Updated: Jul 11, 2021
The Vancouver system, also known as Vancouver reference style or the author–number system, is a citation style that uses numbers within the text that refer to numbered entries in the reference list. It is popular in the physical sciences and is one of two referencing systems normally used in medicine, the other being the author–date, or "Harvard", system. Vancouver style is used by MEDLINE and PubMed.
References are numbered consecutively in order of appearance in the text – they are identified by Hindu-Arabic numerals in parentheses (1), square brackets , superscript1, or a combination. The number usually appears at the end of the material it supports, and an entry in the reference list would give full bibliographical information for the source:
Blood loss and the number of patients requiring post-operative blood transfusions were significantly greater, but operation and fluoroscopy times were significantly shorter, for the DHS versus the PFNA group.
And the entry in the reference list would be:
1. Xu YZ, Geng DC, Mao HQ, Zhu XS, Yang HL (2010). "A comparison of the proximal femoral nail antirotation device and dynamic hip screw in the treatment of unstable pertrochanteric fracture". J Int Med Res. 38 (4): 1266–1275. doi:10.1177/147323001003800408. PMID 20925999. S2CID 20812098.
Several descriptions of the Vancouver system say that the number can be placed outside the text punctuation to avoid disruption to the flow of the text, or be placed inside the text punctuation, and that there are different cultures in different traditions. The first method is recommended by some universities and colleges, while the latter method is required by scientific publications such as the MLA and IEEE except for in the end of a block quotation. (IEEE are using Vancouver style labels within brackets, for example to cite the first reference in the list, but otherwise refer to Chicago Style Manual.) The original Vancouver system documents (the ICMJE recommendations and Uniform Requirements for Manuscripts Submitted to Biomedical Journals) do not discuss placement of the citation mark.
Format of citations
Different formats exist for different types of sources, e.g. books, journal articles, etc.
Format of names
Formatting for all names (e.g., authors, editors, etc.) is the same.
General rules for names:
List names in the order they appear in the text
Enter surname (family or last name) first for each author
Capitalize surnames and enter spaces within surnames as they appear in the document cited on the assumption that the author approved the form used. For example: Van Der Horn or van der Horn; De Wolf or de Wolf or DeWolf.
Convert given (first) names and middle names to initials, for a maximum of two initials following each surname
Give all authors, regardless of the number
Separate author names from each other by a comma and a space
End author information with a period
See exceptions for author in Appendix F: Notes for Citing MEDLINE/PubMed.
Although Citing Medicine does not explicitly mandate merging initials (e.g. "R. K." would be merged into "RK"), the examples used throughout the book do.
Standard journal articles
Leurs R, Church MK, Taglialatela M. H1-antihistamines: inverse agonism, anti-inflammatory actions and cardiac effects. Clin Exp Allergy. 2002 Apr;32(4):489-498.
Tashiro J, Yamaguchi S, Ishii T, Suzuki A, Kondo H, Morita Y, Hara K, Koyama I. Inferior oncological prognosis of surgery without oral chemotherapy for stage III colon cancer in clinical settings. World J Surg Oncol. 2014 May 10;12(1):145.
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.
Thomas MC. Diuretics, ACE inhibitors and NSAIDs – the triple whammy. Med J Aust. 2000;172:184-185.
The NLM lists all authors for all articles, because it is appropriate for capturing all authors and all of their publications in the MEDLINE database to be found by searches. However, in the reference lists of articles, most journals truncate the list after 3 or 6 names, followed by "et al." (which most medical journals do not italicize):
Guilbert TW, Morgan WJ, Zeiger RS, Mauger DT, Boehmer SJ, Szefler SJ, et al. Long-term inhaled corticosteroids in preschool children at high risk for asthma. N Engl J Med. 2006 May 11;354(19):1985-1997.
Optionally, a unique identifier (such as the article's DOI or PMID) may be added to the citation:
von Itzstein M, Wu WY, Kok GB, Pegg MS, Dyason JC, Jin B, et al. Rational design of potent sialidase-based inhibitors of influenza virus replication. Nature. 1993 Jun 3;363(6428):418-423. PMID 8502295.
NLM elides ending page numbers and uses a hyphen as the range indicating character (184-5). Some journals do likewise, whereas others expand the ending page numbers in full (184-185), use an en dash instead of a hyphen (184–5), or both (184–185).
Virtually all medical journal articles are published online. Many are published online only, and many others are published online ahead of print. For the date of online publication, at the end of the citation NLM puts "[Epub Year Mon Day]" (for online-only publication) or "[Epub ahead of print]" for online ahead of print (with the month and day following the year in its normal position). In contrast, AMA style puts "[published online Month Day, Year]" at the end of the article title. It no longer uses the term "Epub" and no longer includes the words "ahead of print". It omits the year from its normal location after the journal title abbreviation if there is no print data to give (online-only publication).
The titles of journals are abbreviated. There are no periods in the abbreviation. A period comes after the abbreviation, delimiting it from the next field. The abbreviations are standardized. The standardization was formerly incomplete and internal to organizations such as NLM. It is now formalized at the supraorganizational level (see also: ANSI Z39.5 and ISO 4: Information and documentation -- Rules for the abbreviation of title words and titles of publications).
Articles not in English
As per journal articles in English:
Forneau E, Bovet D. Recherches sur l'action sympathicolytique d'un nouveau dérivé du dioxane. Arch Int Pharmacodyn. 1933;46:178-191. French.
The NLM adds an English translation of the title enclosed in square brackets right after the title. The language is specified in full after the location (pagination), followed by a period.
Surname Initial(s). Book title. Edition - if available: Publisher, place of publication; Year .
Rang HP, Dale MM, Ritter JM, Moore PK. Pharmacology. 5th ed. Edinburgh: Churchill Livingstone; 2003.
Editor(s) or compiler(s) as authors
Beers MH, Porter RS, Jones TV, Kaplan JL, Berkwits M, editors. The Merck manual of diagnosis and therapy. 18th ed. Whitehouse Station (NJ): Merck Research Laboratories; 2006.
Authored chapter in edited publication
Glennon RA, Dukat M. Serotonin receptors and drugs affecting serotonergic neurotransmission. In: Williams DA, Lemke TL, editors. Foye's principles of medicinal chemistry. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2002.
World Health Organization (WHO). Mortality country fact sheet 2006 [internet]. Geneva: WHO; 2006. Available from: www.who.int/whosis/mort_emro_pak_pakistan.pdf