In Vancouver style, citations are numbered sequentially in the order they appear in the text. Numbers are placed in parentheses or as superscripts.

Example: 
Chronic diseases, such as hypertension and diabetes, are leading causes of mortality worldwide (1). Evidence suggests that lifestyle interventions can significantly reduce the burden of these diseases (2,3).

Reference list example:
At the end of the document, a numbered list of references is included, corresponding to the numbers used in the text. Medical journals often abbreviate journal names based on PubMed standards.

References:

1. GBD 2019 Diseases and Injuries Collaborators. Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020 Oct 17;396(10258):1204–22. 
2. Ezzati M, Riboli E. Behavioral and dietary risk factors for noncommunicable diseases. N Engl J Med. 2013 Sep 5;369(10):954–64. 
3. Estruch R, Ros E, Salas-Salvadó J, Covas MI, Corella D, Arós F, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013 Apr 4;368(14):1279–90.Author Names: Surname followed by initials without periods or spaces. Up to six authors are listed; if more, add “et al.”

1. Article Titles: Only the first word and proper nouns are capitalized.
2. Journal Titles: Abbreviated as per PubMed standards, italicized, or not depending on the journal style.
3. Dates: Include year, month, and day (if applicable).
4. Page Numbers: Use a concise range (e.g., 1204–22, not 1204–1222).