Manuscripts undergo thorough copyediting after acceptance and our copyeditors will ensure tables are formatted correctly. However, we have outlined below general guidelines for formatting tables and specific house style for authors' reference.
Tables are meant to visually display and organize information using columns and rows. Each table should be numbered consecutively, placed close to its first mention in the text, and have a descriptive caption.
Excerpt from the AMA Manual of Style:
For a table to have maximum effectiveness, the information it contains must be arranged logically and clearly so that the reader can quickly understand the key point and find the specific data of interest. Information in tables should be organized into columns and rows by type and category, thereby simplifying access and display of data and information.
During the planning and creation of a table, the author should consider the primary comparisons of interest. Because the English language is read first horizontally (from left to right) and then vertically (from top to bottom), the primary comparisons should be shown horizontally across the table. Data that depict cause-and-effect or before-and-after relationships should be arranged from left to right if space allows or, alternatively, from top to bottom. Information being compared (such as numerical data) should be juxtaposed within adjacent rows or adjacent columns to facilitate comparisons among items of interest.
Although tables frequently are used to present many quantitative values, authors should remember that tabulating all collected study data is unnecessary and actually may distract and overwhelm the reader. Data presented in a table should be pertinent and meaningful.
The length of the table should also be considered. For ease of reading and practical reasons, a table that would span horizontally or run vertically onto a second page should, if possible, be recast into 2 or more smaller tables.*
AMA Manual of Style Committee. 4.1.2. Organizing Information in Tables. AMA Manual of Style: A Guide for Authors and Editors (10th Edition). 2009 April. URL: http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-97#
*For most paper types, we accept tables that are maximum 1.5 pages in length. For systematic reviews, we permit tables >1.5 pages because these tables often contain data critical to the meaning of the paper.
Presentation, placement, and orientation
Tables need to be included within the manuscript’s Microsoft Word file. Tables will not be accepted as an image file; if uploaded as images authors will be asked to provide a new manuscript document with tables included before copyediting will commence. Only upload tables as separate files if they are intended to be an appendix (see How to/add upload a Multimedia Appendix?).
Each table is placed after, but as close as possible to, its first mention in the manuscript file.
Do not format tables on a landscape page and do not use smaller font. Tables are typeset in portrait orientation and in the same font as the rest of the manuscript. If landscape orientation or smaller font are necessary to fit all of the columns, the text will appear squished in the final PDF. If this is the case, this table might be better uploaded as a multimedia appendix.
You may be asked during copyediting or proofreading to move table content to a Multimedia Appendix if the table will appear more than 1.5 pages long in the final typeset PDF (exceptions for Systematic Reviews). This is generally non-negotiable.
Each table requires a brief description that summarizes the topic of the table succinctly. Background information or interpretation of the data in the table do not belong in caption and should instead be placed in the body of the manuscript.
Do not use a soft line break within a table cell to separate different categories/subcategories. For each new row of information, create a new table row rather than using line breaks (ie, pressing “Enter” within a cell).
Values for sample sizes and percents should be presented in the same column as "n (%)". Column totals should be added to the header rather than featured in a final "Total" row.
Each column requires a heading that describes the information presented in that column. This heading should apply to all data in that column. The unit of measurement is usually presented in the column heading; however, if the unit differs for each row, the unit of measurement can be presented in the left-most column of the row (row heading). Units of measurement are separated from the column description with a comma. Column headings are written in sentence case.
Participants, n (%)
Control group (N=50), n (%)
The row headings are in the left-most column of the table. Each row requires a heading that describes the information presented in that row. This heading should apply to all data in that row. If units of measurements are not provided in the column heading, they should be placed in the row heading, separated from the row description with a comma. Row headings are written in sentence case.
Category headings are frequently used to group sets of variables (eg, race, income strata, and gender). Category headings must be in marked in bold. Copyeditors will ensure category rows are formatting correctly. However, if authors wish to format these according to our editorial style prior to submission, please follow these instructions:
- To preserve indenting, category headings and the subcategories are placed in separate columns
- The first column will contain the bolded category heading (eg, “Age (years), n (%)”). The subcategories will be placed in rows in the second column (eg, "13" and "14")
- Merge the cell containing the category heading with the cells to the right of it so the category heading spans the column(s) with the subcategories
Radovic A, McCarty CA, Katzman K, Richardson LP. Adolescents’ Perspectives on Using Technology for Health: Qualitative Study. JMIR Pediatr Parent 2018;1(1):e2. DOI: 10.2196/pediatrics.8677
- Footnotes are used to supply additional information for the entire table, a row, a column, a category, or a single data entry. The footnotes should appear in alphabetical order from left to right, top to bottom within the table
- All footnote symbols within a table are superscripted letters (a-z). The use of *, **, *** footnotes to mark significance levels (eg, P<.05, P<.01, P<.001) is discouraged. Authors are asked to provide exact P values instead. While we prefer the exact P values, there are exceptions to this general rule. The use of *, **, *** footnotes to indicate significance levels is allowed in the following instances:
- In tables of systematic reviews, which tend to be busy and where the original P values can't be found in the original publications
- When Odds Ratios instead of P values are presented
- If for any reason authors are unable to provide the exact P values
- Footnotes are placed in a list directly after the table. All footnotes presented in this list require a corresponding letter within the table
- Footnotes can be used for information such as abbreviations, P values, explanations for missing data, and missing information