Author Guidelines

I. Type of Articles

We accept manuscripts in the following categories as detailed below: (i) Full Length Articles; (ii) Short Communications; (iii) View & Review; (iv) Clinical Research Design and (v) Letter to the Editor.

Full Length Articles

Full length articles are reports of original research on its overall size. Maximum length is 4000 words, not including abstract, figure legends, table legends and references. These articles require a structured abstract of 250 words at most. 40 references and 5 figures OR tables are allowed. Authors should cite only the best references, since multiple citations for a single point are usually duplicative, and avoid citing non-peer reviewed articles. Additional content may be submitted and published at the editor’s discretion.

Short Communications

Short Communications are abbreviated reports, which contain no more than 1250 words (excluding references), have no abstract, only 1 table or figure and 7 references or less.

View & Review 

View and review articles are a review or an opinion statement that constists on a summary of the most relevant information on a topic. They should not exceed 5000 words, excluding references and an abstract that is at most 250 words. References should cite the most important papers on the subject (not more than 60). Up to 6 figures are allowed. Principles and Practice of Clinical Research also accepts manuscripts proposing medical hypothesis. We also encourage submission of mini-review, that is a short review with up to 1500 words to discuss concisely a novel idea.

Clinical Research Design

We encourage and accept articles reporting the methodology of well-designed trials. This type of article should have no more than 3000 words, a structured abstract and only 1 table or figure and 25 references or less. For clinical research design manuscripts, authors should make clear in the manuscript the limitations and strengths of the chosen design.

Letter to the Editor

Letter to the editor consists on brief comments regarding aspects in response to specific published articles or also to report important preliminary data. They should have a maximum of 600 words, with no more than 5 references.

II. Ethics in publishing


Principles and Practice of Clinical Research adheres to the guidelines regarding authorship set by the International Committee of Medical Journal Editors. Authors must meet all of the following criteria: (1) contributing to the conception and design, or analyzing and interpreting data; (2) drafting the article or revising it critically for important intellectual content; and (3) approving the final version to be published. Supporting the study or collecting data does not constitute authorship. Authorship based solely on position (e.g., research supervisor, department head) is not permitted.


Plagiarism clearly occurs when large portions of text are cut-and-pasted (such manuscripts would not be accepted for publication) and will not be accepted.

Conflict of interest

All authors are requested to disclose any actual or potential conflict of interest including any financial, personal or other relationships with other people or organizations within three years of beginning the submitted work that could inappropriately influence, or be perceived to influence, their work. Please download the COI form from ICMJE (link: Each author should fill out the form and all the forms need to be submitted together in a single PDF document.

III. Submission

Please review the editorial policies here before submission:

Editorial Policy

Authorship Guidelines

Peer-Review Policy

Conflict of Interest Policy

Human & Animal Rights Policy

Informed Consent Policy

Privacy Statement

IV. Structure of the paper

1. Title page

a) Title

Concise and informative. Avoid abbreviations and formulae whenever possible.

b) Author names and affiliations.

Present the authors' affiliation institutions (where the actual work was done) below the names and indicate all affiliations with a lower-case superscript number immediately after the author's name and in front of the appropriate institution. Provide the city and country of each affiliation.

c) Corresponding author

Clearly indicate who will handle correspondence at all stages of refereeing and publication, also post-publication. Ensure that email address is provided in addition to the complete postal address of the institution. Contact details must be kept up to date by the corresponding author.

2. Abstract

The abstract should state concisely the purpose of the research, the principal results and major conclusions. An abstract is often presented separately from the article, so it must be able to stand alone. Authors should avoid references, citing name(s) and year(s) only when essential. Also, non-standard or uncommon abbreviations should be avoided, but if necessary they must be defined at their first mention in the abstract itself.

3. Keywords

Immediately after the abstract, provide 6 keywords or less, which will be used for indexing purposes. Authors should use American spelling and avoid general and plural terms and multiple concepts (avoid, for example, 'and', 'of'). Be moderate with abbreviations: only abbreviations firmly established in the field are eligible.

4. Abbreviations

Define abbreviations that are not standard in this field in a footnote to be placed on the first page of the article. Ensure that there is a consistent pattern of abbreviations throughout the article. Superscript Arabic numerals are used for such footnotes.

5. Introduction

Present the objectives of the paper and state an adequate background, avoiding a detailed literature survey or a summary of the results.

6. Material and methods

Provide sufficient detail to allow the work to be reproduced. Methods already published should be indicated by a reference: only relevant modifications should be described.

7. Results

Results should be clear and concise.

8. Discussion

The discussion does not repeat the results of the work, but explores its significance. Frequently, a combined Results and Discussion section is appropriate. Avoid extensive citations and discussion of published literature.

9. Conclusions

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

10. Appendices

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.

11. References

We use the reference format of APA 7h - please see tutorial from APA: Authors should cite only papers directly related to the article, avoiding exhaustive lists. APA guidelines for referencing are explained below:
- In the text, the references should appear as the first author last name followed by the date of publication. Examples: 'as determined (Doe, 2010a, 2010b; Smith and Johnson, 2015). Smith et al. (2010) have shown …'

- In the reference list, references should be organized alphabetically using the surname of first author.

- Reference should be organized as: Brunoni AR, Valiengo L, Baccaro A, Zanão TA, de Oliveira JF, Goulart A, Boggio PS, Lotufo PA, Benseñor IM, Fregni F (2013). The sertraline vs. electrical current therapy for treating depression clinical study: results from a factorial, randomized, controlled trial. JAMA Psychiatry, 70, 383-91.

Authors are welcome and encourage to use a reference management software including EndNote, Mendeley, Zotero, or any other that allows to export formatted references to the word document. All of them have the APA 7th reference style option. If you have problems with any reference management software, please contact the source company's technical support.

12. Acknowledgements

This section cannot be included on the title page, as a footnote to the title or otherwise. In a separate section at the end of the paper, before the references, authors should list the individuals who provided help during the research.

13. Publication Language

As Principles and Practice of Clinical Research is an international journal, the official language is English. Authors who are not native English speakers are advised to seek help from native speakers or submit their work for professional copyediting before submission. There are several professional companies that offer these services. One that is recommended is A manuscript that is poorly written may not be accepted or authors may be asked to seek professional help.

V. Copyrights

Principles and Practice of Clinical Research journal do not require authors to transfer copyrights; however, we use the creative commons license (Creative Commons Attribution - CC BY) in articles published in the journal. This license lets others distribute, remix, adapt, and build upon your work, even commercially, as long as they credit you for the original creation. Please go to to check for more details.

VIII. Plagiarism check

The PPCRJ assesses plagiarism of all submitted manuscripts using Ithenticate system at the initial submission, revision process, and before the online publication. In case the editorial team identifies plagiarism the Editor-in-chief will contact the corresponding author to evaluate each case individually.

VII. Editorial Checklists

To facilitate the editorial work, we encourage the authors to use the following checklist before any submission (initial submission or revision). Also, the marked checklist must be uploaded on the platform at the initial submission.

+ Initial submission:

  • Cover letter: is there a cover letter stating work is original and made by the authors?
  • Is the manuscript following the format stated in the author's center menu (link)?
  • Author section: are the given name and last name per author clearly identified?
  • Corresponding author: are you providing the name, affiliation, and email of the corresponding author?
  • Are tables and figures in a separate document?
  • Figure format: TIFF with dpi 300 resolution
  • Are the references in APA 7th style?
  • Are conflicts of interest form per author ( attached?

    Please, attach the checklist marked during the initial submission. Download it here

+ Revision process:

  • Response letter: answering every comment of the reviewer
  • The marked version of the new manuscript/tables/figures
  • The clean version of the new manuscript/tables/figures

VII. Special Issues

The PPCR Journal editorial team will decide to release a special issue on a topic that is particularly current or to coincide with an important event or conference.

The editorial team can invite guest editors and commission papers from colleagues in the field or the team may choose to put out a call for papers (as an announcement on the website and social media). In this call for papers announcement, we will detail the requirements for submission (deadline, topics, publication type, etc.)

Notes for Authors

  • The submitted papers for a special issue will pass for all the rigorous editorial steps as for normal submission (submission checklist, double-blind peer review). Therefore, being invited to contribute a paper to a special issue is not a guarantee of publication.
  • Read journal policies, author guidelines, and call for papers announcement carefully, ensuring the manuscript meets all requirements before submission.
  • Indicate "This article is for the special issue …..." in cover letter when submitting.
  • Submit the manuscript by the deadline. Overdue submissions may be excluded from the special issue and processed as regular submissions.
  • Submit the manuscript via the Online Submission System.

If you are an author, you can click here to make a submission.
Take the above guidelines into account before making a submission.