Question:  Why do some Embase subject terms have a + after them?

These particular terms are known as “Candidate terms”

Candidate terms are defined as terms under consideration for being added to the Embase (Emtree) thesaurus.

They are displayed and searchable with the same field code as other Emtree terms

Candidate terms do not appear in the Embase thesaurus and you cannot use the Explode function with them. However, candidate terms are reviewed annually; they may be promoted to bona fide Emtree terms or they may remain as candidates.

 If promoted to Emtree status, they will be searchable with Explode from the date of their promotion – it is possible therefore that you will find older records where they are indicated as candidates and newer ones where they are full thesaurus terms.

 For candidate drug terms, the term ‘Unclassified drug’ is also indexed into a record and can be used as a search term.


Will retrieve records containing the following candidate drug terms:

AAAS protein + 
AMRH2 protein + 
HOXC protein + 
RARG protein + 

Candidate terms appear in the Subject field of Embase records with a following ‘+’ sign,
e.g. morihepamin+