Use boolean operators to combine searches, for example, to complete a search concept by combining MeSH terms with searches for words in the title and abstract ([tiab] searches).
OR
Use OR to find publications that match one or both search terms. OR is used to widen your search (OR=mORe).
Example: diabetes mellitus[mesh] OR diabetes[tiab]
AND
Use AND to find publications that match both search terms.
When looking for articles on gene therapy for diabetes, use:
diabetes mellitus[mesh] AND genetic therapy[mesh] or even better:
(diabetes mellitus[mesh] OR diabetes[tiab]) AND (genetic therapy[mesh] OR gene therapy[tiab]).
When combining AND and OR, make sure that the ( ) are correctly placed. Searching with (diabetes mellitus[mesh] OR (diabetes[tiab] AND genetic therapy[mesh]) OR gene therapy[tiab]) gives a very different result...
NOT
With NOT all publications that match a certain term are excluded.
If you are looking for articles on diabetes, but not gestational diabetes, you could enter: diabetes mellitus[mesh] NOT gestational diabetes[mesh].
Note that articles on both types of diabetes will also be excluded.
Use Advanced Search to combine different building blocks.
You can use Advanced Search to create a complete query, but it is far more convenient to use a Word document (your logbook) to develop your building blocks. Every aspect of your query is assigned a building block with MeSH and tiab terms. You can easily combine these building blocks in the Advanced Search Builder.
Copy and paste the Search History from PubMed into your logbook.
For example:
'Nesting' involves placing multiple terms in round brackets (parentheses). This must be done if both AND and OR are used in a single query. For example:
cva[tiab] OR cvd[tiab] OR (cerebrovascular[tiab] AND accident*[tiab]) OR (cerebrovascular[tiab] AND incident*[tiab])