Citation Styles in NLM Medical Referencing

If you are studying medicine or writing for a medical journal, you may be asked to use NLM referencing. But this system offers three different citation styles, so it’s important to know which approach to use. In this post, we outline the three systems available and how to cite sources in each.

Citation Styles in NLM Referencing

When people say ‘NLM referencing’, they’re referring to the citation style set out in Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers. This provides an in-depth guide for how to reference sources in medical writing according to the US National Library of Medicine.

The book outlines three citation styles for use in medical writing:

• Citation-sequence – This style uses numbered citations, with sources listed at the end of your document in the order they are first cited.
• Citation-name – Like the citation-sequence style, but with sources in the reference list organised alphabetically by author surname.
• Name-year – Uses bracketed in-text citations that include the author’s surname and the year of publication. Cited sources are then listed alphabetically by author surname in a reference list.

Due to this variation, you should always check which version your university or publisher prefers. And whichever system you use, make sure to apply it consistently throughout your writing. In the rest of this blog post, we’ll take a quick look at how to format the citation styles above.

Citation-Sequence Referencing

NLM’s citation-sequence referencing style is a version of Vancouver referencing. Essentially, this means that each citation number in the text points to a source in the reference list, like this:

The treatment was effective for 80% of patients.¹

All sources are numbered in the order they are first cited. The superscript ‘1’ at the end of the sentence above, for instance, would point to the first source in the reference list. If we were then to cite the same source again later, we would repeat the same number as on the first citation.

We’ve used a superscript number above as this is a common style for in-text citations. However, Citing Medicine does not specify a formatting style. As such, different schools and publishers may use different citation styles. We could also cite the source above in brackets, for example:

The treatment was effective for 80% of patients (1).

Make sure to check how your institution prefers to format citations.

Citation-Name Referencing

The only difference between citation-name referencing and citation-sequence referencing is that sources are organised by author surname in the former. For example, if we were to cite ‘Allen’ and ‘Smith’ in a paper, we would number them ‘1’ and ‘2’ respectively because ‘Allen’ comes before ‘Smith’ alphabetically. This applies even if we cite ‘Smith’ first:

Smith² has shown that regular exercise can prevent some serious medical conditions and relieve symptoms in others. However, Allen¹ has challenged Smith’s methods, so there is still some debate over the issue.

We’ve used superscript numbers again here. As above, though, remember to check how your university or publisher prefers to format in-text citations.

Name-Year Citations

NLM’s name-year citations are a version of Harvard referencing, where we give the author’s surname and a year of publication in brackets:

The treatment was effective for 80% of patients (Smith 2014).

Here, we show that we’re citing someone called ‘Smith’ and that the source was published in 2014. We would then give full publication information in the reference list at the end of the document.

Remember, too, that Proofed has expert academic proofreaders available, 24/7. So to make sure the referencing in your document is clear and consistent, submit a document for proofreading today.