Systematic searching

Systematic Searching

Systematic searching is a process of searching and combining Subject Headings (index words), when available, and keywords for each concept and combining these concepts to retrieve results.

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 recommended for searching and arranged in a hierarchical structure, showing 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 using search engines like Google and Library Search.
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 and will generally retrieve more results but may include more irrelevant results.

Systematic search - Video tutorials

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)

Systematic search steps

PICO search strategy
POPULATION / PROBLEM CONCEPT 1	INTERVENTION CONCEPT 2	COMPARISON CONCEPT 3	OUTCOME CONCEPT 4
"attention deficit hyperactiv* disorder* OR ADHD OR "attention deficit disorder with hyperactiv*" OR ADDH	"cognitive behav* therap*" OR CBT	"family based therap*" OR FBT

Note: Searching is iterative, your search strategy will change as you work through the systematic search process.

Step 1 – Search your P or first concept via the subject heading method:
•   Type in Attention Deficit Hyperactivity Disorder (with ‘map to subject heading’ ticked and without searching tips/syntax)
•   Select Attention Deficit Disorder with Hyperactivity (or any others if they apply) – have a look at the Scope for definition and more PICO map terms if available and include in your search strategy.
•   Select Explode & select Include all subheadings - click on continue
•   If the aspect you are looking for is not in the subject headings – search via keywords method only
•   Click on Search History to display search:

Step 2 – Search your P or first concept via the keyword method:
• type all the keywords from your P or first concept, one search at at a time using truncation * for alternate endings and quotations “ ” e.g. "attention deficit hyperactiv* disorder*". Make sure ‘map to subject heading’ is unticked.

Step 3 – Select and combine all searches for P or your first concept into one set
• Combine searches with OR

Step 4 – Search your I or second concept via the subject heading method:
•   Type in Cognitive Behavior Therapy (with ‘map to subject heading’ ticked)
•   Select Cognitive Behavioral Therapy (or any others if they apply) – have a look at the Scope for definition and more PICO map terms.
•   Select Explode & select Include all subheadings - click on continue
•   If the aspect you are looking for is not in the subject headings – search via keywords method only

Step 5 – Search your I or second concept via the keyword method:
• Type all the keywords from your I or first concept, one search at a time using truncation * for alternate endings and quotations “ ” e.g. "cognitive behav* therap*". Make sure ‘map to subject heading’ is unticked.

Step 6 – Combine searches for your I or second concept into one set
• Combine searches with OR

Step 7 – Search your C or third concept via the subject heading method:
•   Type in Family Based Therapy (with ‘map to subject heading’ ticked)
•   Select Family Therapy (or any others if they apply) – have a look at the Scope for definition and more PICO map terms.
•   Select Explode & select Include all subheadings - click on continue
•   If the aspect you are looking for is not in the subject headings – search via keywords method only

Step 8 – Search your C or third concept via the keyword method:
• Type all the keywords from your C or third concept, one search at at a time using truncation * for alternate endings and quotations “ ” e.g. "family based therap*". Make sure ‘map to subject heading’ is unticked.

Step 9 - Select the search number of the final results for each concept and click ‘And’:

View an example of this search in MEDLINE. Select 'Advanced' and 'Continue to site' if you receive a security warning.