PubMed offers proximity searching. This is a technique which allows you to search for keywords within a specified number of words from each other. For example, you could search for "breast cancer" within five words of therapy.
Below you can both watch a video on building a proximity search in PubMed and review written directions.
Before building a proximity search, you will need to select your keywords. The following search structure is used to build a proximity search.
"search terms"[field:~N]
Using two or more keywords, placed into quotation marks, followed by the field you wish to search and the number of words (or N) between the keywords. PubMed allows for proximity searches in the Title and Title/Abstract fields. Note that there are no spaces in this search. With the following keywords: medical library instruction, a proximity search would look as follows:
"medical library instruction"[title/abstract:~10]
A proximity search can help narrow a search, particularly when there aren't MeSH terms available for a topic or a simple keyword search is retrieving a large results set. Look at the two example search results, one the proximity search above and the other a simple search.
MeSH stands for Medical Subject Headings. These are a form of controlled vocabulary used to organize articles and resources in databases.
MeSH Terms can be used to build searches in PubMed. Below are two videos from PubMed and the National Library of Medicine, and an documented example search using MeSH terms and Keywords.
Combining MeSH terms and keywords is used to ensure you're retrieving all possible articles on a topic. Keyword searches are popular and easy to build, plus they allow you to search newer articles that might not be index in Medline with MeSH terms. Whereas, searches using only MeSH terms are far more precise, but might miss out on the newest articles which have yet to be indexed.
After selecting keywords and searching for MeSH terms in the MeSH database, it's time to construct a search statement. Remember, these searches use Boolean (e.g., AND, OR), nesting, and often phrase searching.
"library instruction", "information literacy", "Library Services"[Mesh], "nursing education", "Education, Nursing"[Mesh]
("library instruction" OR "information literacy" OR "Library Services"[Mesh]) AND ("nursing education" OR "Education, Nursing"[Mesh])
Notice in the above search statement, using both keywords and MeSH terms, there is some repetition between the keywords and MeSH terms. This is to ensure articles not assigned a particular MeSH term are still found in the results. You can see the results list for the above search using the link below.