After several years of working as an editor using the Chicago Manual of Style almost exclusively, I found myself interviewing for a job at JAMA Network. Naturally, I wanted to prepare by learning as much as I could about AMA style. Google searches such as “Chicago vs AMA style” produced little in the way of useful information. Luckily, the AMA Manual of Style offers a free trial subscription option. Poking around here and there, I was able to glean some similarities and differences. But much of what I really needed to know I learned once I started my new job. What follows are some of my thoughts on making the switch from “Chicago style” to AMA.
First, the good news: we’re a lot more alike than we are different! All the wonderful stuff you know and love from CMOS or other guides about matters like subject-verb agreement, parallel construction, misplaced modifiers, and the like are just the same in AMA. Even our much-beloved serial comma retains its place of honor. We’re literally all speaking the same language!
Of course, there are also differences. Many of them are relatively minor, but they take a while to get used to. For example, unlike CMOS, AMA almost never uses periods after abbreviations. “Dr” still looks underdressed to me, even after several months. In a similar vein, while Chicago style advises spelling out numbers 1 to 100 (while acknowledging the alternative rule of spelling out 1-10 and using numerals for anything larger), AMA prefers the use of numerals in nearly every context, the main exception being the beginning of a sentence (CMOS concurs on this point). One habit I’ve had to break is using an en-dash to express ranges of numbers, whereas AMA prefers a hyphen or the word “to,” depending on the context (hyphens are for ranges in tables or in parenthetical expressions). While I generally do prefer a word over a symbol in formal writing, I miss seeing the en-dash around. It’s also strange not to see commas separating the digits of larger numbers—instead AMA keeps 4-digit numbers closed up, and for larger numbers opts for a thin space, a character Chicago rarely uses.
The formatting of references is an obvious point of difference, especially for a journal copyeditor like myself. In my job at JAMA Network, I get to use software with a reference editing component. If you’ve ever spent hours hand-styling journal references, you know what an exciting development this is. Chicago offers 2 systems of source citation, notes and bibliography and author-date references. In AMA style, references are cited in-text with superscript numerals corresponding to a reference list at the end of the article. The style of reference items is generally sparer than in Chicago, with initials for authors’ given names, lowercased article titles, and parsimonious use of punctuation and spacing. It’s a clean style that delivers the necessary information in the most efficient way possible.
My absolute favorite thing about working in AMA style is having a resource developed specifically for the type of content I’m editing. Anyone who’s ever tried to apply the more general Chicago style to a technical or scientific discipline knows that it leaves many questions unanswered. Often these topics will be covered in a house stylebook, but these aren’t always kept current and may not always have the information you’re looking for. Like CMOS, AMA has a guide to correct and preferred usage. But in addition to old standbys like effect vs affect, you’ll also find explanations of why cases are “managed” but patients are “treated.” In my experience, the discipline-specific language of medical editing and the structure of articles have been the 2 major lessons. Luckily, the AMA Manual of Style has you covered on both counts.
If you’re just starting out in the world of AMA style, there are some helpful resources you may want to check out. The quiz section of the style guide’s website has quizzes on a wide range of topics. You can test your acumen (or if you don’t mind spoilers, page through the answers in order to discern major points of the style). If you’re interested in more guided instruction, a medical editing class may be worth looking into. However you go about it, enjoy the learning process, and when in doubt, look it up!—Heather Green
Congratulations for joining the AMA stylists! I hope you can use your CMOS expertise to help your new colleagues apply en dashes with greater regularity and precision, eg, in page ranges and complex compounds.
‘AMA almost never uses periods after abbreviations. “Dr” still looks underdressed to me, even after several months.’
— Closer to UK style, which treats Dr and Mr as “contractions” (a subset of abbreviations in which both the short version and the long version retain their first and last letters in the same positions, so no dot in Dept and Ltd but a dot after Prof.). However, AMA, to my mind, takes this to the extreme, deleting the dot even after al in et al.
‘with initials for authors’ given names, lowercased article titles, and parsimonious use of punctuation and spacing.’
— closer to the style in the physical and biological sciences generally.
‘AMA keeps 4-digit numbers closed up, and for larger numbers opts for a thin space’
—again, this is standard UK practice and was also the style recommended in Scientific Style and Format (published by the Council of Science Editors, USA), which now suggests commas instead of thin spaces.
This was very helpful. Thank you!
I too was looking for “Chicago vs. AMA style” and coming up empty. Thanks for the intro!
Thank you for this. I’ve been working with CMOS and CSE for years now and I’m about to interview for a job that uses AMA. I wanted a quick overview of some differences so I don’t feel completely incompetent in the interview. This was perfect.