The current format of the Cochrane Style Manual was launched in July 2016, replacing the Cochrane Style Guide, which was published as a PDF document and updated intermittently until October 2010. The Cochrane Style Guide was originally developed by the participants of project called the 'Prospective copy edit pilot', that was approved for use within Cochrane on 6 December 2002.

On this page we list the substantive edits and changes that were made to the Style Manual in its July 2016 version compared with its previous major edition (i.e. Cochrane Style Guide 4.1 edition; October 2010). For changes made since July 2016, a list of latest changes is continuously updated.

Changes to between Style Guide version 4.1 and July 2016 edition of Style Manual

General changes

• Moved from a static PDF version to a dynamic online version
• Name changed from ‘Cochrane Style Guide’ to ‘Cochrane Style Manual’
• Chapters organized thematically rather than alphabetically
• Chapters organized into smaller units with more links
• Table of contents giving a visual overview of the Style Manual
• Addition of information about how users may give feedback via ideas.cochrane.org

Abbreviations and acronyms

When to use abbreviations and acronyms

• New guidance on usage of abbreviations: use only if the term has three or more words; use if the term is used frequently in a section or in the review, or if the abbreviation or acronym is more familiar than the full name
• New guidance on redefining abbreviations and acronyms in the 'Abstract', 'Plain language summary', 'Main text', and 'Authors' conclusions' sections of reviews, and in the legends of tables or figures
• New guidance on the use of abbreviations in titles and headings
• New guidance permitting the use of abbreviations at the start of sentences

Common abbreviations

• New guidance on common abbreviations that do not need to be defined
• New guidance on formatting of 'i.e.', 'e.g.' and 'etc.': always use internal full stops and do not follow with a comma

Abbreviations to avoid

• New section on avoiding Latin abbreviations for dosing and some other abbreviations

Cochrane Review specific

Abstracts

• New brief guidance on abstracts, with links for further information

Headings

• Revised guidance on the use of predefined headings and drop-down heading styles

Search methods

• Updated and expanded section on how to describe search sources and search dates

Formatting

Italics

• Updated section with examples to illustrate how to present species names in an abbreviated form after their first mention

Ligatures

• New guidance about avoiding the use of ligatures (e.g. æ, œ, ß, ff)

Lists

• New examples added to section on formatting of lists

Paragraph break

• New guidance that soft returns are recommended in footnotes

Symbols and special characters

• New guidance about how to access special characters in Review Manager (RevMan) 5

Grammar and writing style

Active and passive voice

• Expanded section on the use of active and passive voice

Adjectives as nouns (new section)

• New guidance to avoid the use of adjectives (e.g. overweight) as nouns

And/or

• Guidance changed to allow 'and/or' in cases where reformulation would be awkward

Compared to/compared with

• New section outlining the potential difference in meaning between 'compared to' and 'compared with', and guidance that a distinction between these is not needed in Cochrane Reviews

Prefixes

• New guidance for the prefixes 'micro' and 'self'

Punctuation

• Expanded section includes the use of square brackets (used in chemical and mathematical formulae and in edits or comments on quotations) and presentation of quotations

Simple and accessible English

• New section about the importance of readability in Cochrane Reviews, with examples and links to other resources

Tautology

• Expanded section with more examples

Verbs: single or plural

• Expanded section with more specific guidance about group and plural nouns (e.g. data) and the verb forms they should take

International considerations

English Language: regional differences

• Guidance added about the use of '-ise' and '-ize' word endings, with reference to the Cochrane brand guidelines

Country names

• New section with guidance about how to refer to countries and regions in Cochrane Reviews and protocols

Ethnic group names

• New section with guidance about how to describe ethnic groups

Names and common terms

Common terms

• Expanded guidance on usage of common terms (e.g. 'double-blind', 'dropout' (noun), 'drop out' (verb), 'postoperative') and the terms 'participant', 'patient' and 'person'

Names

• Section updated to reflect branding changes and add further examples and resources
• New guidance on frequently used names
• Expanded guidance on family names, including formatting of designation of rank within a family, such as 'Jr' or '3rd'
• New guidance on virus names
• New guidance on pharmaceutical drug names and trademark symbols

Numbers, statistics, and units

Numbers

• Guidance expanded and reorganized with additional examples and minor corrections
• New guidance on number hyphenation (when written as words - not as numerals - in text)
• New guidance about the use of the terms million, billion, and trillion

Statistical and mathematical presentation

• New or updated guidance on use and presentation of P values, decimal places, equals and other signs, and summary statistics

Units and systems of measurement

• Expanded guidance on commonly used units (e.g. added microgram (µg), guidance on second as a unit of time and as an angle measurement)
• New guidance that the abbreviation L (not l) should be used for litre (also applies to mL, nL, etc.)
• New guidance for use of units as modifiers before a noun: write out the name of the metric quantity and use a hyphen between the numeral and unit, e.g. a 20-liter container

References

• Guidance has been adapted to correspond where possible with the referencing style of the National Library of Medicine (NLM)'s Citing Medicine, so that authors have an external resource to consult when particular cases are not covered by the Style Manual.
• New section on differences between Cochrane and NLM style
• New guidance on references entered in the Cochrane Register of Studies (CRS)

Citing references

• New guidance on: citing references in chronological order (cite from the earliest to the latest date); how to include multiple citations that refer to separate items of information; and avoiding using 'et al' in the text (only for use in references)

Reference fields

• New guidance:
  • Enter up to six authors into references in RevMan but enter all authors (where possible) when importing a reference into the CRS
  • Use a comma before 'et al'.
  • Italics should not be used in article or book titles, or for species names
  • Journal titles should be picked from the journal pick list
  • Exclude ‘The’ at the beginning of journal titles (e.g. 'The Lancet' should be inserted as 'Lancet')
  • Inclusion of digital object identifiers (DOIs)

Journal articles

• Expanded guidance adapted in the light of general changes
• Strengthened recommendation to include a DOI for journal articles in press.
• New guidance to use paretheses around 'in press'.

Cochrane publications

• Section expanded with new examples and updates in line with recent changes to Cochrane publications and minor changes to bring Cochrane publications more in line with other publications
• New guidance on best practice for citing the Cochrane Handbook for Systematic Reviews of Interventions
• New guidance on how to cite the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy and its chapters

Conference proceedings

• Section updated with new examples
• New guidance on how to complete each field when entering references
• New guidance for conference proceedings as journal supplements and conference abstracts in a journal supplement

Other reference types

• Section updated with new examples
• New guidance on citing GRADEpro GDT
• Guidance on citing maps and newspaper articles removed
• New guidance on how to reference figures, tables or appendices from an article (e.g. for reuse in Cochrane Reviews)

Differences between Cochrane and NLM style

• New section explaining differences between Cochrane style and NLM's Citing Medicine, including information on some frequently occurring issues in referencing: websites without titles; missing page numbers; changes in journal names; ambiguities with authors' names and surnames; references with errata or articles that have been retracted; discontinuous page numbering; dates crossing months in conference proceedings

Tables and figures

Tables in Cochrane Reviews

• New guidance on formatting body text in tables, including the use of numerals (instead of words) and full stops (used to end blocks of text only if the block ends with a full sentence)
• Expanded guidance on footnotes, providing clarification and examples

About this manual

• New sections on how to use the manual, how the manual is updated, and who contributed to its development