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Evidence Based Practice: Step 4: Planning a search

Planning a search

An effective database search strategy is essential when searching for evidence based literature to answer clinical questions. Your search strategy should include both keywords and subject headings, as well as alternative search terms and advanced search syntax.

Keywords and subject headings

Literature in most health and medicine databases can be found using both keywords and subject headings. Searching with both keywords and subject headings will help you to find all relevant literature.

Watch this video to learn more about the differences between keywords and subject headings.

Alternative search terms

Including synonyms and alternative terms in your search will help you to find all relevant literature. This can include: 

  • words that are spelled differently overseas (e.g. paediatric and pediatric)
  • concepts that are referred to differently (e.g. physiotherapy and physical therapy)
  • conditions with both formal and informal names (e.g. heart attack and myocardial infarction), and
  • names that have changed over time (e.g. lumbago and lower back pain).

Advanced search syntax

Advanced search syntax, such as truncation and wildcards, can be used to improve the results of your database searches. Different databases use different operators for search syntax.

Search syntax can only be used for keyword searching, not with subject headings.

Building a search

After you have identified your keyword terms, subject headings, and applied search syntax you are ready to group and combine them together using Boolean operators.

The Boolean operator OR is used between alternative search terms for a concept. The database will find articles that mention any of these terms.

The Boolean operator AND is used between different concepts to combine them. The database will find articles containing an overlap of your concepts.


Step 3: Identify the study
designs that best 
answer the question


Limits and filters

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