AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020

Authors
References

In reference lists, use the author’s surname followed by initials without periods. In listed references, the names of all authors should be given unless there are more than 6, in which case the names of the first 3 authors are used followed by “et al.” Note: The guidelines in Citing Medicine⁵ do not limit the number of authors listed in a MEDLINE/PubMed citation record, but, for space considerations, many journals truncate the list of authors’ names in references and online bylines (but often with the ability to expand to view the full list).

Note spacing and punctuation. Do not use and between names. Roman numerals and abbreviations for Junior (Jr) and Senior (Sr) follow authors’ initials. Note: Although NLM uses “2nd,” “3rd,” and “4th,” the JAMA Network journals prefer II, III, and IV, unless the author prefers arabic numerals.

When mentioned in the text, only surnames of authors are used. For a 2-author reference, list both surnames; for references with more than 2 authors or authors and a group, include the first author’s surname followed by “et al,” “and coauthors,” or “and colleagues.”

Doe⁷ reported on the survey.

Doe and Roe⁸ reported on the survey.

Doe et al⁹ reported on the survey.

Note: Do not use the possessive form et al’s; rephrase the sentence.

“Doe et al’s⁹ data support our findings.” should be changed to “The data in the study by Doe et al⁹ support our findings.”

In shorter nonresearch and nonclinical articles (eg, opinion pieces, book reviews, historical features, letters to the editor), the author’s first name or honorific may be used at first mention:

We agree with Dr Tayeb that the prevalence of domestic violence is difficult to determine.

In Growing Up Fast, Joanna Lipper profiles 6 teenaged mothers living in Pittsfield, Massachusetts, at the turn of the 21st century.

3.7.1 Group Authors.

Although the JAMA Network journals and many other journals make a distinction between a group of individuals writing for a group and a group of individuals writing as a group or in addition to (ie, and) a group in bylines, this distinction is not retained in the NLM database and is not displayed in MEDLINE/PubMed citation records (see 5.1.9, Authorship Responsibility, Group and Collaborative Authorship). The following examples show this difference in byline presentation.

Journal website:

PubMed citation record:

Therefore, references should use the individuals named and the group name without for or and. Note that the group name is preceded by a semicolon rather than a comma (to show, as noted in 3.1, References, Reference Style and Recommendations, that the information that follows is related to what precedes it but somehow distinct) and that articles (eg, the) in the group name are removed.

3.7.2 Group Author Names With or Without Individually Named Authors in the Byline.

Reference may be made to material that was authored by a committee or other group or that has no named author (see 5.1.9, Authorship Responsibility, Group and Collaborative Authorship). The following forms are used:

1.Writing Committee for the Diabetic Retinopathy Clinical Research Network. Panretinal photocoagulation vs intravitreous ranibizumab for proliferative diabetic retinopathy. JAMA. 2015;314(20):2137-2146. doi:10.1001/jama.2015.15217

2.World Medical Association. World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. JAMA. 2013;310(20):2191-2194. doi:10.1001/jama. 2013.281053

3.Global Burden of Disease Cancer Collaboration. The global burden of cancer 2013. JAMA Oncol. 2015;1(4):505-527. doi:10.1001/jamaoncol. 2015.0735

References may also have bylines that contain the names of individuals and the name of a group or several groups (see 5.1.9, Authorship Responsibility, Group and Collaborative Authorship).

4.Guggenheim JA, Williams C; UK Biobank Eye and Vision Consortium. Role of educational exposure in the association between myopia and birth order. JAMA Ophthalmol. 2015;133(12):1408-1414. doi:10.1001/jamaophthalmol.2015.3556

5.Taylor Z, Nolan CM, Blumberg HM; American Thoracic Society; Centers for Disease Control and Prevention; Infectious Diseases Society of America. Controlling tuberculosis in the United States: recommendations from the American Thoracic Society, CDC, and the Infectious Diseases Society of America. MMWR Recomm Rep. 2005;54(RR-12):1-81.

In examples 4 and 5 above, a semicolon, not a comma, precedes the group name in the author field and no articles (eg, the) are included with the group names.

In certain instances, an article may not have an author. In other instances, the author may remain anonymous (see 5.1.9, Authorship Responsibility, Group and Collaborative Authorship). However, the word “Anonymous” should not be used in a reference unless that word was published in the article’s byline. Note: There is no need to repeat the word “Anonymous” to represent a first name and a surname.

6.Anonymous. Care can’t get better until complaints are heard. BMJ. 2012;345:e4511. doi:10.1136/bmj.e4511

7.Incorrect percentages in the abstract. JAMA Oncol. 2017;3(12):1742. doi:10.1001/jamaoncol.2017.4368