Description of the change: Advice on hyphenation of 'co' changed: hyphens can now be used when the word following starts with a vowel. Well established words such as 'coincidence' should not be hyphenated.
Advice on hyphenation of 'mid' added: hyphens should be used for all words that have 'mid-' as a prefix, except for common words that are never hyphenated (e.g. midnight)
Description of the change: 7 December 2018: Added correct wording for GRADE levels of evidence (for both 'certainty' and 'quality').
19 September 2019: Added 'co-author'.
19 September 2019: Adjusted correct terminology for 'controlled before-after studies'.
19 September 2019: Added 'ROBINS-I'