Structured (or systematic) searching

What is structured searching?

Structured searching, sometimes referred to as systematic searching, is an advanced method of searching within a database.

To search in this way, you use a combination of ‘subject headings’ and ‘keywords’.

Why search this way?

While this method of searching may seem more laborious, it’s important to conduct a thorough search of the literature in order to find the best available evidence for your patient or client.

What are subject headings & keywords?

The table below compares some of the differences between subject headings and keyword searching:

Subject headings Keywords

A fixed list of terms that are arranged in a hierarchical structure and show the relationships between terms. These are referred to differently depending on the database e.g. Medline uses MeSH (Medical Subject Headings) terms.

Natural language words that describe your topic. Keywords are used when searching Google.                                                                                                                      

Provides consistency in the description of the content of the articles.

Useful for searching for a specific term or phrase when there is not an appropriate subject heading.

Do not need to think of synonyms for your topic.

Useful for searching topics that use new concepts or terminology (subject headings take a while to be developed).
Less flexible to search by - need to know the exact controlled vocabulary term. More flexible to search by - can combine together in many ways.
Database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear.

Database looks for keywords anywhere in the record.

View these videos to find out more:

  • Part 1: Introduction to Databases; Developing Search Terms (Subject Headings vs. Keywords)       
  • Part 2: Search History; Combining Terms; Applying Limits;

Database Fundamentals Part 1 & Part 2. McMaster Health Sciences Library (YouTube)

Database tutorials

Learn advanced search techniques using both Subject Headings and key search terms. Click image below to access tutorial.

This type of searching is also applicable to Embase, PsycINFO & AMED although these databases use different Subject Heading systems with differing functionality.

Systematic search MEDLINE & CINAHL

Search tips

  • Use database limits to focus your search. Most will include language, gender, age, date or type of publication
  • Check the database 'Help' or 'Tips' for further information
  • Create a personal account and save your search
  • Refine your search as you go. You may pick up further subject headings and keywords to use from other database
  • See our Health Databases guide for further tips & online tutorials

How to create accounts and save your search

Use your own personal area (folder) to collect, store and export results. All the items you save to your personal folder remain in your folder until you remove them.

Save searches in the Cochrane Library for later use or further refinement.