A systematic review needs a systematic search strategy that attempts to identify all studies that meet the eligibility criteria. 

Step 1 - Formulate your question and translate it into a search strategy.

Step 2 - Identify the key concepts of your question. The frameworks used to develop your question are a good start.

This search strategy planner can also help you map out your key concepts and formulate your search.

Step 3 - Develop search terms based on your key concepts. The compose a search guide demonstrates how to compose a search and use it on a sample of library databases.

The guide covers the processes involved in composing a search using                                                                    

• Keyword searching
• Database syntax
• Subject heading searching
• Boolean logic

The following is a brief overview of search strategies from the compose a search guide that are most useful when conducting a systematic review.

Keyword searching is the most common form of searching. It involves using key terms and phrases to identify individual results that contain those terms in the main fields (such as title and abstract) of their record in the database.

As different authors may use different terminology, it is important to consider all relevant synonyms and alternate terms for your concept to ensure you are finding all relevant results on your topic.

Think about:

• Medical vs common terms eg. Varicella Zoster vs Chicken pox
• Acronyms and abbreviations eg. COPD vs Chronic obstructive pulmonary disease
• Generic vs Brand names eg. Acetaminophen vs Panadol
• English vs American terminology eg. Tumour vs Tumor
• Broader vs narrower terms eg. Obesity surgery vs Bariatric surgery

Subject headings are a set of controlled terms that describe specific concepts in a database.

For systematic searching, it is important to search both keywords and subject headings.

This is to ensure you have conducted a comprehensive search and identified as many relevant articles as possible.

If you only use keywords in your search strategy, you could miss articles if not all relevant terms are in your search.

If you only use subject headings in your search strategy, you could miss articles that have not been indexed or have older indexing.

Things to know about subject headings in databases:

• Not every database uses subject headings
• Each database may have their own subject headings that do not translate to other databases.
• Use the 'help' menu in a database to determine how to use subject headings in your search for a particular database.

The advantage of using subject headings

• Are consistent across all records in a database on the same topic
• Identifies the key concept regardless of the phrasing or terminology used in-text by the author
• Compiled into a searchable thesaurus

For more information on why subject headings and keyword searches should be used together:

Solomons, T., & Hinton, E. (2021). Federated searches: why a one-stop shop approach to literature searching falls short for evidence synthesis. JBI Evidence Synthesis, 19(6), 1259-1262. https://doi.org/10.11124/JBIES-21-00177

This webinar recording covers:

• Types of reviews & definition of systematic reviews
• Checking for prior reviews
• Search strategy planning, keywords and subject headings
• Where to search
• Boolean Operators AND & OR, Truncation & Wildcard searching
• Grey literature
• Managing search results in EndNote & Covidence
• PRISMA reporting standards