When searching any database with ANDs and ORs together:Connect main concepts with AND as in the left side of the PubMed screenshot below.Put all synonym terms/concepts meaning the same thing or being compared together with OR in the same line and connect that line to the others with AND. Like this:
Two More Database ExamplesConnect main concepts with AND on separate lines. Put OR terms in same line.
Again! This is important:For PICO or other complex questions, use search builders with multiple lines like this. Main concepts are connected with AND. (P&I of PICO)Individual concepts with synonyms , spelling variations, or other terminology to capture the same concept should all be entered on the same line together with OR. (Spelling variations for the I of PICO on one line)
If you type these into the search box without parentheses, there are 693 bogus-looking results:knee osteoarthritis AND tai chi OR tai ji
By using the separate lines as we did, the database understands how to apply the Boolean, and you get 33 relevant resultsknee osteoarthritis AND (tai chi OR tai ji)