ISSN 1870-199X
printed version







International Committee of Medical Journals Editors

A small group of editors of general medical journals met informally in Vancouver, British Columbia, in 1978 to establish guidelines for the format of manuscripts submitted to their journals. The group became known as the Vancouver Group. Its requirements for the manuscripts, including formats for bibliographic references developed by the National Library of Medicine, were first published in 1979. The Vancouver Group expanded and evolved into the International Committee of Medical Journal Editors (ICMJE), which meets annually; gradually it has broadened its concerns.

The committee has produced multiple editions of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals.

Over the years, issues have arisen that go beyond manuscript preparation. Some of these issues are now covered in the Uniform Requirements; others are addressed in separate statements.

The entire Uniform Requirements document was revised in 1997.Sections were updated in May 1999 and May 2000. A major revision is scheduled for 2001. The total content of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals may be reproduced for educational, nonprofit purposes without regard for copyright; the committee encourages distribution of the material.

Journals that agree to use the Uniform Requirements (over 500 do so) are asked to cite a version published in 1997 or later in their instructions to authors. It is important to emphasize what these requirements do and do not imply.

First, the Uniform Requirements are instructions to authors on how to prepare manuscripts, not to editors on publication style. (Many journals have drawn on them for elements of their publication styles.)

Second, if authors prepared their manuscripts in the style specified in these requirements, editors of the participating journals will not return the manuscripts for changes in style before considering them for publication. In the publishing process, however, the journals may alter accepted manuscripts to conform with details of their publication style.

Third, authors sending manuscripts to a participating journal should not try to prepare them in accordance with the publication style of that journal but should follow the Uniform Requirements.

Authors must also follow the instructions to authors in the journal as to what topics are suitable for the journal and the types of papers to be submitted- for example, original articles, reviews, or case reports. In addition, the journal's instructions are likely to contain other requirements unique to that journal, such as the number of copies of a manuscript that are required, acceptable languages, length or articles, and approved abbreviations.

A Scientific article is a manuscript that has been written in such a way that a competent and sufficiently qualified researcher, in the same field of expertise, and based solely on the indications in the article, could:

1. Reproduce the experiments and obtain the described results with a similar or smaller margin of errors than those described by the author.
2. Repeat the observations and judge the conclusions set out by the author.
3. Verify the exactitude of the analysis and deductions that were used by the author to reach his/her conclusions.

A review article is a manuscript whose primary aim is to summarize, analyze and discuss published works which relate to only one topic.

Short communications are manuscripts that present observations and brief scientific descriptions, in which the methodology and results are described, but in which the introduction and discussion are presented in a succinct way with the sole aim of placing the study within its scientific context.

Participating journals are expected to state in their instructions to authors that their requirements are in accordance with the uniform Requirements for Manuscripts Submitted to Biomedical Journals and to cite a published version.



Redundant or duplicate publication

Redundant or duplicate publication is publication of a paper that overlaps substantially with one already published.

Readers of primary source periodicals deserve to be able to trust that what they are reading is original unless there is a clear statement that the article is being republished by the choice of the author and editor. The bases of this position are international copyright laws, ethical conduct, and cost-effective use of resources.

Most journals do not wish to receive papers on work that has already been reported in large part in a published article or is contained in another paper that has been submitted or accepted for publication elsewhere, in print or electronic media. This policy does not preclude the journal considering a paper that has been rejected by another journal, or a complete report that follows publication of a preliminary report, such as abstract or poster displayed for colleagues at a professional meeting. Nor does it prevent journals considering a paper that has been presented at a scientific meeting but not published in full or that is being considered for publication in a proceedings or similar format. Press reports of scheduled meetings will not usually be regarded as breaches of this rule, but such reports should not be amplified by additional data or copies of tables and illustrations.

When submitting a paper, the author should always make a full statement to the editor about all submissions and previous reports that might be regarded as redundant or duplicate publication of the same or very similar work. The author should alert the editor if the work includes subjects about which a previous report has been published. Any such work should be referred to and referenced in the new paper. Copies of such material should be included with the submitted paper to help the editor decide how to handle the matter.

If redundant or duplicate publication is attempted or occurs without such notification, authors should expect editorial action to be taken. At the least, prompt rejection of the submitted manuscript should be expected. If the editor was not aware of the violations and the article has already been published, then a notice of redundant or duplicated publication will probably be published with or without the author's explanation or approval.

Preliminary reporting to public media, governmental agencies, or manufacturers, of scientific information described in a paper or a letter to the editor that has been accepted but not yet published violates the policies of many journals. Such reporting may be warranted when the paper or letter describes major therapeutic advances or public health hazards such as serious adverse effects of drugs, vaccines, other biological products, or medicinal devices, or reportable diseases. This reporting should not jeopardize publication, but should be discussed with and agreed upon by the editor in advance.

Acceptable secondary publication Secondary publication in the same or another language, especially in other countries, is justifiable, and can be beneficial, provided all of the following conditions are met.

1. The authors have received approval from the editors of both journals; the editors concerned with secondary publication must have a photocopy, reprint, or manuscript of the primary version.

2. The priority of the primary publication is respected by a publication interval of at least one week (unless specifically negotiated otherwise by both editors)

3. The paper for secondary publication is intended for a different group of readers; an abbreviated version could be sufficient.

4. The secondary version faithfully reflects the data and interpretations of the primary version.

5. The footnote on the title page of the secondary version informs readers, peers, and documenting agencies that the paper has been published in whole or in part and states the primary reference. A suitable footnote might read. "This article is based on a study first reported in the (title of journal, with full reference)"

Permission for such secondary publication should be free of charge.



Summary of technical requirements

1. Double space all parts of manuscripts.
2. Begin each section or component on a new page.
3. Review the sequence: title page, abstract and key words, text, acknowledgments, references, tables (each on separate page), legends.
4. Illustrations, unmounted prints, should be no larger than 203 x 254 mm (8x 10 inches).
5. Include permission to reproduce previously published material or to use illustrations that may identify human subjects.
6. Enclose transfer of copyright and other forms.
7. Submit required number of paper copies.
8. Keep copies of everything submitted.

Preparation of manuscript

The text of observational and experimental articles is usually (but not necessary) divided into sections with the headings Introduction, Methods, Results, and Discussion. Long articles may need subheadings within some sections (especially the Results and Discussion sections) to clarify their content. Other types of articles, such as case reports, reviews, and editorials, are likely to need other formats.

Authors should consult individual journals for further guidance.

Type or print out the manuscript on white bond paper, 216 x 279 mm (8.5 x 11 inches) or, ISO A4 (212 X 297mm) with margins of at least 25 mm (1 inch). Type or print on only side of the paper.

Use double spacing throughout, including for the title page, abstract, text, acknowledgments, references, individual tables, and legends.

Number pages consecutively, beginning with the title page. Put the page number in the upper or lower right-hand corner of each page.

1. The journal will only accept articles written in English and Spanish.

2. Authors must send the original and two printed copies, all double- spaced, and the respective computer disk.

3. Authors must number the pages in consecutive order.

4. Authors must number the lines on each page.

5. All articles must include the following:

a)Title of the article in Spanish
b) Complete name(s) of the author (s).
c) Institution which the authors(s) represents along with its complete address (at the foot of the first page)
d) Title of the article, in English, on a separate line.

6. The title must be as brief as possible, so long as it includes key words which permit one to quickly identify the nature and content of the article, even when it is published in references and bibliographic indexes. No abbreviations may be used in the text, or discretion must be used if this is indeed done.

7. The editorial committee reserves the right to select and publish those articles it deems worthy.

8. Articles contained within the journal are sole responsibility of the authors.

As the part of the edition process, after the final revision (English and Spanish) of the Journal, the article will be sent by E-mail to the author for its approval. The author will have to return it within 24 hours. If it is not received during this time, it will be considered as accepted for publication.

Manuscripts on Disk

For papers that are close to final acceptance, some journals require authors to provide a copy in electronic form (on a disk); they may accept a variety of processing formats or text (ASCII) files.

When submitting disks, authors should:

1. Be certain to include a print-out of the version of the article that is on the disk.
2. Put only the latest version of the manuscript on the disk.
3. Name the file clearly.
4. Label the disk with the format of the file and the file name
5. Provide information on the hardware and software used.

Authors should consult the journal's instructions to authors for acceptable formats, conventions for naming files, number of copies to be submitted and other details.

Requests that once the manuscript has been accepted and corrections have been carried out, authors must send an original and two printed copies, along with a 3.5 disk or CD, of the revised manuscript, as requested by the Editorial Committee in its second revision, the article on the disk must be in Microsoft Word. Furthermore illustrations must be sent in Excel, Power Point, Corel Draw (recent revision), both on the disk and on the printed versions. No transfer from different programs must be carried out.

When digitalizing images, secure a minimum of 600 pixels in BMP. TIF of CDR format must be used. No figures in JPG format will be accepted. Once the article has been definitively accepted, the English and Spanish versions must be included in one 305 disks or CD, in different files

Title Page (Initial)

The title page should carry a) the title of the article, which should be concise but informative; b) the name by which each author is known c) the name of the department(s) and institution(s) to which the work should be attributed request with regard to c) that the institution and department's complete addresses be included; as well as an indication, at the foot of the page, if the study is part of a thesis project); d) disclaimers, if any; e) the name and address of the author responsible for correspondence about the manuscript; f) the name and the address of the author to whom request for reprints should be addressed or a statement that reprints will not be available from the authors; g)source (s) of support in the form of grants, equipment, drugs, or all of these; and h)a short running head or foot line of no more than 40 characters (count letter & and spaces) at the foot of the title page. Request main author, responsible for correspondence, give his/ her full address, telephone number (including are codes, fax number and e- mail address.


Al persons designated as authors should qualify for authorship, and all those who qualify should be listed. Each author should have participated sufficiently in the work to take public responsibility for appropriate portions of the content. One or more authors should take responsibility for the integrity of the work as a whole, from inception to published article.

Authorship credit should be based only on a) substantial contributions to conception and design, or acquisition of data or analysis and interpretation of data; b) drafting the article revising it critically for important intellectual content ; and c) final approval of the version to be published. Conditions a), b), and c) must all be met. Acquisition of funding, the collection of data, of general supervision of the research group, by themselves, do not justify authorship.

Authors should provide a description of what each one of them or contributed, and editors should publish that information. All others who contributed to the work, who are not authors, should be named in the Acknowledgments, and what they did should be described.

The order of authorship on the byline should be joint decision of the coauthors. Authors should be prepared to explain in which order they are listed.

Editors may ask author to justify the order of authorship.

Request a letter signed by all the co- authors where they accept as authors in said manuscript.

Increasingly, authorship of multicenter trials is attributed to a group. All members of the group who are named as authors should fully meet the above criteria for authorship. Group members who do not meet these criteria should be listed, with their permission, in the Acknowledgments or in an appendix (see Acknowledgments).

The order of authorship should be a joint decision by all the co- authors. Given that the order can be assigned using different criteria, its significance cannot be inferred unless authors indicate the criteria used. Authors may wish to explain the order of authorship in a footnote. When deciding authors should take into account that many journals limit the number of authors that can be included in the contents, and that the National Library of Medicine only includes the first 40 authors and the last author, in MEDLINE, when there are more that 25 authors.

Abstract and Key Words

The second page should carry an abstract (of no more than 150 words for unstructured abstracts or 250 words for structured abstracts).

Below the abstract authors should provide, and identify as such, 3 to 10 key words or short phrases that will assist indexers in cross-indexing the article and may be published with the abstract. Terms from the Medical Subject Headings (MeSH) list of Index Medicus should be used; if suitable Me HS terms are not yet available, recently introduced terms may be used.

Note: A Spanish edition of MeSH elaborated by BIREME: "Descriptors of Health Sciences" [DeSC] can be consulted.


State the purpose of the article and summarize the rationale for the study observation. Give only strictly pertinent references and do not include data or conclusions from the work being reported.


Describe your selection of the observational subjects (laboratory animals, including controls) clearly. Identify the age, sex, and other important characteristics of the subjects. Because the relevance of such variables as age, sex and ethnicity to the object of research is not always clear, authors should explicitly justify them when they are included in a study report.

The guiding principle should be clarity about how and why a study was done in a particular way. For example, authors should explain why only subjects of certain ages were included or why others were excluded. Authors should avoid terms such as "race, " which lacks precise biological meaning, and use alternative descriptors such as "ethnicity" or "ethnic group " instead. Authors should specify carefully what the descriptors mean, and tell exactly how the data were collected (for example, what terms were used in survey forms, whether the data were self-reported or assigned by others, etc).

Identify the methods, apparatus (give the manufacturer's name and address in parentheses), and procedures in sufficient detail to allow other workers to reproduce the results.

Give references to established methods, including statistical methods (see below); provide references and brief descriptions for methods (have been published but are not well known; describe new or substantially modified methods, give reasons for using them, and evaluate their limitations. Identify precisely all drugs and chemicals used, including generic name(s) , dose(s), and route(s) of administration.

Reports of randomized clinical trials should present information on all major study elements, including the protocol (Study population, interventions or exposures, outcomes, and the rationale for statiscal analysis), assignment of interventions (methods of randomization, concealment of allocation to treatment groups), and the method of masking (blinding).

Authors submitting review manuscripts should include a section describing the methods used for locating, selecting, extracting, and synthesizing data. These methods should also be summarized in the abstract.


When reporting experiments on animals, indicate whether the institution's or national research council's guide, or any national law for, the care and use of laboratory animals was followed.


Describe statistical methods with methods with enough detail to enable a knowledgeable reader with access to the original data to verify the reported results. When possible, quantify findings and present them with appropriate indicators of measurement error or uncertainty (such as confidence intervals). Avoid relying solely on statistical hypothesis testing, such as the use of P values, which fails to convey important quantitative information. Discuss the eligibility of experimental subjects. Give details about randomization. Describe the methods for and success of ally blinding of observations. Report complications of treatment. Give numbers of observations. Report losses to observation (such as dropouts from clinical trial). References for the design of the study and statistical methods should be to standard works when possible (with pages stated) rather than to papers in which the designs or methods were originally reported. Specify any general- use computer programs used.

Put a general description of methods in the Methods section. When data are summarized in the Results section, specify the statistical methods used to analyze them. Restrict tables and figures to those needed to explain the argument of the paper and to assess its support. Use graphs as an alternative to tables with many entries; do not duplicate data in graphs and tables. Avoid nontechnical uses of technical terms in statistics, such as "random (which implies a randomizing device), "normal," "significant," correlations," and "sample." Define statistical terms, abbreviations, and most symbols.


Present your results in logical sequence in the text, tables, and illustrations. Do not repeat in the text all the data in the tables or illustrations; emphasize or summarize only important observations.


Emphasize the new and important aspects or the study and the conclusions that follow from them. Do not repeat in detail data or other material given in the Introduction or the Results section. Include in the Discussion section the implications of the findings and their limitations, including implications for future research. Relate the observations to other relevant studies.

Link the conclusions with the goals of the study but avoid unqualified statements and conclusions not completely supported by the data. In particular, authors should avoid making statements on economic benefits and costs unless their manuscript includes economic data and analyses. Avoid calming priority and alluding to work that has no been completed. State new hypotheses when warranted, but clearly label them as such. Recommendations, when appropriate, may be included.


List all contributors who do not meet the criteria for authorship, such as a person who provided purely technical help, writing assistance, or a department chair who provided only general support. Financial and material support should also be acknowledged.

Groups of persons who have contributed materially to the paper but whose contributions do not justify authorship may be listed under a heading to as "clinical investigators" or "participating investigators", and their function or contribution should be described, for example, "saved as scientific advisors," "critically reviewed the study proposal, "collected data,," or "provided and cared for study patients," Because readers may infer their endorsement of the data and conclusions, all persons must have given written permission to be acknowledged.


References should be numbered consecutively in the order in which they are first mentioned in the text. Identify references in text, tables, and legends by Arabic numerals in parentheses.

Use the style of the examples below, which are based on the formats used by the NLM in Index Medicus. The titles of journals should be abbreviated according to the style used in Index Medicus. Consult the List of Journals Indexed in Index Medicus, published annually as a separate publication by the library and as a list in the January issue on Index Medicus. The list can also be obtained on the internet, at:

Avoid using abstracts as references. References to papers accepted but not yet published should be designated as "in press" or "forthcoming"; authors should obtain written permission to cite such papers as well as verification that they have been accepted for publication. Information from manuscripts submitted but no accepted should be cited in the text as "unpublished observations" with written permission from the source.

Avoid citing a " personal communication" unless it provides essential information not available from a public source, in which case the name of the person and date of communication should be cited in parentheses in the text. For scientific articles, authors should obtain written permission and confirmation of accuracy from the source of a personal communication.

The references must be verified by the author (s) against the original documents. The Uniform style (the Vancouver style) is based largely on an ANSI standard Style adapted by the NLM for its data –bases. Notes have been added where Vancouver style differs from the style now used by NLM.

In those last names containing prepositions (von, van, di, de, de la, etc.) these must be cited before the last name; for example, Van Rensburg SN; De Buen Nuria; De la Torre, SF.

Include the last name and the initial of the first names of all the authors when these number six or less; in the case of more authors include only the first six and the add et al.

Articles in Journals

Standard journal article

(Note: NLM now list up through 25 authors; if there are more than 25 authors, NML list the first 24, then the last author, then et al.)

Vega K. J, Pina I, Krevsky B. Heart transplantation is associated with an increased risk for pancreatobiliary disease. Ann Intern Med 1996. Jun1;124 (11):980-983.

As an option, if a journal carries continuous pagination throughout a volume (as many medical journals do) the month and issue number may be omitted.

(Note: For consistency, the option is used throughout the examples in Uniform Requirements. NLM does not used the option.)

Vega KJ, Pina I Krevsky B Heart transplantation is associated with an increased risk for pancreatobiliary disease. Ann Intern Med 1996; 124 :980-983.

More than sis authors:

Parkin DM, Clayton D. Black RJ, Masuver E. Friedl HP, Ivarlov E, et al. Childhood leukaemia in Europe after Chernobyl: 5 year follow-up Br Cancer 1996;73:1006-1012.

Organization as author

The Cardiac Society of Australia and New Zealand. Clinical exercise stress testing. Safety and performance guidelines. Med J Aust 1996; 164: 282-284.

No author given

Cancer in South Africa [editorial]. S Afr Med J 1994; 84:15.

Article in another language different from English

Note: Articles must be written in their original language if they are in Latin type. The National Library of USA, and its Medline database, translate the title and puts it between square brackets, followed by the abbreviation of the original language. The original title of the article, when it is Latin type, can be visualized in the display option of "Display" selecting "Medline". Preceded figure of TT abbreviation.

Masilowski R, Jandl E, Krzyznski Z. [Reasons for culling of boards]. Russ. Spostrzezenia nt. Przyczyn brakowania knurow. Medycyna wet 1979; 35: 118-120.

Volume with supplement

Shen Hm, Zhang OF. Risk assessment of nickel carcinogenicity and occupational lung cancer; Environ Health Perspect 1994; 102 Suppl 1:275-282.

Issue with supplement

Payne DK, Sullivan MD, Massie MJ. Women's psychological reactions to breast cancer. Semin Oncol 1996;23 (1 suppl 2): 89-97.

Volume with part

Ozben T, Nacitarhan S Tuncer N Plasma an urine sialic acid in noninsulin dependent diabetes mellitus . Ann Clin Biochem 1995;32 (Pt3) 303-306.

Issue with part

Poole GH, Mills SM. One hundred consecutive cases of flap lacerations of the leg in ageing patients. N Z Med J 1994;107 (986 Pt 1) 377-378.

Issue with no volume

Turan I, Wredmark T, Fellander- Tsai L. Arthroscopic ankle arthrodesis in rheumatoid arthritis. Clin Orthop 1995; (320):110-114.

No issue or volume

Browell Da Lennard Tw. Immunologic status of the cancer patient and the effects of blood transfusion on antitumor responses. Curr Opion Gen Surg 1993: 325-333.

Pagination in Roman numerals

Fisher GA. Sikic BI. Drug resistance in clinical oncology and hematology, introduction . Hematol Oncol Clin North Am 1995 Apr; 9 (2) :xi-xii.

Indication of type of article as it corresponds

Rivas Otero B de, Solano Cebrián MC, López Cubrero L. Fiebre de origen desconocido y disección aórtica [carta]. Rev Clin Esp 2003; 203: 507-508.

Castillo Garzón MJ. Comunicación: medicina del pasado del presente y del futuro [editorial]. Rev Clin Esp 2004; 204 (4) :181-184.

Vázquez Rey L. Rodríguez Trigo G. Rodríguez Valcárcel ML, Verea Hernando H. Estudio funcional respiratorio en pacientes candidatos a trasplante hepático [resumen]. Arch Cronconeumol 2003;39 Supl 2:29-30.

Article with a retraction

Retraction of "Biotransformation of drugs by microbial of drugs by microbial cultures for predicting mammalian drug metabolism". Biotechnol Adv 2003 Mar; 21(1): 3-39.

Article with published erratum

Amlin JA, Kahn AM Herniography in symptomatic patients following inguinal hernia repair [published erratum appears inWest J Med 1995; 167:278]. West J Med 1995; 162:28-31.

Electronically published article before press version

Note: The CITES Epub ahead of print, are references sent to PubMed by editors of the journals which are published on-line as first instance, ahead of first edition. Afterwards, when a printed fromat is published, the reference is modified showing the printed edition data, followed by the electronic Epub. Sample of a reference in Pub Med published in electronic edition and when it is published in print.

Salt KH, Ashour A. Rajab M. Pregnancy outcome in non-gynecologic cancer. Arch Gynecol Obstet. 2004 Jun 2 [Epub ahead of print].

Sait KH, Ashour A, Rajab M. Pregnancy outcome in non-gynecologic cancer. Arch Gynecol Obstet. 2005 Apr; 271 (4): 346-349. Epub 2004 Jun 2.

Books and Other Monogrphs

Personal author(s)

Ringsven MK, Bond D. Gerodontology and leadership skills for nurses. 2nded. Albany (NY): Delmar Publishers, 1996.

Note: It is not necessary to mention first edition. The edition is always written in Arabic numbers and abbreviation: 2nd ed. If the piece of work has more than one volume, it should be cited after the book's title Vol 3.

Editor(s), compiler (s) as author.

Norman IJ Redfern SJ. Editors. Mental health care for elderly people. New York: Churchill Livingstone, 1996.

Organization as author and publisher

Institute of Medicine (US). Looking at the future of the Medicaid program. Washington: The institute, 1992.

Chapter in a book

(Note: Previous Vancouver style had a colon rather than a before pagination.)

Phillips SJ. Whisnant JP. Hypertension and stroke. In: Laragh JH, Brenner BM, editors. Hypertension: path physiology, diagnosis, and management. 2nd. New York: Raven Press, 1995: 465-478.

Conference proceedings

Kimura J, Shibasaki H, editors. Recent advances in clinical neurophysiology. Proceedings of the 10th International Congress of EMG and Clinical Neurophysiology; 1995 Oct 15-19; Kyoto, Japan. Amsterdam: Elsevier, 1996.

Conference paper

Bengtsson S, Solheim BG. Enforcement of data protection, privacy and security in medical informatics. In: Lun KC, Degoulet Piemme TE, Rienhoff 0, editors. MEDINFO 92. Proceedings of the 7th World Congress of Medical Informatics 1992 Sep 6-10; Geneva, Sweitzerland. Amsterdam: North- Hollalld, 1992: 1561-1565.


Kaplan SJ. Post- hospital home health care: the elderly's access and utilization [dissertation]. St. Louis (MO): Washington Univ, 1995.


Larsen CE, Trip R, Johnson CR, inventors; Novoste Corporation, assignee. Methods for procedures related to the electrophysiology of the heart. US patent 5, 529,067. 1995 Jun 25.

Other Published Material

Newspaper article

Lee G. Hospitalizations tied to ozone pollution: study estimates 50,000 admissions annually. The Washington Post 1996 Jun 21; Sect A:3 (col. 5).

Audiovisual material

HIV+ AIDS: the facts and the future [videocassette]. St Louis (MO): Mosby- Year Book; 1995.

Legal material

Public law:

Preventive Health Amendments of 1993, Pub. L. No. 103-183, 107Stat. 2226 (Dec. 14, 1993).

Unenacted bill

Medical Records Confidentiality Act of 1995, S.1360, 104th Cong., 1st Sess.(1995)

Code of Federal Regulations

Informed Consent, 42 C.F.R. Sect. 441. 257 (1995).


Increased Drug Abuse: the impact on the Nation's Emergency Rooms: Hearings Before the Subcomm. On Human Resources and Intergovernmental Relations of the House Comm. On Government Operations, 103rd Cong., 1st sess. (May 26, 1993).


North Carolina. Tuberculosis rates per 100,000 population, 1990 [demographic map]. Raleigh: North Carolina Dept. of Environment, Health, and Natural Resources, Div of Epidemiology; 1991.

Computer program

Smith Fred. Idea Link (computer program) version 3.12. Athens (GE): Univ of Georgia, 1992

Dictionary and similar references

Stedman's medical dictionary. 26th ed. Baltimore: Williams & Wilkins; 1995. Apraxia; pp. 119-120.

Unpublished Material

In press

Leshner AI. Molecular mechanism of cocaine addiction. N Engl J Med. In press 1996.

Electronic Material

Journal article in electronic format

Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis [Serial online] 1995 Jan- Mar (cited 1996 Jun 5]; 1(1) : (24 screens]. Available from: URL:

Monograph in electronic format

CDI, clinical dermatology illustrated [Monograph on CD- ROM] Reeves JA- r, Maibach H. CMEA Multimedia Group, producers, 2nd ed. Version 2.0 San Diego: CMEA; 1995.

Computer file

Hemodynamics III: the ups and downs of hemodynamics [computer program]. Version 2.2 Orlando (FI): Computerized Educational Systems; 1993.

Electronic material


Anderson SC, Poulsen KB. Anderson's electronic atlas of hematology [CD-ROM]. Philadelphia: Lipincott Williams & Wilkins; 2002.

Electronic Page/ Web site

Cancer- Pain or [homepage on the Internet] New York: Association of Cancer Online Resources , INC.; C2000-2001 [updated 2002 May 16; cited 2002 Jul 9]. Available from:

Part of an electronic page/ Web site

American Medical Association [homepage on the Internet]. Chicago the Association c1995-2002 [updated 2001 Aug 23; cited 2002 Aug 12]. AMA Office of Group Practice Liaison; about 2 screens]. Available from:

Data base in Internet


Who's Certified [database on the Internet]. Evanston (IL): The American Board of Medical Specialists. C2000-(cited 2001 Mar 8]. Available from:


Jablonski S. Online Multiple Congential Anomaly/ Mental Retardation (MCA/MR) Syndromes[database on the Internet]. Bethesda(MD): National Library Of Medicine (US). C1999[updated 2001 Nov 20; cited 2002 Aug 12]. Available from

Part database in Internet

MeSH Browser [database on the Internet]. Bethesda (MD): National Library of Medicine (US); 2002-[cited 2003 Jun 10]. Meta –analysis; unique ID: DO15201; [about 3p.]. Available from: update weekly.

Recommendations for the use of References

References constitute an important section in a scientific work. Careful selection of relevant documents gives soundness to theorical expression in a text and it is an important source of information for readers.

The following presents a series of indications to elaborate references based on the Uniform Requirements (Vancouver style).

References should be numbered consecutively in the order in which they are first mentioned in the text. Some journal instructions to authors recommend the use of Arabic numerals on superscript and without parentheses.

When there are more than more than one citation, these must be separated by commas, but if they are consecutive, the first and last one should be separated by a dash.

When an author is mentioned in the text, its numbered reference is written after the authors' name. If the project is done by more than two authors, the first one is cited followed by the et al abbreviation.

Only author's personal consulted references should be included. Citing works through third party opinions can be subject of inexistent opinions. Frequently, a work can be wrongly cited and contribute to perpetuate citation errors.

It is recommended not to include written works in uncommon languages. If, for some special reason, it is a must to cite them and they are not Latin type, it is recommended to translate the title to English or Spanish. PubMed translates to English and puts them between brackets. If it is cited through its abstract, this particularity must be specified, putting between brackets after the title [Abstract].

It is recommended not to cite journals translated to Spanish. It is advisable to find the citation of the original version, since it is easier to localize an original than a translated version, besides an original document is more reliable.

Updated documents should be cited. Some journals establish that they must not be older than five years, preferably those of the two last years. Historical or not current references of documents, can be cited as an alternative.

In order to adequately cite electronic material not present in the Instructions for the Authors it is recommended to consult the document on citation of references on Internet, published by The National Library of Medicine of USA, or the International Standards Organization (ISO 690-2) norm of electronic material. It is recommended not to include unpublished documents in the references such as: reports, conference proceedings, protocols, etc., but they can be mentioned as footnotes with the legend "unpublished observations". Its localization, identification and access can result very difficult. They happen to be documented include without any legal sustenance, for which they are not kept in libraries or documentation centers.

References to papers accepted but not yet published should be designated as "in press" or "forthcoming"; authors should obtain written permission to cite such papers as well as verification that they have been accepted for publication. Information from manuscripts submitted but not accepted should be cited as footnotes with the legend "unpublished observations" with written permission from the source.

Avoid using abstracts as references, unless it is a very justified motive. Complete documents should be consulted. Neither cite a "personal communication" unless it provides essential information not available from a public source, in which case the name of the person and date of communication should be included as footnotes. For scientific articles, authors should obtain written permission. Once references are completed, make sure citations correspond in the text and designated numbered in the references.


Type or print out each table with double spacing on a separate sheet of paper. Do not submit tables as photographs. Number tables consecutively in the order of their first citation in the text and supply a brief title for each. Give each column a short or abbreviated heading. Place explanatory matter in footnotes, not in the heading. Explain in footnotes all nonstandard abbreviations that are used in each table. Footnotes use the following symbols, in this sequence: *, †, ‡, §, ¦, **, ††, ‡‡.

Identify statistical measures of variations, such as standard deviation and standard error of the mean.

Do not use internal horizontal and vertical rules. Be sure that each table is cited in the text. If you use data from another published or unpublished source, obtain permission and acknowledge them fully.

The use of too many tables in relation to the length of the text may produce difficulties in the layout of pages. Examine issues of the journal to which you plan to submit your paper to estimate how many tables can be used per 1000 words of text.

The editor, on accepting a paper, may recommend that additional tables containing important backup data too extensive to publish be deposited with all archival service, such as the National Auxiliary Publication Service in the United States, or made available by the authors. In that event an appropriate statement will be added to the text. Submit such tables for consideration with the paper.

Illustrations (Figures)

Submit the required number of complete sets of figures. Figures should be professionally drawn and photographed; freehand or typewritten lettering is unacceptable. Instead of original drawings, x-ray films, and other material, send sharp, glossy, black-and-white photographies , usually 127 x 173 mm (5 x 7 inches) but no larger than 203x 254 mm (8 x 10 inches). Letters, numbers, and symbols should be clear and even throughout and of sufficient size that when reduced for publication each item will still be legible. Titles and detailed explanations belong in the legends for illustrations not on the illustrations themselves.

Each figure should have a label pasted on its back indicating the number of the figure, author's name, and top of the figure. Do not write on the back of figures or scratch or mar them by using paper clips. Do not bend figures or mount them or cardboard.

Photomicrographs should have internal scale markers. Symbols, arrows, or letters used in photomicrographs should contrast with the background.

Figures should be numbered consecutively according to the order in which they have been first cited in the text. If a figure has been published, acknowledge the original source and submit written permission from the copyright holder to reproduce the material. Permission is required irrespective of authorship or publisher except for documents the public domain.

For illustrations in color, ascertain whether the journal requires color negatives, positive transparencies, or color prints. Accompanying drawings marked to indicate the region to be produced may be useful to editor. Some journals publish illustrations in color only if the author pays for the extra cost.

A "table" is a set of names, numbers and other data which is presented in a joint and orderly fashion, in columns or rows, such that the relationship that exists between is obvious.

Legends for illustrations

Type or print out legends for illustrations using double spacing starting on a separate page, with Arabic numerals corresponding to the illustrations. When symbols, arrows, numbers, or letters are used to identify parts of the illustrations, identify and explain each one clearly in the legend. Explain the internal scale and identify the method of staining in photomicrographs.

Units Measurement

Measurements of length, weight, and volume should be reported in metric units (meter, kilogram, or liter) or their decimal multiples. Temperatures should be given in degrees Celsius. Blood pressures should be given in millimeters of mercury.

All hematologic and clinical chemistry measurements should be reported in the metric system in terms of the International System of Units (SI). Editors may request that alternative or non-SI units be added by the authors before publication.

Abbreviations and Symbols

Use only standard abbreviations. Avoid abbreviations in the title and abstract. The full term for which an abbreviations stands should precede its first use in the text unless it is a standard unit of measurements.

Sending the Manuscript to the Journal

Send the required number of copies of the manuscript in a heavy-paper envelope, enclosing the copies and figures in cardboard, if necessary, to prevent the photographs from being bent. Place photographs and transparencies in a separate heavy-paper envelope.

Manuscripts must be accompanied by a covering letter signed by all coauthors.

This letter must include. a)Information on prior or duplicate publication or submission elsewhere of any part of the work as defined earlier in this document; b) A statement of financial or other relationships that might lead to a conflict of interest (see below); c) a statement that the manuscripts has been read and approved by all the authors, that the requirements for authorship as stated earlier in this document have been met, and that each author believes that the manuscript represents honest work; and d) the name, address, and telephone number of the corresponding author, who is responsible for communicating with the other authors about revisions and final approval of the proofs. The letter should give any additional information that may be helpful to the editor, such as the type of article in the particular journal that the manuscript represents and whether the author(s) would be willing to meet the cost of reproducing color illustrations.

The manuscripts must be accompanied by copies of any permission to reproduce published material, to use illustrations or to name people for their contributions.



Definition or a Peer- Reviewed Journal

A peer-reviewed journal is one that has submitted most of its published articles for review by experts who are not part of the editorial staff. The number and kind of manuscripts sent for review, the number of reviewers , the reviewing procedures, and the use made of the reviewer's opinions may vary, and therefore each journal should publicly disclose its policies in its instructions to authors for the benefit of readers and potential authors.

Editorial Freedom and Integrity

Owners and editors of medical journals have a common endeavor, the publication of a reliable and readable journal, produced with due respect for the stated aims of the journals and for costs. The functions of owners and editors, however are different. Owners have the right to appoint and dismiss editors and to make important business decisions in which editors should be involved to the fullest extent possible. Editors must have full authority for determining the editorial content of the journal. This concept of editorial freedom should be resolutely defended by editors even to the extent of their placing their positions at stake. To secure this freedom in practice, the editor should have direct access to the highest level of ownership, not only to a delegated manager.

Editors of medical journals should have a contract that clearly states the editor's rights and duties in addition to the general terms of appointment and that defines mechanism for resolving conflict.

An independent editorial advisory board may be useful in helping the editor establish and maintain editorial policy.

All editors and editor's organizations have the obligation to support the concept of editorial freedom and to draw major transgressions of such freedom to the attention of the international medical community.

Conflict of interest

Conflict of interest for a given manuscript exists when a participant in the peer reviews and publication process-author, reviewer, and editor-has ties to activities that could inappropriately influence his or her judgment, whether or not judgment is in fact affected. Financial relationships with industry (for example, through employment, consultancies, stock ownership, honoraria, expert testimony), either directly or through immediate family, are usually considered to be the most important conflicts of interest. However, conflicts can occur for other reasons, such as personal relationships, academic competition, and intellectual passion.

Public trust in the peer reviews process and the credibility of published articles depend in part on how well conflict of interest is handled during writing, peer review, an editorial decision making. Bias can often be identified and eliminated by careful attention to the scientific methods and conclusions of the work. Financial relationships and their effects are less easily detected than other conflicts of interest. Participants in peer review and publication should disclose their conflicting interest, and the information should be made available so that others can judge their effects for themselves.

Because readers may be less able to detect bias in review articles and editorials than in reports of original research, some journals do not accept reviews and editorials from authors with a conflict of interest.


When they submit a manuscript, whether an article or a letter, authors are responsible for recognizing and disclosing financial and other conflicts of interest that might bias their work. They should acknowledge in the manuscript all financial support for the work and other financial or personal connections to the work.


External peer reviewers should disclose to editors any conflicts of interest that could bias their opinions of the manuscripts, and they should disqualify themselves from re viewing specific manuscripts if they believe it to be appropriate. The editors must be made aware of reviewer's conflicts of interest to interpret the reviewer's conflicts of interest to interpret the reviews and judge for themselves whether the reviewer should be disqualified. Reviewers should not use knowledge of the work, before its publication, to further their own interest.

Editors and Staff

Editors who make final decisions about manuscripts should have no personal or financial involvement in any of the issues they might judge. Other members or the editorial staff, if they participate in editorial decisions, should provide editors with a current description of their financial interests (as they might relate to editorial judgments)) and disqualify themselves from any decisions where they have a conflict of interest. Published articles and letters should include a description of all financial support and any conflict of interest that, in the editor's judgment, readers should know about. Editorial staff should not use the information gained through working with manuscripts for private again.




Scientists have an ethical obligation on submit creditable research results for publication. Moreover, as the person directly responsible for their works, scientist should not enter into agreements that interfere with their control over the decision to publish the papers they write.

The manuscripts must acknowledge if any economic help was received for carrying out their project, as well as other personal or economical connections of the project.

Editors and Staff

Editors who make final decisions about manuscripts should have no personal or financial involvement in any of the issues they might judge. Other members or the editorial staff, if they participate in editorial decisions, should provide editors with a current description of their financial interests (as they might relate to editorial judgments) and disqualify themselves from any decisions where they have a conflict of interest. Published articles and letters should include a description of all financial support and any conflict of interest that, in the editor's judgment, readers should know about. Editorial staff should not use the information gained through working with manuscripts for private again.

Editors should require authors to describe the role of outside sources of project support if any, in study design; in the collection, analysis and interpretation of data; and in the writing of the report. If the supporting source has no such involvement, the authors should so state. Because the biases potentially introduced by the direct involvement of supporting agencies in research are analogous to the methodological biases of other sorts (e.g., study design, statistical and psychological factors), the type and degree of involvement of the supporting agency should be described in the Methods section. Editors should also require disclosure of whether or not the supporting agency controlled or influenced the decision to submit the final manuscript of publications

Corrections, Retractions and "Expressions of concern"

Editors must assume initially that authors are reporting work based on honest observations. Nevertheless, two types of difficulty may arise.

First, errors may be noted in published articles that require the publication of a correction or erratum of part of the work. The corrections should appear on a numbered page, be listed in the contents page, included the complete original citation, and link to the original article and vice versa if online. It is conceivable that a error could be so serious as to vitiate the entire body of the work, but this is unlikely and should be handled by editors and authors on an individual basis. Such an error should not be confused with inadequacies exposed by the emergence of new scientific information in the normal course of research. The latter require no corrections or withdrawals. The second type of difficulty is scientific fraud. If substantial doubts arise about the honesty or integrity of works, either submitted or published, it is the editor's responsibility to ensure that the question is appropriately pursued, usually by the author's sponsoring institution. However, it is not ordinarily the task of editors to conduct a full investigation or to make a determination; that responsibility lies the institution where the work was done or with the funding agency. The editor should be promptly with informed of the final decision, and if a fraudulent paper has been published, the journal must print a retraction. If this method of investigation does not result in a satisfactory conclusion, the editor may choose to conduct his or her own investigation. As an alternative to retraction the editor may choose to publish an expression of concern about aspects of the conduct of integrity of the work.

The retraction or expression of concern, so labeled, should appear on a numbered page in a prominent section of the printed. Journal as well as in the online version, be listed in the contents page, and include in its heading the title of the original article. It should not simply be a letter to the editor. Ideally, the first author should be the name in the retraction as in the article, although under certain circumstances the editor may accept retractions by other responsible persons. The text of the retraction should explain why the article is being retracted an include a full original citation reference to it.

The validity of previous work by the author of a fraudulent paper cannot be assumed. Editors may ask the author's institution to assure them of the validity of earlier work publisher in their journals or to retract it. If this is not done, editors may choose to publish an announcement expressing concern that the validity of previously.


Manuscripts should be reviewed with due respect for authors 'confidentiality. In submitting their manuscripts for review, authors entrust editors with the results of their scientific work and creative effort, on which their reputation and career may depended. Author's right may be violated by disclosure of the confidential details of the review of their manuscript. Reviewers also have right to confidentiality, which must be respected by the editor. Confidentiality may have to be breached if dishonesty or fraud is alleged but otherwise must be honored.

Editors should not disclose information about manuscripts (including their receipt, their content, their status in the reviewing process, their criticisms by reviewers, or their ultimate fate) to anyone other than the authors themselves and reviewers.

Editor should make clear to their reviewers that manuscripts sent for review are privileged communications and are the private property of the authors. Therefore, reviewers and members of the editorial staff should respect the authors' rights by not publicly discussing the author's work or appropriating their ideas before the manuscript is published. Reviewers should not be allowed to make copies of manuscript for their files and should be prohibited from sharing it with others, except with the permission of the editor. Editors should not keep copies of rejected manuscripts. Opinions differ on whether reviewers should remain anonymous. Some editors require their reviewers to sign the comments returned to author, but most either request that reviewers 'comments not be signed or leave the choice to the reviewer. When comments are not signed the reviewers' identity must not be revealed to the author or anyone else.

Some journals publish reviewer's comments with the manuscript. No such procedure should be adopted without the consent of the authors and reviewers. However, reviewers 'comments may be sent to other reviewers of the same manuscript, and reviewers may be notified of the editor's decision.

Medical Journals and the Popular Media

The public's interest in news medical research has led the popular media to compete vigorously to get information about research as soon as possible. Researchers and institutions sometimes encourage the reporting of research in the popular media before full publication in a scientific journal by holding a press conference or giving interviews.

The public is entitled to important medical information without unreasonable delay, and editors have a responsibility to play their part in this process. Doctors, however, need to have reports available in full detail before they can advise their patients about the reports' conclusions. In addition, media reports or scientific research before the work has been peer reviewed and fully published may lead to the dissemination of inaccurate or premature conclusions.

Editors may find the following recommendations useful as they seek to establish policies on these issues:

1. Editor can foster the orderly transmission of medical information from research, though per- reviewed journals, to the public. This can be accomplished by an agreement with authors that they will to publicize their work while their manuscript is under consideration or awaiting publication and an agreement with the media that they will not release stories before publication in the journal, in return for which the journal will cooperate with them in preparing accurate stories (see below).

2. Very little medical research has such clear and urgently important clinical implications for the public's health that the news must be released before full publication in a journal. In such exceptional circumstances, however, appropriate authorities responsible for public health should make the decision and the appropriate are authorities wish to have manuscripts considered by a particular journal; the editor should be consulted before any public release. If editors accept the need for immediate release, they should waive their policies limiting prepublication publicity.

3. Policies designed to limit prepublication publicity should not apply to account in the media of presentations at scientific meetings or to the abstracts form these meetings (see Redundant or Duplicate Publication). Researchers who present their work at a scientific meeting should feel free to discuss their presentations with reporters, but they should be discouraged from offering more details about their study than was presented in their talk.

4. When an article is soon to be published, editors may wish to help the media prepare accurate reports by providing news releases, answering questions, supplying advance copies of the journal, or referring reporters to the appropriate experts. This assistance should be contingent on the media's cooperation in timing their release of stories to coincide with the publication of the article.


Most medical journals carry advertising, which generates income for their publishers, but advertising must not be allowed to influence editorial decisions. Journals should have format, explicit, written policies for advertising in both print and electronic versions; website advertising policy should parallel policy for the print version as much as possible. Editors must have full and final authority for approving advertisements and enforcing advertising policy.

Where independent bodies for reviewing advertising exist editors should make use of their judgments. Readers should be able to distinguish readily between advertising and editorial material. The juxtaposition of editorial and advertising material on the same products or subjects should be avoided. Interleafing advertising pages within articles discourages readers by interrupting the flow of editorial content, and should be discouraged. Advertising should not be sold on the condition that it will appear in the same issue as a particular article.

Journals should not be dominated by advertising, but editors should be careful about publishing advertisements form only one or two advertisers, as readers may perceive that these advertisers have influenced the editor.

Journal should not carry advertisements for products that have proved to be seriously harmful to health- for example, tobacco. Editors should ensure that existing regulatory or industry standards for advertisements specific to their country are enforced, or develop their own standards. The interests of organizations or agencies should not control classified and other non-display advertising, except where required by law. Finally, editors should consider all criticisms of advertisements for publication.


Supplements are collections of papers that deal with related issues or topics, are published as a separate issue of the journal or as part of a regular issue, and are usually funded by sources other than the journal's publisher. Supplements can serve useful purposes: education exchange of research information, ease of access focused content, and improved cooperation between academic and corporate entities. Because funding sources can bias the content of supplements through the choice of topics and viewpoints, journals should consider adopting the following principles.

1. The journal editor must take full responsibility for the policies, practices, and content of supplements. This means that the journal editor who includes a supplement must approve the decision of the supplement editor or responsible and keep the authority in relation to denying the article's publication.

2. The sources of funding for the research, publication, and the products the funding source make that are considered in the supplement should be clearly stated and prominently located in the supplement, preferably on each page. Whenever possible, funding should come from more than one sponsor.

3. Advertising in supplements should follow the same policies as those of the rest the journal.

4. Journal editors must enable readers to distinguish readily between ordinary editorial pages and supplement pages.

5. The organization that finances the supplement must not correct the edition.

6. Journal editors and supplement editors must not accept personal favors or personal remuneration from sponsors of supplements.

7. Secondary publication in supplements should be clearly identified by citation of the original paper. Supplement should avoid redundant publication.

Competing Manuscripts Based on the Same Study

The editors may receive manuscripts of several authors that offer contradictory interpretations if the same study. The editors, in this case have to decide if they accept the review of opposite manuscripts sent more or less simultaneously by different groups or authors, or if they admit the evaluation of one of them even knowing that the antagonist manuscript will be sent to other journal. Keeping aside the property of data in question , what it is said here is how editors should proceed when opposite manuscripts based on the same study are received.

Two kinds of competing submissions are considered: submissions by coworkers who disagree on the analysis and interpretation of their study, and submissions by coworkers who disagree on what the facts are and which data should be reported.

Setting aside the unresolved questions of ownership or the data, the following general observations may help editors and others dealing with these problems.

Differences in Reported Methods or Results

If the dispute centers on differing opinions of what was actually done or observed during the study, the journal editor should refuse publication until the disagreement is resolved. Peer review cannot be expected to resolve such problems. If there are allegations of dishonesty or fraud, editors should inform the appropriate authorities; authors should be notified of an editor's intention to report a suspicion of research misconduct.

The aforementioned cases should be distinguished from other cases in which independent authors based on different analyses from data extracted from public sources. In these circumstances, multiple submissions may be justified or even there can be a good reason for publishing more than one manuscript, since different analytical approaches may be complementary an equally valid.

Biomedical journals should provide its readership with a mechanism for submitting comments, questions, or criticisms about published articles and where the authors of these articles may respond.

This will likely, but not necessarily, takes the form of a correspondence section or column. The lack of this section deprives the reader from the possibility to respond in the same issue in which the original was published.



The International Committee of Medical Journal Editors (ICMJE) is an informal group whose participants fund their work on the URM. The ICMJE is not a membership organization. Editors are encouraged to join organizations that offer educational programs, meetings, publications, and other opportunities to interact with colleagues. Examples of such groups are given below: Council of Science Editors (CSE); The European Association of Science Editors (EASE);Society for Scholarly Publishing (SSP), The World Association of Medical Editors (WAME)



The ICMJE participating journals and organizations and their representatives who approved the revised Uniform Requirements in May 2000 should be cited as authors of the documents on this website: Frank Davidoff, Annals of Internal Medicine; Fiona Godlee, BMJ; John Hoey, Canadian Medical Association Journal; Richard Glass, JAMA; John Overbeke, Nederlands Tijdschrift voor Geneeskunde; Robert Utiguer, New England Journal of Medicine; M. Gary Nicholls, New Zealand Medical Journal; Richard Horton, The Lancet; Magne Nylenna, Tidsskrift for Den Norske legeforening; Liselotte Hojgaard, Ugeskrift for Laeger, Sheldon Kotzian, U.S. National Library of Medicine.



The following members of the ICMJE helped author the 1997 version and should be acknowledged in citations of the May 2000 version : Linda Hawes Clever, Western Journal of Medicine; George Lundberg, JAMA; Richard G. Robinson, New Zealand Medical Journal; Richard Smith, BMJ; Bruce P. Squires, Canadian Medical Association Journal; Martin VanDer Weydent, The Medical Journal of Australia; and Patricia Woolf, Princeton University.

This document may be copied and distributed without charge for not-for-profit, educational purposes


1 International Committee of Medical Journal Editors, Uniform Requirements for Manuscripts submitted to Biomedical Journals. Ann Intern Med. 1997; 126:36-47.


Mtra. Claudia de León Torres
Revista Odontológica Mexicana
Dirección: Facultad de Odontología
Ciudad Universitaria, UNAM.
Deleg. Coyoacán, México D.F.
C.P. 04510
Correo electrónico:,



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