Ovid databases

Subject headings are standard descriptions used by databases to help with searching.

• They help retrieve articles on a topic, even if different words are used in the text.
• The whole collection of subject headings is called a controlled vocabulary or thesaurus.
• Controlled vocabularies are an advantage of subject specific databases over general databases or google scholar.
• All Ovid databases have a controlled vocabulary.
   

Subject headings are arranged in a hierarchical structure, from the general to the specific.

Here is the hierarchy for the subject heading COVID-19.

Diseases

Infections

Pneumonia

Pneumonia, Viral

COVID-19

Instructions from Video: How to add influenza subject heading to your search

1. Type "influenza human" in the search box

2. Select tickbox Map Term to Subject Heading

   
   
    

3. Check the Scope Note for a definition and more information. (OPTIONAL)
   
   
4. Click on the Subject Heading link
   This will take you to the tree, which shows where your Subject Heading sits in the hierarchy.
5. Check if the Subject Heading is available to explode and if the narrower terms are relevant.
   Exploding selects all subject heading underneath the current one.
6. Click Continue
7. Select Subheadings to narrow your search (OPTIONAL)
8. Click Continue

Subject headings are arranged in a hierarchical structure, from the general to the specific.

Search for any relevant subject headings on the following topics:
 

Medline (MESH)

• Middle Ear Infection
• Gastroenteritis

Embase (EMTREE)

• Anti epileptic drugs
  Compare this with MESH, in particular the number of specific drugs that appear underneath the subject heading.

PsycInfo (APA Thesaurus)

• Antidepressant medication
• Trauma