Uniform requirements for manuscripts submitted to biomedical journals

International Committee of Medical Journal Editors

[This page was last updated 5 May 2000]

• Introduction
• Issues to consider before submitting a manuscript
  • Redundant or duplicate publication
  • Acceptable secondary publication
  • Protection of patients' rights to privacy
• Requirements for submission of manuscripts
  • Summary of technical requirements
  • Manuscripts on diskettes
  • Preparation of manuscripts
    • Title page
      • Authorship
    • Abstract and key words
    • Introduction
    • Methods
      • Ethics
      • Statistics
    • Results
    • Discussion
    • Acknowledgements
    • References
    • Tables
    • Illustrations
    • Units of measurement
    • Abbreviations and symbols
    • Sending the manuscript to the journal
• Additional statements:
  • Definition of a peer-reviewed journal
  • Editorial freedom and integrity
  • Conflict of interest
  • Corrections, retractions and "expressions of concern" about research findings
  • Confidentiality
  • Medical journals and the popular media
  • Advertising
  • Supplements
  • The role of the correspondence column
  • Competing manuscripts based on the same study
  • Citing uniform requirements
  • Policies for posting biomedical journal on the internet
  • Statement on project-specific industry support for research

The committee has produced four previous editions of the uniform requirements. 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. Each statement has been published in a scientific journal. [The statements were published in the Feb. 15, 1997, issue of CMAJ.]

This fifth edition is an effort to reorganize and reword the uniform requirements in order to increase clarity and address concerns about rights, privacy, descriptions of methods and other matters. The total content of the document may be reproduced for educational, not-for-profit 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 the 1997 document in their instructions to authors.

Inquiries and comments should be sent to Faith McLellan, PhD, ACP/ASIM, 190 Independence Mall West, Philadelphia PA 19106-1572, USA; tel. 215 351-2559, fax 215 351-2644, e-mail fmclellan@mail.acponline.org.

Publications represented on the ICMJE in 2000 are the following: Annals of Internal Medicine, British Medical Journal, Canadian Medical Association Journal, Journal of the American Medical Association, The Lancet, Medical Journal of Australia, New England Journal of Medicine, New Zealand Medical Journal, Tidsskrift for Den Norske Laegeforening, Western Journal of Medicine and Index Medicus, Ugeskrift for Laeger and Nederlands Tijdschrift voor Geneeskunde.

It is important to emphasize what these uniform 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. (But many journals have drawn on them for elements of their publication styles.)

Second, if authors prepare 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 that journal and the types of papers that may be submitted (e.g., 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 of articles and approved abbreviations.

[CMAJ's instructions appear in the first issue of each volume.]

Participating journals are expected to state in their instructions to authors that their requirements are in accordance with the uniform requirements and to cite a published version.

Table of contents

Readers of primary source periodicals deserve to be able to trust that what they are reading is original unless it is clearly stated 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 described in a paper that has been submitted or accepted for publication elsewhere, in print or in 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 an 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, an 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 whom 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 deal with 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 duplicate 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.

Table of contents

Acceptable secondary publication

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

• The priority of the primary publication is respected by a publication interval of at least 1 week (unless specifically negotiated otherwise by both editors).

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

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

• A 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.

Table of contents

Protection of patients' rights to privacy

Identifying details should be omitted if they are not essential, but patient data should never be altered or falsified in an attempt to attain anonymity. Complete anonymity is difficult to achieve, and informed consent should be obtained if there is any doubt. For example, masking the eye region in photographs of patients is inadequate protection of anonymity.

The requirement for informed consent should be included in the journal's instructions for authors. When informed consent has been obtained it should be indicated in the published article.

Table of contents

• Double space all parts of manuscripts.

• Begin each section or component on a new page.

• Review the sequence: title page, abstract and key words, text, acknowledgements, references, tables (each on a separate page), legends for illustrations.

• Illustrations (unmounted, good-quality prints) should be no larger than 203  × 254 mm (8 × 10 in).

• Include permission to reproduce previously published material or to use illustrations that may identify human subjects.

• Enclose transfer of copyright and other forms.

• Submit the required number of paper copies.

• Keep copies of everything submitted.

Table of contents

Manuscripts on diskettes

When submitting disks, authors should:

1. Be certain to include a print-out of the manuscript version on the diskette.
2. Put only the latest version of the manuscript on the diskette.
3. Name the file clearly.
4. Label the diskette with the file format 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.

Table of contents

Preparation of manuscripts

Type or print out the manuscript on white bond paper 216  × 279 mm (8 1/2  × 11 in) or ISO A4 (212  × 297 mm), with margins of at least 25 mm (1 in). Type or print on only one side of the paper. Use double spacing throughout, including title page, abstract, text, acknowledgements, references, tables and legends for illustrations. Number the pages consecutively, beginning with the title page. Put the page number in the upper or lower right-hand corner of each page.

Title page

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, with his or her highest academic degree(s) and institutional affiliation; (c) the name of the department(s) and institution(s) to which the work should be attributed; (d) disclaimers, if any; (e) the name and address of the author responsible for correspondence about the manuscript; (f) the name and address of the author to whom requests for reprints should be addressed or a statement that reprints will not be available from the authors; (g) the source(s) of support in the form of grants, equipment, drugs or all of these; and (h) a short running head or foot line (no longer than 40 characters, counting letters and spaces) at the foot of the title page.

Authorship

All 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 1) substantial contributions to conception and design, or acquisition of data, or analysis and interpretation of data; 2) drafting the article or revising it critically for important intellectual content; and 3) final approval of the version to be published. Conditions 1, 2, and 3 must all be met. Acquisition of funding, the collection of data, or general supervision of the research group, by themselves, do not justify authorship.

Editors may ask authors to describe what each contributed; this information may be published.

Increasingly, multicentre trials are attributed to a corporate author. All members of the group who are named as authors, either in the authorship position below the title or in a footnote, should fully meet the above criteria for authorship. Group members who do not meet these criteria should be listed, with their permission, in the Acknowledgement or in an appendix (see Acknowledgements).

The order of authorship should be a joint decision of the coauthors. Because the order is assigned in different ways, its meaning cannot be inferred accurately unless it is stated by the authors. Authors may wish to explain the order of authorship in a footnote. In deciding on the order, authors should be aware that many journals limit the number of authors listed in the table of contents and that the NLM lists in MEDLINE 25 authors (it lists 24 and the last author if there are more than 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). The abstract should state the purposes of the study or investigation, basic procedures (selection of study subjects or laboratory animals, observational and analytical methods), main findings (specific data and their statistical significance, if possible) and the principal conclusions. It should emphasize new and important aspects of the study or observations.

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 that may be published with the abstract. Use terms from the medical subject headings (MeSH) list of Index Medicus; if suitable MeSH terms are not yet available for recently introduced terms, present terms may be used.

Introduction

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

Methods

Describe clearly your selection of the observational or experimental subjects (patients or laboratory animals, including controls). 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 women 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 Statistics); provide references and brief descriptions for methods that 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), dosage(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 statistical 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.

Ethics

When reporting experiments on human subjects, indicate whether the procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional or regional) and with the Helsinki Declaration of 1975, as revised in 1983. Do not use patients' names, initials or hospital numbers, especially in illustrative material. When reporting experiments on animals, indicate whether the institution's or the National Research Council's guide for, or any national law on, the care and use of laboratory animals was followed.

Statistics

Describe statistical 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 any blinding of observations. Report complications of treatment. Give numbers of observations. Report losses to observation (e.g., dropouts from a clinical trial). When possible, references for the study design and statistical methods should be to standard works (with page numbers 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 analyse them. Restrict tables and illustrations 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," "correlation" and "sample." Define statistical terms, abbreviations and most symbols.

Results

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.

Discussion

Emphasize the new and important aspects of 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 claiming priority and alluding to work that has not been completed. State new hypotheses when warranted, but clearly label them as such. Recommendations, when appropriate, may be included.

Acknowledgements

At an appropriate place in the article (title-page footnote or appendix to the text; see the journal's requirements) one or more statements should specify (a) contributions that need acknowledging but do not justify authorship, such as general support by a department chair; (b) acknowledgements of technical help; (c) acknowledgements of financial and material support, which should specify the nature of the support; and (d) relationships that may pose a conflict of interest (this topic will be covered in the statements in the Feb. 15 issue).

Persons who have contributed intellectually to the paper but whose contributions do not justify authorship may be named and their function or contribution described (e.g., "scientific adviser," "critical review of study proposal," "data collection" or "participation in clinical trial"). Such persons must have given their permission to be named. Authors are responsible for obtaining written permission from persons acknowledged by name, because readers may infer their endorsement of the data and conclusions.

Technical help should be acknowledged in a paragraph separate from those acknowledging other contributions.

References

References should be numbered consecutively in the order in which they are first mentioned in the text. Identify references in text, tables and legends for illustrations by arabic numerals in parentheses. References cited only in tables or in legends should be numbered in accordance with the sequence established by the first identification in the text of the particular table or illustration.

Use the style of the examples that follow, 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 of Index Medicus. The list can also be obtained through the library's Web site (http://www.nlm.nih.gov).

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 not 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 txFor 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 requirements style (the Vancouver style) is based largely on an ANSI standard style adapted by the NLM for its databases (e.g., MEDLINE). Notes have been added where Vancouver style differs from the style now used by the NLM.

Articles in journals

• Standard journal article (List 6 authors, followed by "et al" if the number exceeds 6.) [Note: NLM now lists up through 25 authors; if there are more than 25 authors, NLM lists the first 24, then the last author, then et al.]

  Vega KJ, Pina I, Krevsky B. Heart transplantation is associated with an increased risk for pancreatobiliary disease. Ann Intern Med 1996 Jun 1;124(11):980-3.

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, this option is used throughout the examples in this document. NLM does not use the option.]

Vega KJ, Pina I, Krevsky B. Heart transplantation is associated with an increased risk for pancreatobiliary disease. Ann Intern Med 1996;124:980-3.

More than six authors

Parkin DM, Clayton D, Black RJ, Masuyer E, Friedl HP, Ivanov E, et al. Childhood leukaemia in Europe after Chernobyl: 5 year follow-up. Br J Cancer 1996;73:1006-12.

• Organization as author

  The Cardiac Society of Australia and New Zealand. Clinical exercise stress testing. Safety and performance guidelines. Med J Aust 1996;164:282-4.

• No author given

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

• Article not in English [Note: NLM translates the title to English, encloses the translation in square brackets and adds an abbreviated language designator.]

  Ryder TE, Haukeland EA, Solhaug JH. Bilateral infrapatellar seneruptur hos tidligere frisk kvinne. Tidsskr Nor Laegeforen 1996;116:41-2.

• Volume with supplement

  Shen HM, Zhang QF. Risk assessment of nickel carcinogenicity and occupational lung cancer. Environ Health Perspect 1994;102 Suppl 1:275-82.

• 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 and urine sialic acid in non-insulin dependent diabetes mellitus. Ann Clin Biochem 1995;32(Pt 3):303-6.

• 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):377-8.

• Issue with no volume

  Turan I, Wredmark T, Fellander-Tsai L. Arthroscopic ankle arthrodesis in rheumatoid arthritis. Clin Orthop 1995;(320):110-4.

• No issue or volume

  Browell DA, Lennard TW. Immunologic status of the cancer patient and the effects of blood transfusion on antitumor responses. Curr Opin Gen Surg 1993:325-33.

• 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.

• Type of article indicated as needed

  Enzensberger W, Fischer PA. Metronome in Parkinson's disease [letter]. Lancet 1996;347:1337.

  Clement J, De Bock R. Hematological complications of hantavirus nephropathy (HVN) [abstract]. Kidney Int 1992;42:1285.

• Article containing retraction

  Garey CE, Schwarzman AL, Rise ML, Seyfried TN. Ceruloplasmin gene defect associated with epilepsy in EL mice [retraction of Garey CE, Schwarzman AL, Rise ML, Seyfried TN. In: Nat Genet 1994;6:426-31]. Nat Genet 1995;11:104.

• Article retracted

  Liou GI, Wang M, Matragoon S. Precocious IRBP gene expression during mouse development [retracted in Invest Ophthalmol Vis Sci 1994;35:3127]. Invest Ophthalmol Vis Sci 1994;35:1083-8.

• Article with published erratum

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

Books and other monographs

[Note: Previous Vancouver style incorrectly had a comma rather than a semicolon between the publisher and the date.]

• Personal author(s)

  Ringsven MK, Bond D. Gerontology and leadership skills for nurses. 2nd ed. Albany (NY): Delmar Publishers; 1996.

• Editor(s), compiler(s) as author(s)

  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 p before pagination.]

  Phillips SJ, Whisnant JP. Hypertension and stroke. In: Laragh JH, Brenner BM, editors. Hypertension: pathophysiology, diagnosis, and management. 2nd ed. New York: Raven Press; 1995. p. 465-78.

• 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 P, Piemme TE, Rienhoff O, editors. MEDINFO 92. Proceedings of the 7th World Congress on Medical Informatics; 1992 Sep 6­10; Geneva, Switzerland. Amsterdam: North-Holland; 1992. p. 1561-5.

• Scientific or technical report

  Issued by funding/sponsoring agency:

  Smith P, Golladay K. Payment for durable medical equipment billed during skilled nursing facility stays. Final report. Dallas (TX): Dept. of Health and Human Services (US), Office of Evaluation and Inspections; 1994 Oct. Report No.: HHSIGOEI69200860.

  Issued by performing agency:

  Field MJ, Tranquada RE, Feasley JC, editors. Health ser-vices research: work force and educational issues. Washington: National Academy Press; 1995. Contract No.: AHCPR282942008. Sponsored by the Agency for Health Care Policy and Research.

• Dissertation

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

• Patent

  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 Ammendments of 1993, Pub. L. No. 103-183, 107 Stat. 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).

  Hearing:

  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).

• Map

  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.

• Book of the Bible

  The Holy Bible. King James version. Grand Rapids (MI): Zondervan Publishing House; 1995. Ruth 3:1-18.

• Dictionary and similar references

  Stedman's medical dictionary. 26th ed. Baltimore: Williams & Wilkins; 1995. Apraxia; p. 119-20.

• Classical material

  The Winter's Tale: act 5, scene 1, lines 13-16. The complete works of William Shakespeare. London: Rex; 1973.

Unpublished material