The Vancouver style is a numerical system.  This guide to Vancouver is based on Citing medicine: the NLM style guide for authors, editors & publishers and the Recommendations of the International Committee of Medical Journal Editors (ICMJE).

There are two main elements in the Vancouver citation style: in-text citations in your paper and the reference list at the end of your paper.

The in-text citation 

Notes on use of unique reference number

An Arabic numeral in parentheses is inserted in your text at the point where you refer to (cite) your source of information.

See this example:

An unhealthy diet, obesity and physical inactivity play a role in the onset of Type 2 diabetes,(1) but it has been shown that increased physical activity substantially reduces the risk,(2) and participation in regular physical activity is one of the major recommendations of the evidence based guidelines for the primary prevention of diseases.(1) 

A consecutive number is then allocated to each source as it is referred to for the first time. This number becomes the unique identifier of that source and is re-used each time that particular reference is cited in the text.

Use Arabic numerals within parentheses, outside full stops and commas, but inside colons and semicolons. 

When multiple references are cited at the same place in the text, use commas without spaces to separate non-inclusive numbers.

            Example:  Multiple studies have indicated…(1,3,5,10) 

If multiple references cited at the same place in the text are inclusive, use a hyphen to join the first and last numbers.

            Example:  Multiple studies have indicated that…(1-3) 

Note on author/editor names

Examples with author names in the text of the document:

One author: Doe(7) reported on the survey...

Two authors: Avery and Williams(5) research demonstrates...

More than two authors, or authors and a group: include the first author’s surname followed by “et al.” or “and others”:

Doe et al.(9) reported on the survey....

Note: Do not use the possessive form 'et al's' - rephrase the sentence.

The reference list 

Every source which has an in-text citation should also be listed in the reference list at the end of your document. Reference list entries contain all the information that someone needs to follow up your source.

References are listed numerically at the end of the body of work. Agreed abbreviations for journal titles must be used and can be searched for from the National Library of Medicine's (US) PubMed website within their NLM catalog: Journals referenced in the NCBI database. 

If using EndNote you can install the Medicine Journal Terms List, which will includes over 14,000 journal title abbreviations. 

Note on author/editor names

Citing Medicine states that all authors (regardless of the number) should be listed, but notes that if space is a consideration, the number of authors may be limited to a specific number, such as the first three authors or the first six authors. The last named author is then followed with a comma and "et al." or "and others".  

One to six authors/editors : List all in the reference list:

1. Avery M, Williams F. The importance of pharmacist providing patient education in oncology. J Pharm Pract [Internet]. 2015 [cited 2016 Jan 27];28(1):26-30. Available from: https://journals-sagepub-com.ezproxy.library.uwa.edu.au/doi/10.1177/0897190014562382

More than six authors/editors: List the first six authors/editors then et al.:

2. de Lima M, McNiece I, Robinson SN, Munsell M, Eapen M, Horowitz M, et al. Cord-blood engraftment with ex vivo mesenchymal-cell coculture. N Engl J Med.[Internet]. 2012;367(24):2305-15. Available from: https://www-nejm-org.ezproxy.library.uwa.edu.au/doi/full/10.1056/NEJMoa1207285

No author or editor: List the title first:

3. Prevention strategies for asthma: secondary prevention. CMAJ [Internet]. 2005 [cited 2016 Feb 3];173(6) Suppl:s25-7. Available from: http://www.cmaj.ca/cgi/content/full/ 173/6_suppl/S25

Note on electronic resources 

All electronically sourced formats must include details of the type of medium, [Internet], and the date the material was cited, together with the full web address or DOI address.  

In the Vancouver examples section of this library guide there is an EndNote column which specifies the relevant fields and information to add for various material types. Hover over the 'Vancouver Examples' tab to see a drop down of different materials.