ISSN 0870-7103
[printed version]

INSTRUCTIONS FOR AUTHORS

• Scope and policy
• Editorial Policy
• Scientific organisation of articles
• Formal layout of articles
• Submission of articles for editorial consideration
• Editorial procedure
• Assignment of copyright
• References
• Annexes

The Portuguese Journal of General Practice (RPCG) accepts for publication articles on basic epidemiological and clinical research in epidemiology, on the administration of health services and education, review articles, articles on clinical practice, case reports, opinion articles and any others that may contribute to the development of the speciality of general family medicine or the improvement of primary health care. Articles can be written in Portuguese, English or Spanish.

This document sets out the latest version of the instruction for submitting articles to the RPCG (hereinafter called ‘Instructions’). It is a revision and updating of the instructions published in 2009.¹ Citations of this version should use this reference: Conselho Editorial da RPCG. Instructions for the submission of articles to the Portuguese Journal of General Practice. Rev Port Clin Geral 2010;26:325-40. This document is not protected by copyright and it may be copied, reprinted and distributed electronically without permission.

Authors are recommended to use the electronic version of the annexes and forms included in these instructions when they want to submit a manuscript. They are available on the RPCG website.

Authorship

The production of a scientific work is the outcome of the contributions of a number of people and bodies. But not all contributions credit authorship of the work.

Persons credited as authors must meet the three requirements of the International Committee of Medical Journal Editors for the definition of authorship, and everyone who meets these requirements must be named as authors:

• They must have contributed substantially to the conception and design, acquisition of data, or analysis and interpretation of data;
• They must have participated in drafting the article or its critical revision for intellectually important content;
• They must have revised the final version of the manuscript and approved it for publication.

Other persons who may have contributed to the work but who do not fulfil the criteria for authorship should be mentioned in the Acknowledgments. Individuals or bodies who only contribution has involved the funding of the work are not included here.

Conflict of interests

There is a conflict of interests when an author (or their institution) has personal or financial relationships that can influence their decisions, work or manuscript. Not all such relationships amount to real conflicts of interests. On the other hand, the potential for conflict of interest can exist regardless of whether an individual believes that the relationship affects his or her scientific judgment. The potential for conflict of interests can lie with authors, reviewers or editors.

To maintain transparency in the process, therefore, all parties involved in the publication of articles (authors, reviewers and editors) are asked to declare any potential conflict of interests. But their existence is not necessarily grounds for the RPCG to reject a manuscript.

If the work has been funded wholly or partially by one or more individual or body, this information must be published along with the article. The existence of external funding is not a criterion for either accepting or rejecting manuscripts.

Ethical conduct

Research work on human subjects is only considered valid if the authors have followed ethical standards in accordance with the concepts established in the Helsinki Declaration. The research protocol must have been submitted to an independent ethical committee regardless of whether it has pronounced in favour (or not) of it. The approval of this committee must be included in the documents delivered when submitting the article (together with Annex V). In the absence of a submission by the ethics committee, the author responsible for correspondence with the RPCG shall prepare a statement of ethical conduct, setting out the reason why the submission was not made and assuming compliance with the ethical principles relating to those studies. If any of these documents is missing the manuscript will not be accepted for assessment by the Editorial Board.

All articles submitted for publication in the RPCG must be prepared in accordance with the Uniform Requirements for Manuscripts Submitted to Medical Journals, drawn up by the International Committee of Medical Journal Editors^2,3 and the documents in the EQUATOR (Enhancing the Quality and Transparency of Health Research) network.⁴

The journal publishes articles on the initiative of authors and editors. Articles on the initiative of authors are: original research, reviews, case reports, articles on practice, opinion and discussion articles, short articles and letters to the editors. Editorials, documents, Dossier articles, POEMs, Journal Club and texts for Web Health are on the initiative of the editors, although submissions from authors may be accepted provided that they first contact the editors of the RPCG. Author-initiated articles and those requested by editors are subject to peer review.

This section sets out the items common to all articles and a description of their various types.

Items common to all types of article

All articles submitted to the RPCG must have a Title, a description of the Authors, a body of text and References. Most kinds require an Abstract. If certain individuals have made important contributions to the article but do not fulfil the criteria of authorship, an Acknowledgements section can be included between the main text and the references. Illustrations can be included in the main text, in some kinds of articles. The information on conflicts of interests and the funding of the work should come after the references.

The Title and Abstract should be in Portuguese and English.  When the article is published in Portuguese, the first abstract will be in Portuguese and the second in English. If the article is in English, the order is reversed. If the article is in Castilian the first abstract (Resumen) will be in that language, followed by an abstract in Portuguese and the English version will come at the end of the article. Abstracts must not exceed 300 words and must be followed by two to six keywords. The keywords must be terms from the MeSH list of medical descriptors,⁵ the BIREME health sciences descriptors (DeCS)⁶ or those listed in the PORBASE subject index.⁷ The structure of the abstract for each type of article is explained in the respective section.

Two kinds of illustration are allowed: figures and tables. The figures must be numbered with Arabic numerals and the tables with Roman numerals, in the order of their first mention in the text. The text should not repeat information contained in illustrations, but should confine itself to summarising the most important aspects. The number of illustrations allowed for each type of article is explained in the respective section.

The References must follow the international rules (Vancouver style).⁸

Original research

Content: These are research articles in the area of general family medicine or primary health care. They must follow the internationally accepted rules for articles of this nature.^2,3 Authors are encouraged to follow STROBE⁹for observational studies, CONSORT¹⁰ for clinical trials, the STARD rules¹¹ for diagnostic accuracy studies, the COREQ rules¹² for qualitative studies, the SQUIRE guidelines¹³ for quality assurance and improvement studies.

Size: They should not exceed 8000 words, and no more than 10 illustrations (figures or tables) are permitted per article.

Structure: There must be a Title, Abstract and two to six Keywords in each of the required languages (see above). The body of the article must contain the following sections: Introduction, Methods, Results and Discussion. An Acknowledgments section can also be included. The article must contain References.

Main text: The Introduction must be concise. It must clearly state the problem, summarise the current state of knowledge on the topic and explain why the study has been carried out. The objectives and/or theories formulated must be stated at the end of the introduction. The Methods should describe the set-up, place and duration of the study, the population studied, sampling methods, observation units and variables measured, data acquisition methods, criteria, instruments, and techniques and apparatus used. The statistical methodology must be stated. The Results should be set out clearly, using text and illustrations (figures or tables). The Discussion must focus on new or important aspects of the study and present only those conclusions that are justified by the results. Comparisons must be drawn with identical studies undertaken by other authors and any limitations or biases with a bearing on the study should be explained. New working hypotheses can be suggested. Only assertions based on the study conducted can be made, and there must be no allusions to incomplete or unpublished works. The study’s conclusions must be given in the closing paragraphs of the discussion.

Case report

Content: These are descriptions of clinical cases that help to improve decision-taking in diagnostic or therapeutic investigation and which include aspects related to education or health policies.

Size: They should not exceed 6000 words, and no more than eight illustrations (figures or tables) are permitted per article.

Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). The body of the article must contain the following sections: Introduction, Case description and Comment. An Acknowledgments section can also be included. The article must contain References.

Main text: The Introduction should explain why the clinical case is being submitted in a concise manner and without making a theoretical review of the problem in question. The Case description must comprise an actual clinical history, set out in a structured manner, using subheadings if necessary. The Comment should draw attention to relevant practical aspects, problems encountered in clinical practice or lessons to be learned from the case report.

Review

Content: These articles consist of literature reviews, synthetic studies or clinical updates that may be supplementary instruments to update and improve clinical practice. Authors are encouraged to follow the PRISMA rules for systematic reviews,¹⁴ MOOSE for meta-analyses of observational studies¹⁵ and the recommendations of Riley et al for meta-analyses of individual patient data.¹⁶ The authors of evidence-based review articles may find the recommendations published in the journal American Family Physician useful.¹⁷

Size: Review articles should not exceed 8000 words, and no more than 10 illustrations (figures or tables) are permitted per article.

Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). The body of the article must contain the following sections: Introduction, Methods, Results and Conclusions. An Acknowledgments section can also be included. The article must contain References.

Main text: The Introduction must be concise. It must clearly set out the problem to be tackled, state the reasons for carrying out the study and discuss its timeliness The question and the specific purpose of the review should be clearly stated at the end of the introduction. The Methods must describe the methodology employed in preparing the review. Specific mention must be made of the topic under review, various definitions (e.g. diagnostic criteria), method used for the literature search (period covered by the review, electronic and/or documental databases consulted, descriptors used for the search, manual search of bibliographies, contact with experts in the area to identify relevant articles) and procedures and criteria for selecting the articles. The presentation of the Results must be structured and systematised, using subheadings, if necessary. This section must contain the results of the search and a critical discussion (assessment of data quality, synthesis of data, comparison of opinions, identification of unresolved issues).   The Conclusions must provide a critical summary of the relevant data, stress the practical facets, stating the remaining problems and suggest future prospects.

Practice

Content: These are quality assessment reports or works describing experiences or projects regarded as relevant to improving the quality of care provided to patients in primary health care.

Size: They should not exceed 5000 words, and no more than four illustrations (tables or figures) are permitted per article.

Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). There is no specific structure for the main text. An Acknowledgments section can also be included. The article must contain References.

Training

Content: Project reports and articles on experiences considered important in the sphere of pre- and post-graduate medical education in the context of primary health care.
Size: They should not exceed 5000 words, and no more than six illustrations (tables or figures) are permitted per article.
Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). There is no specific structure for the main text. An Acknowledgments section can also be included. The article must contain References.

Opinion and Discussion

Content: Free opinion articles likely to stimulate reflection and discussion on topics of interest to general family medicine.

Size: They should not exceed 4000 words, and no more than six illustrations (tables or figures) are permitted per article.

Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). There is no specific structure for the main text. An Acknowledgments section can also be included. The article must contain References.

Short Article

Content: Brief articles such as short original studies or the publication of preliminary results, clinical case notes or small series studies.

Size: They should not exceed 3000 words, and no more than four illustrations (tables or figures) are permitted per article.

Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). There is no specific structure for the main text. An Acknowledgments section can also be included. The article must contain References.

Letter to the Editor

Content: This consists of comments on articles published previously in the journal or short notes on experiences pertinent to daily practice. Letters referring to articles will only be accepted within three months of publication of the original article.

Size: They should not exceed 750 words, and only one illustration (figure or table) and up to 5 references are permitted per article.

Structure: There is no specific structure. The article may contain References.

Editorial

On the initiative of the Editorial Board. It must contain no more than 1200 words and there is a limit of 15 references. Up to 2 illustrations (tables or figures) are accepted.

Documents

Content: These consist of statements, recommendations or other documents of national or international scope of relevance to general family medicine.

Dossier

Content: The Dossier contains articles on a common topic. The purpose of the dossier is to publish up-to-date scientific papers and review articles by experts. Articles for the dossier are selected by the editors of the RPCG or by an expert appointed by the Editorial Board as a coordinating member.

Size: Dossier articles should not exceed 6000 words, and no more than 8 illustrations (tables or figures) are permitted per article.

Structure: Articles must contain a Title, Abstract and two to six Keywords in each of the required languages (see above). There is no specific structure for the main text. An Acknowledgments section can also be included. The article must contain References.

POEM

Content: This section relates to POEMs (Patient-Oriented Evidence that Matters), to which a level of evidence is assigned according to the Oxford Centre for Evidence Based Medicine.¹⁸ The concepts related to POEMs have already been widely reviewed.^19,20

Size: Comments should not exceed 1000 words. No illustrations are allowed.

Journal Club

Content: The purpose of this section is to provide an annotated reading of articles, books or other texts from other scientific publications. The article or publication chosen must be current (published in the past 3 months) and relevant to the clinical practice of general family medicine.

Size: Articles should not exceed 1300 words. No illustrations are allowed.

Web Health

Content: The purpose is to publicise Internet sites relevant to general family medicine. Resources are available to help with the critical appraisal of the health information provided on the Internet.²¹Size: Comments should not exceed 350 words. One illustration per Internet site referenced is allowed, up to a limit of 3 illustrations per text.

Structure: A Title and References to the site should be included. The main text should include information on the resources provided on the site, name the body responsible for the content and there must be a description of how the author uses the site in their general family medicine practice. The title in the other required languages (see above) will only be published in the online version of the RPCG.

In brief

Type of article	Abstract structure	Main text structure	Size (words)	Illustrations
Original research	Objectives, type of study, place, population, methods, results and conclusions	Title*, Abstract*, Keywords*, Introduction, Methods, Results, Discussion, [Acknowledgments] and References	8000	≤10
Case report	Introduction, Case description and Comment	Title*, Abstract*, Keywords*, Introduction, Case description, Comments, [Acknowledgments] and References	6000	≤8
Review	Objectives, Data sources, Review methods, Results and Conclusions	Title*, Abstract*, Keywords*, Introduction, Methods, Results, Conclusion, [Acknowledgments] and References	8000	≤10
Practice	There is no mandatory structure	Title*, Abstract*, Keywords*, [main text], [Acknowledgments] and References	5000	≤4
Training	There is no mandatory structure	Title*, Abstract*, Keywords*, [main text], [Acknowledgments] and References	5000	≤6
Opinion and discussion	There is no mandatory structure	Title*, Abstract*, Keywords*, [main text], [Acknowledgments] and References	4000	≤4
Short article	There is no mandatory structure	Title*, Abstract*, Keywords*, [main text], [Acknowledgments] and References	3000	≤4
Letter to the editor	No abstract	[main text]	750	≤1
Editorial	No abstract	[main text]	1200	≤2
Dossier	There is no mandatory structure	Title*, Abstract*, Keywords*, [main text], [Acknowledgments] and References	6000	≤8
POEM	No abstract	Title*, References, Clinical question, Summary of study, Comments	1000	0
Journal Club	No abstract	Title*, Citation [main text structured like original article], Comments, References	1300	0
Web Health	No abstract	Title*, References, [main text] Comments	350	≤3

*Items required for all types of article (see “Items common to all types of article”).

Format of electronic files

Articles should be typed on any word processor and recorded in one of the following formats: Microsoft Word, RTF or Open Office. Pages must be numbered.

First page
This should only contain:

1. The title of the article, which must be concise.
2. The name(s) of the author(s) (only two or three names per author).
3. The degree, professional and/or academic title or titles or the author(s).
4. The department or institution where the author(s) works/work.

Second page
This should only contain:

1. The name, phone/fax number/email address and postal address of the author corresponding with the journal vis-à-vis the manuscript.
2. The name, email address and postal address of the author to whom correspondence on the article should be addressed after publication.

Third page
This should only contain:

1. Title of the article in the required languages.
2. Abstract of the article in the required languages. The abstract must obey the instructions specified for the type of article in question. It must allow understanding of the article without the need for reading it.
3. From two to six keywords in the required languages using terms from the MeSH  list of medical descriptors,⁵ from the BIREME health sciences descriptors (DeCS)⁶ or those listed in the PORBASE subject index.⁷
4. Indication of the article typology (section of the journal for which it is intended).

Next pages

These will contain the text of the article, with each section into which it is subdivided starting on a new page.

First page after article text

An Acknowledgments section should be included, if appropriate.

First page after Acknowledgments

The References section should start here.

First page after References

Next pages

These should contain the illustrations. Each must be on a separate page, and numbered (Arabic or Roman numerals), with caption. Tables should use Roman numerals and must have a short title. Explanatory footnotes may be added, if necessary, and marked using the symbols listed in the Vancouver style guidelines.^2,3 Graphics, diagrams, prints and photographs (figures) must be submitted in good enough quality for them to be reproduced directly. Arabic numerals must be used. Three-dimensional graphics are not allowed. Figures in digital format must be sent as separate files and not included in the text of the document. JPEG, TIF and EPS formats are accepted, and resolution should be 300 dpi or better. Figures on paper or film (slides) must be of high quality and be duly identified (Arabic numerals) with a self-adhesive label on the back or in the margin. Digital format images are preferred since their quality will not be compromised. The Vancouver style guidelines^2,3 must be applied to the use of photographs of people or photographs that have already been published.

Style rules

Abbreviations, symbols and units of measurement must follow internationally accepted rules.^2,3

1. Uppercase is used only as indicated below:
1. in the title and main sections of the work;
2. at the beginning of a subtitle (if any);
3. for the first word of all sentences;
4. for the main words of chapters, sub-chapters, sections and subsections;
5. in titles of figures and tables;
6. in names of scales and instruments of measurement;
7. in nouns determined by a numeral or letter, and
8. in names of academic courses and subjects.
2. Always use the pharmacological name. The trade name can be added in brackets after the first reference to the drug in the text, if justified.
3. Figures below ten should be written in words. Exceptions are: if comparisons are being drawn with figures of 10 or higher, if units of measurement are being used, to represent mathematical functions, fractions, percentages and ratios. Never start a sentence with a figure.
4. Always use figures to denote time, date, age, sample and population, size, results, dosage, percentages, temperature degrees, metric measurements and points on a scale.
5. As a rule, avoid the use of abbreviations outside brackets. The exception is those used for measurement systems (e.g. kg).
6. Acronyms should only be used if they are part of everyday language (e.g. WHO) or to denote an abbreviation or technical expression used repeatedly (e.g. COPD). In these circumstances it should appear in brackets after the original expression on the first occasion of its use in the text.
7. Foreign words and phrases should be avoided, as far as possible.
8. No underscoring.
9. Only use bold in titles.
10. Italics should be used only as indicated below: in literature references, foreign words and technical names of scientific classes.
11. Statistical symbols (e.g. t, r, M, DP, p) should be written in italics, apart from Greek symbols.
12. A comma, not a point, is used as decimal separator.
13. In the text, decimal numbers should only be given to two places and rounded, except in duly grounded exceptional instances.
14. There should be a space before and after arithmetical and logical operators,  like +, -, =, <, and >.

References

Literature references should be noted in the text with subscript Arabic numbers in order from the first citation and included in this chapter, with exactly the same citation order being used in the text. Names of journals must be abbreviated according to the style used in the Index Medicus. The Portuguese Journal of General Practice is referenced as Rev Port Clin Geral. The reference number must be place after the punctuation (full stop, comma, etc.).

Examples:

(...) as is the case of distribution lists.⁵

More recent studies by Di-Franza and colleagues,⁷show that children become addicted to nicotine more easily than adults.

If more than one reference has to be cited after a phrase, their numbers must be separated by commas, unless they are sequential, when they are separated by a hyphen.
Examples:

References to legal documents must be concise but complete, and give information on the kind of law and its number and date, where it was published and pages.

Example:

Documents should be sent by email to: secretariado@rpcg.apmcg.pt. If the files are too large to send by email they should be sent by CD-ROM or some other physical form, to: Director da Portuguese Journal of General Practice, Av. da República, 97-1º 1050-190 Lisboa.
The documents should include:

• The original of the article, with illustrations, recorded on CD-ROM or in file(s) attached to the email message in Microsoft Word, RTF or Open Office format (text, tables and diagrams) and JPEG, TIF or EPS (illustrations).
• The form in Annex 1, completed by each author. In addition to the electronic format version, the original of the document must be sent by ordinary mail.
• The form in Annex 2, completed by the corresponding author.
• An authorised declaration signed by each person mentioned in the Acknowledgments (Annex 3).
• For an original study, the ethical conduct statement (Annex 4), completed by the corresponding author.
• For case reports, statement of informed consent signed by the patient motivating the case report (Annex 5).
• If there is a photograph of the patient(s), informed consent statement signed by the patient photographed (Annex 5).
• Copies of any authorisations to reproduce material already published, to use figures or report sensitive personal information about identifiable individuals.
• Checklist, attached, duly completed (Annex 6).

Texts received are given a number which is communicated to the authors. This number must be referred to in all correspondence with the journal. Date of receipt of the article is held to be the date on which the electronic version is received, or the day on which the mailed version arrives, whichever is earlier.

Once the typology of the article is established the texts undergo administrative validation. Those that do not comply with the scientific organisation and formal layout set out in these instructions will not be sent to the Editorial Board. Articles are returned automatically. Manuscripts that meet the rules will be sent to an editor. This editor will make a brief assessment and submit the article at a meeting of the Editorial Board. Articles not related to the journal's mission (the development of the speciality of general family medicine or the improvement of primary health care) will be rejected.

Articles that comply with the rules and which are relevant to the mission of the journal will be sent for peer review. Reviewers will be asked for a critical assessment of articles submitted for publication. This assessment will cover the following: topicality, scientific reliability, clinical importance and interest in publishing the text. independence and impartiality of assessment are ensured by sending articles to reviewers without any identification of the authors, and each article will be assessed by two or more reviewers. If the opinions of the reviewers diverge, the editors can invite a third reviewer. The final decision on publication will be taken by the editors on the basis of the reviewers’ opinions. The various considerations of the reviewers will be summarised by the editor handling the article and the author(s) will be duly informed. The authors will not know the identity or affiliation of the reviewers or the editor in charge.

The publication decision may be a rejection, publication without any changes or publication after changes. This last category, of articles to be published after the proposed modifications have been made, will be reappraised by the original reviewers. The editor in charge will then make a final assessment and decide on rejection or publication without further changes. The authors of articles accepted for publication will be told the likely date of publication.

The authors will assign to the RPCG the sole right to publish and distribute the content of the manuscript specified in this declaration via physical, electronic, broadcasting or any other medium that may come into existence. They also grant the RPCG the right to use and exploit this manuscript, in particular by assigning, selling or licensing its content. This permission is permanent and takes effect from the moment the manuscript is submitted, has the maximum duration allowed by applicable Portuguese or international law and is of worldwide scope. The authors further declare that this assignment is made free of charge.  If the RPCG informs the authors that it is not going to publish their manuscript, the exclusive assignment of rights ceases forthwith.

The authors authorise the RPCG (or any entity it may appoint) to act on their behalf when it believes that copyright may have been infringed.

The authors are entitled to:

• Make a reasonable number of copies of their work in physical or digital medium for their personal and professional use and for teaching purposes, but not for any commercial purpose (including sale of the right of access to the article).
• Place an exact copy in electronic format of the article published by the RPCG on their website or that of their institution provided that due reference is made to its publication in the RPCG and its content (including symbols identifying the RPCG) has not been altered.
• Publish in a book of which they are the authors or editors the content of the manuscript in full or in part, provided there is due reference to its publication in the RPCG.
• Receive, for five years after publication, 10% of the amount paid to the RPCG by third parties for offprints of their article, if this amount exceeds EUR 1500.

1. Conselho Editorial da Revista Portuguesa de Clínica Geral. Normas para apresentação de artigos à Revista Portuguesa de Clínica Geral. Rev Port Clin Geral 2009; 25: 130-144.
2. Comissão Internacional de Editores de Revistas Médicas. Requisitos uniformes para manuscritos submetidos a revistas biomédicas: escrever e editar para publicação biomédica. Montenegro M, tradutor, Sousa JC, tradutor. Rev Port Clin Geral 2007;23:778-98.
3. International Committee of Medical Journal Editors [página na Internet]. Uniform Requirements for Manuscripts Submitted to Biomedical Journals: Writing and Editing for Biomedical Publication [acedido em 20/05/2010]. Disponível em: http://www.icmje.org
4. The EQUATOR Network. Enhancing the Quality and Transparency of Health Research [página na Internet]. Oxford: Minervation Ltd; [acedido em 20/05/2010]. Disponível em: http://www.equator-network.org/
5. US National Library Medicine. Medical Subject Headings[página na Internet]. Bethesda: National Library Medicine; [actualizado em 2008/12/18; acedido em 20/05/2010]. Disponível em: http://www.nlm.nih.gov/mesh/
6. BIREME. Descritores em ciências da saúde (DeCS) [página na Internet]. São Paulo:Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde; [acedido em 20/05/2010]. Disponível em: http://decs.bvs.br/
7. Biblioteca Nacional. Porbase - Base Nacional de Dados Bibiográficos [página na Internet]. Lisboa: Biblioteca Nacional; [actualizado em 27/06/2007; acedido em 20/05/2010]. Disponível em: http://www.porbase.org/projectos/terminologias-clip.html
8. Patrias, K. Citing medicine: the NLM style guide for authors, editors, and publishers [Internet]. 2nd ed. Wendling, DL, technical editor. Bethesda (MD): National Library of Medicine (US); 2007 [actualizado em 21/10/2009; acedido em 20/05/2010]. Disponível em: http://www.nlm.nih.gov/citingmedicine
9. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC,Vandenbroucke JP; STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol. 2008 Apr;61(4):344-9.
10. Schulz KF, Altman DG, Moher D, for the CONSORT Group. CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials. BMJ  2010;340: c332-c332
11. Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA,Glasziou PP,Irwig LM, Lijmer JG, Moher D, Rennie D, de Vet HCW, the STARD Group.Towards Complete and Accurate Reporting of Studies of Diagnostic Accuracy: The STARD Initiative. Clinical Chemistry 2003;49:1-6.
12. Tong A, Sainsbury P, Craig J. Consolidated criteria for reporting qualitative research (COREQ): a 32-item checklist for interviews and focus groups. Int J Qual Health Care 2007 Dec;19(6):349-57.
13. Davidoff F, Batalden P, Stevens D, Ogrinc G, Mooney S. Publication Guidelines for Quality Improvement Studies in Health Care: Evolution of the SQUIRE Project. J Gen Intern Med 2008 Oct 2.
14. Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. Clin Epidemiol 2009; 62(10):1006-12.
15. Stroup DF, Berlin JA, Morton SC, Olkin I,Williamson GD, Rennie D, Moher D, Becker BJ, Sipe TA,Thacker SB, the Meta-analysis Of Observational Studies in Epidemiology Group. Meta-analysis Of Observational Studies in Epidemiology: A proposal for reporting. JAMA 2000;283:2008-12.
16. Riley RD, Lambert PC, bo-Zaid G. Meta-analysis of individual participant data: rationale, conduct, and reporting. BMJ 2010;340:c221
17. Siwek J, Gourlay ML, Slawson DC, Shaughnessy AF. How to write an evidence-based clinical review article. Am Fam Physician. 2002 Jan 15;65(2):251-8.
18. Phillips B, Ball C, Sackett D, Badenoch D, Straus S, Haynes B, Dawes M, Howick J. Levels of Evidence [página na Internet]. Oxford: Centre for Evidence-based Medicine; [actualizado em Março 2009; acedido em 20/05/2010]. Disponível em: http://www.cebm.net/?o=1025
19. Sanchez JP. Simplesmente POEMs. Rev Port Clin Geral 2005 Nov-Dez; 21(6): 631-4.
20. Mateus M, Sanchez JP. POEMs: glossário e níveis de evidência. Rev Port Clin Geral 2006;22:400-4.
21. Charnock D, editor. The DISCERN handbook - Quality criteria for consumer health information on treatment choices. 1st Ed. Oxford: Raddcliffe Medical Press Ltd; 1998.