In PubMed you can search the bibliographic information (author, title, year, journal, etc.) of articles by word or phrase. By entering a search term followed by a search field tag, PubMed searches for that particular term in the designated field.
|
diabetes[ti] |
|
diabetes[tiab] |
|
diabetes mellitus[mesh] |
PubMed only contains abstracts of articles, not full texts, so searching the entire article for words is not possible.
Similar to MeSH, the title and abstract are fields that provide information on the content of an article.
Often there are differences in how a concept is described by the authors and people that search for literature. If you only search with the field tag [tiab], you risk missing articles.
Compare the number of results for the following searches (click the links below):
The third example shows that over 61,000 articles contain the MeSH term ‘quality of life’ without the phrase ‘quality of life’ occurring in the title or abstract. Some of these 61,000 articles could be relevant to you, and you would miss out on them if you would only use the field tag [tiab] in your search strategy.
1) If the topic has a MeSH term, check the entry terms (See tab: MeSH) for relevant synonyms to add to your [tiab] search.2) Or do a simple subject search and check the Search Details (See tab: Introduction) for synonyms that PubMed may have included in the search.
Phrase
When looking for a particular phrase in PubMed (words in an exact order) use double quotation marks ("..."). Using quotation marks disables PubMed’s automatic term mapping function.
PubMed will also interpret search terms as a phrase when using a search field tag.
Compare the number of hits and search details (to view click the links below) of these searches:
Proximity Search
With a proximity search, you can search for multiple terms in context, regardless of the order of the words. To perform a proximity search in PubMed, use the following format: “term1 term2”[field:~N]. Replace N with the maximum number of words that can be between the terms. For example,“diabetes complications”[tiab:~3] retrieves results such as diabetes complications, diabetes-related complications, and complications in diabetes.
Proximity searches cannot be combined with wildcards. Consider the different word variations, such as singular and plural forms, when using proximity searches.
Wildcards
An asterisk (*) can be used to search for word variations in PubMed. By adding an asterix at the end of a word stem, PubMed will search for words that start with the word stem complemented with 0 to an infinite number of characters. Searching with microscop* will also search for: microscope, microscopes, microscopy, etc.
In a wildcard search, the asterisk can be placed in different parts of the word. Multiple wildcards can be used in a single term. For instance, searching for “spin* injur*” retrieves spine injury, spine injuries, spinal injury, and similar variations. You can also use wildcards within a word to account for variations, such as “tumo*r*” to retrieve tumor, tumors, tumour, and tumours.
Use of wildcards may cause unnecessary ‘noise’, for instance when undesirable word variations are included in the search. The word stem must contain at least four characters, so avoid searches like cel* or pre*
Example: If you use diet* to find word variations such as diets and dieting, be aware that you will also search for diethyl ether (an anesthetic) and all other drugs that start with diethyl.. To make the search more specific try to lengthen the root word or type out relevant word variations.
