Back to: Search and Screen Your Studies

What is boolean logic? This is just a fancy way of describing what happens when you connect your terms with “AND” and “OR” and occasionally, “NOT” to create a custom search string. For a systematic review, the simplest way of doing this is to plug your specific PICO (D) elements and their synonyms into a formula like this:

(population synonym 1 OR population synonym 2 OR etc….)

AND

(intervention synonym 1 OR intervention synonym 2 OR etc….)

In some cases, you might also add:

AND

(terms for outcomes, study design, timing etc.)

How do you include your comparators in your search? You have a few options. You can include the comparator in the string of “ORs” with the intervention:

(population synonym 1 OR population synonym 2 OR etc….)

AND

(intervention synonym 1 OR intervention synonym 2 OR comparator synonym 1 OR comparator synonym 2 OR etc ……)

Or, you can create a separate search group for comparators and link that group to the rest of the search using “AND.” This would be the case if you are only interested in certain specific comparisons.

(population synonym 1 OR population synonym 2 OR etc….)

AND

(intervention synonym 1 OR intervention synonym 2 OR etc….)

AND

(comparator synonym 1 OR comparator synonym 2 OR etc ….)

Your approach will depend on your specific questions.