gender dimensions of their research in their article. In cases where they cannot, they should discuss this as a limitation to their research's generalizability. Importantly, authors should explicitly state what definitions of sex and/or gender they are applying to enhance the precision, rigor and reproducibility of their research and to avoid ambiguity or conflation of terms and the constructs to which they refer (see Definitions section below). Authors can refer to the Sex and Gender Equity in Research (SAGER) guidelines and the SAGER guidelines checklist. These offer systematic approaches to the use and editorial review of sex and gender information in study design, data analysis, outcome reporting and research interpretation - however, please note there is no single, universally agreed-upon set of guidelines for defining sex and gender.

Definitions

Sex generally refers to a set of biological attributes that are associated with physical and physiological features (e.g., chromosomal genotype, hormonal levels, internal and external anatomy). A binary sex categorization (male/female) is usually designated at birth ("sex assigned at birth"), most often based solely on the visible external anatomy of a newborn. Gender generally refers to socially constructed roles, behaviors, and identities of women, men and gender-diverse people that occur in a historical and cultural context and may vary across societies and over time. Gender influences how people view themselves and each other, how they behave and interact and how power is distributed in society. Sex and gender are often incorrectly portrayed as binary (female/male or woman/man) and unchanging whereas these constructs actually exist along a spectrum and include additional sex categorizations and gender identities such as people who are intersex/have differences of sex development (DSD) or identify as non-binary. Moreover, the terms "sex" and "gender" can be ambiguous--thus it is important for authors to define the manner in which they are used. In addition to this definition guidance and the SAGER guidelines, the resources on this page offer further insight around sex and gender in research studies.

All authors should have made substantial contributions to all of the following: (1) the conception and design of the study, or acquisition of data, or analysis and interpretation of data, (2) drafting the article or revising it critically for important intellectual content, (3) final approval of the version to be submitted.

Authors are expected to consider carefully the list and order of authors before submitting their manuscript and provide the definitive list of authors at the time of the original submission. Any addition, deletion or rearrangement of author names in the authorship list should be made only before the manuscript has been accepted and only if approved by the journal Editor. To request such a change, the Editor must receive the following from the corresponding author: (a) the reason for the change in author list and (b) written confirmation (e-mail, letter) from all authors that they agree with the addition, removal or rearrangement. In the case of addition or removal of authors, this includes confirmation from the author being added or removed.

Only in exceptional circumstances will the Editor consider the addition, deletion or rearrangement of authors after the manuscript has been accepted. While the Editor considers the request, publication of the manuscript will be suspended. If the manuscript has already been published in an online issue, any requests approved by the Editor will result in a corrigendum.

In line with the position of the International Committee of Medical Journal Editors, the journal will not consider results posted in the same clinical trials registry in which primary registration resides to be prior publication if the results posted are presented in the form of a brief structured (less than 500 words) abstract or table. However, divulging results in other circumstances (e.g., investors' meetings) is discouraged and may jeopardise consideration of the manuscript. Authors should fully disclose all posting in registries of results of the same or closely related work.

Randomized controlled trials should be presented according to the CONSORT guidelines. At manuscript submission, authors must provide the CONSORT checklist accompanied by a flow diagram that illustrates the progress of patients through the trial, including recruitment, enrolment, randomization, withdrawal and completion, and a detailed description of the randomization procedure. The CONSORT checklist and template flow diagram are available online.

Registration in a public trials registry is a condition for publication of clinical trials in this journal in accordance with International Committee of Medical Journal Editors recommendations. Trials must register at or before the onset of patient enrolment. The clinical trial registration number should be included at the end of the abstract of the article. A clinical trial is defined as any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects of health outcomes. Health-related interventions include any intervention used to modify a biomedical or health-related outcome (for example drugs, surgical procedures, devices, behavioural treatments, dietary interventions, and process-of-care changes). Health outcomes include any biomedical or health-related measures obtained in patients or participants, including pharmacokinetic measures and adverse events. Purely observational studies (those in which the assignment of the medical intervention is not at the discretion of the investigator) will not require registration.

Upon acceptance of an article, authors will be asked to complete a 'Journal Publishing Agreement' (see more information on this). An e-mail will be sent to the corresponding author confirming receipt of the manuscript together with a 'Journal Publishing Agreement' form or a link to the online version of this agreement.

Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institutions. Permission of the Publisher is required for resale or distribution outside the institution and for all other derivative works, including compilations and translations. If excerpts from other copyrighted works are included, the author(s) must obtain written permission from the copyright owners and credit the source(s) in the article. Elsevier has preprinted forms for use by authors in these cases.

For gold open access articles: Upon acceptance of an article, authors will be asked to complete a 'License Agreement' (more information). Permitted third party reuse of gold open access articles is determined by the author's choice of user license.

Author rights

As an author you (or your employer or institution) have certain rights to reuse your work. More information.

Find out how you can share your research published in Elsevier journals.

You are requested to identify who provided financial support for the conduct of the research and/or preparation of the article and to briefly describe the role of the sponsor(s), if any, in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. If the funding source(s) had no such involvement, it is recommended to state this.

Please visit our Open Access page for more information about open access publishing in this journal.

Researcher Academy is a free e-learning platform designed to support early and mid-career researchers throughout their research journey. The "Learn" environment at Researcher Academy offers several interactive modules, webinars, downloadable guides and resources to guide you through the process of writing for research and going through peer review. Feel free to use these free resources to improve your submission and navigate the publication process with ease.

Please write your text in good English (American or British usage is accepted, but not a mixture of these). Authors who feel their English language manuscript may require editing to eliminate possible grammatical or spelling errors and to conform to correct scientific English may wish to use the Language Editing service available from Elsevier's Language Services.

Our online submission system guides you stepwise through the process of entering your article details and uploading your files. The system converts your article files to a single PDF file used in the peer-review process. Editable files (e.g., Word, LaTeX) are required to typeset your article for final publication. All correspondence, including notification of the Editor's decision and requests for revision, is sent by e-mail.

Please submit your article via https://www.editorialmanager.com/rce.

Please submit the names and institutional e-mail addresses of several potential reviewers.

You should not suggest reviewers who are colleagues, or who have co-authored or collaborated with you during the last three years. Editors do not invite reviewers who have potential competing interests with the authors. Further, in order to provide a broad and balanced assessment of the work, and ensure scientific rigor, please suggest diverse candidate reviewers who are located in different countries/regions from the author group. Also consider other diversity attributes e.g. gender, race and ethnicity, career stage, etc. Finally, you should not include existing members of the journal's editorial team, of whom the journal are already aware.

Note: the editor decides whether or not to invite your suggested reviewers.

This journal operates a double anonymized review process. All contributions will be initially assessed by the editor for suitability for the journal. Papers deemed suitable are then typically sent to a minimum of two independent expert reviewers to assess the scientific quality of the paper. The Editor is responsible for the final decision regarding acceptance or rejection of articles. The Editor's decision is final. Editors are not involved in decisions about papers which they have written themselves or have been written by family members or colleagues or which relate to products or services in which the editor has an interest. Any such submission is subject to all of the journal's usual procedures, with peer review handled independently of the relevant editor and their research groups. More information on types of peer review.

This journal uses double anonymized review, which means the identities of the authors are concealed from the reviewers, and vice versa. More information is available on our website. To facilitate this, please include the following separately:

Title page (with author details): This should include the title, authors' names, affiliations, acknowledgements and any Declaration of Interest statement, and a complete address for the corresponding author including an e-mail address.

Anonymized manuscript (no author details): The main body of the paper (including the references, figures, tables and any acknowledgements) should not include any identifying information, such as the authors' names or affiliations.

It is important that the file be saved in the native format of the word processor used. The text should be in single-column format. Keep the layout of the text as simple as possible. Most formatting codes will be removed and replaced on processing the article. In particular, do not use the word processor's options to justify text or to hyphenate words. However, do use bold face, italics, subscripts, superscripts etc. When preparing tables, if you are using a table grid, use only one grid for each individual table and not a grid for each row. If no grid is used, use tabs, not spaces, to align columns. The electronic text should be prepared in a way very similar to that of conventional manuscripts (see also the Guide to Publishing with Elsevier. Note that source files of figures, tables and text graphics will be required whether or not you embed your figures in the text. See also the section on Electronic artwork.

To avoid unnecessary errors you are strongly advised to use the 'spell-check' and 'grammar-check' functions of your word processor.

This section describes the article structure for this journal.

Divide your article into clearly defined sections. Each subsection is given a brief heading. Each heading should appear on its own separate line. Subsections should be used as much as possible when cross-referencing text: refer to the subsection by heading as opposed to simply 'the text'.

State the objectives of the work and provide an adequate background, avoiding a detailed literature survey or a summary of the results.

Provide sufficient details to allow the work to be reproduced by an independent researcher. Methods that are already published should be summarized, and indicated by a reference. If quoting directly from a previously published method, use quotation marks and also cite the source. Any modifications to existing methods should also be described.

Results should be clear and concise.

This should explore the significance of the results of the work, not repeat them. A combined Results and Discussion section is often appropriate. Avoid extensive citations and discussion of published literature.

The main conclusions of the study may be presented in a short Conclusions section, which may stand alone or form a subsection of a Discussion or Results and Discussion section.

If there is more than one appendix, they should be identified as A, B, etc. Formulae and equations in appendices should be given separate numbering: Eq. (A.1), Eq. (A.2), etc.; in a subsequent appendix, Eq. (B.1) and so on. Similarly for tables and figures: Table A.1; Fig. A.1, etc.

• Title. Concise and informative. Titles are often used in information-retrieval systems. Avoid abbreviations and formulae where possible.

• Author names and affiliations. Please clearly indicate the given name(s) and family name(s) of each author and check that all names are accurately spelled. You can add your name between parentheses in your own script behind the English transliteration. Present the authors' affiliation addresses (where the actual work was done) below the names. Indicate all affiliations with a lower-case superscript letter immediately after the author's name and in front of the appropriate address. Provide the full postal address of each affiliation, including the country name and, if available, the e-mail address of each author.

• Corresponding author. Clearly indicate who will handle correspondence at all stages of refereeing and publication, also post-publication. This responsibility includes answering any future queries about Methodology and Materials. Ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author.

• Present/permanent address. If an author has moved since the work described in the article was done, or was visiting at the time, a 'Present address' (or 'Permanent address') may be indicated as a footnote to that author's name. The address at which the author actually did the work must be retained as the main, affiliation address. Superscript Arabic numerals are used for such footnotes.

Highlights are optional yet highly encouraged for this journal, as they increase the discoverability of your article via search engines. They consist of a short collection of bullet points that capture the novel results of your research as well as new methods that were used during the study (if any). Please have a look at the example Highlights.

Highlights should be submitted in a separate editable file in the online submission system. Please use 'Highlights' in the file name and include 3 to 5 bullet points (maximum 85 characters, including spaces, per bullet point).

A structured abstract, by means of appropriate headings, should provide the context or background for the research and should state its purpose, basic procedures (selection of study subjects or laboratory animals, observational and analytical methods), main findings (giving specific effect sizes and their statistical significance, if possible), and principal conclusions. It should emphasize new and important aspects of the study or observations.

The headings will consist of: «Introduction and Objectives», «Patients or Materials and Methods», «Results» y «Conclusions».

Although a graphical abstract is optional, its use is encouraged as it draws more attention to the online article. The graphical abstract should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership. Graphical abstracts should be submitted as a separate file in the online submission system. Image size: Please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. The image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. Preferred file types: TIFF, EPS, PDF or MS Office files. You can view Example Graphical Abstracts on our information site.

Immediately after the abstract, provide a maximum of 6 keywords, using British spelling and avoiding general and plural terms and multiple concepts (avoid, for example, 'and', 'of'). Be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. To maximise discoverability, use terms and words that are not already in the manuscript's title and abstract as keywords. Consider the terms that potential readers may use to search for work on this topic that do not already appear in the title and abstract. Include synonyms and related terms to cover different variations of how readers might search for your topic. Specific keywords target niche audiences, while broad keywords increase the chances of your article reaching a wider audience. These keywords will be used for indexing purposes.

Define abbreviations that are not standard in this field in a footnote to be placed on the first page of the article. Such abbreviations that are unavoidable in the abstract must be defined at their first mention there, as well as in the footnote. Ensure consistency of abbreviations throughout the article.

Collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. List here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.).

List funding sources in this standard way to facilitate compliance to funder's requirements:

Funding: This work was supported by the National Institutes of Health [grant numbers xxxx, yyyy]; the Bill & Melinda Gates Foundation, Seattle, WA [grant number zzzz]; and the United States Institutes of Peace [grant number aaaa].

It is not necessary to include detailed descriptions on the program or type of grants and awards. When funding is from a block grant or other resources available to a university, college, or other research institution, submit the name of the institute or organization that provided the funding.

If no funding has been provided for the research, it is recommended to include the following sentence:

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Follow internationally accepted rules and conventions: use the international system of units (SI). If other units are mentioned, please give their equivalent in SI.

This section describes the artwork for this journal.

Whilst it is accepted that authors sometimes need to manipulate images for clarity, manipulation for purposes of deception or fraud will be seen as scientific ethical abuse and will be dealt with accordingly. For graphical images, this journal is applying the following policy: no specific feature within an image may be enhanced, obscured, moved, removed, or introduced. Adjustments of brightness, contrast, or color balance are acceptable if and as long as they do not obscure or eliminate any information present in the original. Nonlinear adjustments (e.g. changes to gamma settings) must be disclosed in the figure legend.

General points

• Make sure you use uniform lettering and sizing of your original artwork.

• Embed the used fonts if the application provides that option.

• Aim to use the following fonts in your illustrations: Arial, Courier, Times New Roman, Symbol, or use fonts that look similar.

• Number the illustrations according to their sequence in the text.

• Use a logical naming convention for your artwork files.

• Provide captions to illustrations separately.

• Size the illustrations close to the desired dimensions of the published version.

• Submit each illustration as a separate file.

• Ensure that color images are accessible to all, including those with impaired color vision.

A detailed guide on electronic artwork is available.

You are urged to visit this site; some excerpts from the detailed information are given here.

Formats

If your electronic artwork is created in a Microsoft Office application (Word, PowerPoint, Excel) then please supply 'as is' in the native document format.

Regardless of the application used other than Microsoft Office, when your electronic artwork is finalized, please 'Save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below):

EPS (or PDF): Vector drawings, embed all used fonts.

TIFF (or JPEG): Color or grayscale photographs (halftones), keep to a minimum of 300 dpi.

TIFF (or JPEG): Bitmapped (pure black & white pixels) line drawings, keep to a minimum of 1000 dpi.

TIFF (or JPEG): Combinations bitmapped line/half-tone (color or grayscale), keep to a minimum of 500 dpi.

Please do not:

• Supply files that are optimized for screen use (e.g., GIF, BMP, PICT, WPG); these typically have a low number of pixels and limited set of colors;

• Supply files that are too low in resolution;

• Submit graphics that are disproportionately large for the content.

Please make sure that artwork files are in an acceptable format (TIFF (or JPEG), EPS (or PDF) or MS Office files) and with the correct resolution. If, together with your accepted article, you submit usable color figures then Elsevier will ensure, at no additional charge, that these figures will appear in color online (e.g., ScienceDirect and other sites). Further information on the preparation of electronic artwork.

Ensure that each illustration has a caption. Supply captions separately, not attached to the figure. A caption should comprise a brief title (not on the figure itself) and a description of the illustration. Keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used.

Please submit tables as editable text and not as images. Tables can be placed either next to the relevant text in the article, or on separate page(s) at the end. Number tables consecutively in accordance with their appearance in the text and place any table notes below the table body. Be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. Please avoid using vertical rules and shading in table cells.

This section describes the references for this journal.

Please ensure that every reference cited in the text is also present in the reference list (and vice versa). Any references cited in the abstract must be given in full. Unpublished results and personal communications are not recommended in the reference list, but may be mentioned in the text. If these references are included in the reference list they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'Unpublished results' or 'Personal communication'. Citation of a reference as 'in press' implies that the item has been accepted for publication.

Increased discoverability of research and high quality peer review are ensured by online links to the sources cited. In order to allow us to create links to abstracting and indexing services, such as Scopus, Crossref and PubMed, please ensure that data provided in the references are correct. Please note that incorrect surnames, journal/book titles, publication year and pagination may prevent link creation. When copying references, please be careful as they may already contain errors. Use of the DOI is highly encouraged.

A DOI is guaranteed never to change, so you can use it as a permanent link to any electronic article. An example of a citation using DOI for an article not yet in an issue is: VanDecar J.C., Russo R.M., James D.E., Ambeh W.B., Franke M. (2003). Aseismic continuation of the Lesser Antilles slab beneath northeastern Venezuela. Journal of Geophysical Research, https://doi.org/10.1029/2001JB000884. Please note the format of such citations should be in the same style as all other references in the paper.

As a minimum, the full URL should be given and the date when the reference was last accessed. Any further information, if known (DOI, author names, dates, reference to a source publication, etc.), should also be given. Web references can be listed separately (e.g., after the reference list) under a different heading if desired, or can be included in the reference list.

This journal encourages you to cite underlying or relevant datasets in your manuscript by citing them in your text and including a data reference in your Reference List. Data references should include the following elements: author name(s), dataset title, data repository, version (where available), year, and global persistent identifier. Add [dataset] immediately before the reference so we can properly identify it as a data reference. The [dataset] identifier will not appear in your published article.

Where a preprint has subsequently become available as a peer-reviewed publication, the formal publication should be used as the reference. If there are preprints that are central to your work or that cover crucial developments in the topic, but are not yet formally published, these may be referenced. Preprints should be clearly marked as such, for example by including the word preprint, or the name of the preprint server, as part of the reference. The preprint DOI should also be provided.

Please ensure that the words 'this issue' are added to any references in the list (and any citations in the text) to other articles in the same Special Issue.

Most Elsevier journals have their reference template available in many of the most popular reference management software products. These include all products that support Citation Style Language styles, such as Mendeley. Using citation plug-ins from these products, authors only need to select the appropriate journal template when preparing their article, after which citations and bibliographies will be automatically formatted in the journal's style. If no template is yet available for this journal, please follow the format of the sample references and citations as shown in this Guide. If you use reference management software, please ensure that you remove all field codes before submitting the electronic manuscript. More information on how to remove field codes from different reference management software.

Text: Indicate references by superscript numbers in the text. The actual authors can be referred to, but the reference number(s) must always be given.

List: Number the references in the list in the order in which they appear in the text.

Examples:

Reference to a journal publication:

1. Van der Geer J, Hanraads JAJ, Lupton RA. The art of writing a scientific article. J Sci Commun 2010; 163 :51-9. https://doi.org/10.1016/j.Sc.2010.00372.

Reference to a journal publication with an article number:

2. Van der Geer J, Hanraads JAJ, Lupton RA. The art of writing a scientific article. Heliyon. 2018;19:e00205. https://doi.org/j.heliyon.2018.e00205.

Reference to a book:

3. Strunk Jr W, White EB. The elements of style. 4th ed. New York: Longman; 2000.

Reference to a chapter in an edited book:

4. Mettam GR, Adams LB. How to prepare an electronic version of your article. In: Jones BS, Smith RZ, editors. Introduction to the electronic age, New York: E-Publishing Inc; 2009, p. 281-304.

Reference to a website:

5. Cancer Research UK. Cancer statistics reports for the UK, http://www.cancerresearchuk.org/aboutcancer/statistics/cancerstatsreport/; 2003 [accessed 13 March 2003].

Reference to a dataset:

[dataset] 6. Oguro M, Imahiro S, Saito S, Nakashizuka T. Mortality data for Japanese oak wilt disease and surrounding forest compositions, Mendeley Data, v1; 2015. https://doi.org/10.17632/xwj98nb39r.1.

Note shortened form for last page number. e.g., 51-9, and that for more than 6 authors the first 6 should be listed followed by 'et al.' For further details you are referred to 'Uniform Requirements for Manuscripts submitted to Biomedical Journals' (J Am Med Assoc 1997; 277:927-34)(see also Samples of Formatted References).

Journal names should be abbreviated according to the List of Title Word Abbreviations.

Elsevier accepts video material and animation sequences to support and enhance your scientific research. Authors who have video or animation files that they wish to submit with their article are strongly encouraged to include links to these within the body of the article. This can be done in the same way as a figure or table by referring to the video or animation content and noting in the body text where it should be placed. All submitted files should be properly labeled so that they directly relate to the video file's content. In order to ensure that your video or animation material is directly usable, please provide the file in one of our recommended file formats with a preferred maximum size of 150 MB per file, 1 GB in total. Video and animation files supplied will be published online in the electronic version of your article in Elsevier Web products, including ScienceDirect. Please supply 'stills' with your files: you can choose any frame from the video or animation or make a separate image. These will be used instead of standard icons and will personalize the link to your video data. For more detailed instructions please visit our video instruction pages. Note: since video and animation cannot be embedded in the print version of the journal, please provide text for both the electronic and the print version for the portions of the article that refer to this content.

Supplementary material such as applications, images and sound clips, can be published with your article to enhance it. Submitted supplementary items are published exactly as they are received (Excel or PowerPoint files will appear as such online). Please submit your material together with the article and supply a concise, descriptive caption for each supplementary file. If you wish to make changes to supplementary material during any stage of the process, please make sure to provide an updated file. Do not annotate any corrections on a previous version. Please switch off the 'Track Changes' option in Microsoft Office files as these will appear in the published version.

One set of page proofs (as PDF files) will be sent by e-mail to the corresponding author (if we do not have an e-mail address then paper proofs will be sent by post) or a link will be provided in the e-mail so that authors can download the files themselves. To ensure a fast publication process of the article, we kindly ask authors to provide us with their proof corrections within two days. Elsevier now provides authors with PDF proofs which can be annotated; for this you will need to download the free Adobe Reader, version 9 (or higher). Instructions on how to annotate PDF files will accompany the proofs (also given online). The exact system requirements are given at the Adobe site.

If you do not wish to use the PDF annotations function, you may list the corrections (including replies to the Query Form) and return them to Elsevier in an e-mail. Please list your corrections quoting line number. If, for any reason, this is not possible, then mark the corrections and any other comments (including replies to the Query Form) on a printout of your proof and scan the pages and return via e-mail. Please use this proof only for checking the typesetting, editing, completeness and correctness of the text, tables and figures. Significant changes to the article as accepted for publication will only be considered at this stage with permission from the Editor. We will do everything possible to get your article published quickly and accurately. It is important to ensure that all corrections are sent back to us in one communication: please check carefully before replying, as inclusion of any subsequent corrections cannot be guaranteed. Proofreading is solely your responsibility.

The corresponding author will, at no cost, receive a customized Share Link providing 50 days free access to the final published version of the article on ScienceDirect. The Share Link can be used for sharing the article via any communication channel, including email and social media. For an extra charge, paper offprints can be ordered via the offprint order form which is sent once the article is accepted for publication. Corresponding authors who have published their article gold open access do not receive a Share Link as their final published version of the article is available open access on ScienceDirect and can be shared through the article DOI link.

Visit the Elsevier Support Center to find the answers you need.  Here you will find everything from Frequently Asked Questions to ways to get in touch.

You can also check the status of your submitted article or find out when your accepted article will be published.