Searching with PubMed and PsycINFO
Last update: 27 May 2011,
by Maureen Bell
This page will explain how to perform both simple, and more complex searches using PubMed and PsycINFO. General background information on PubMed and how it works is on a separate page.
Searching PubMed
Using Field Codes
Using MeSH
Tips and Tricks for PubMed
Searching PsycINFO
Using Field Codes
Using PsycINFO's thesaurus
Searching PubMed
Using Field Codes
When searching either PubMed or PsycINFO it's important to tell the database where to look for words - titles of articles, abstracts, or the indexing language of the database. To do this you need to use field codes.
PubMed has a wide range of field codes, but those you're most likely to use are:-
[mh] to search for Mesh terms
eg. cognitive therapy[mh]
[majr] to restrict your search to major (most important) indexing terms only
eg. cognitive therapy[majr]
[tiab] to search for words in titles and abstracts - this is essential for searching the most recent literature
eg. cognitive therap*[tiab]
PubbMed Search Using MeSH
PubMed has a thesaurus which is called MeSH - which is simply an acronym for Medical Subject Headings. Indexers are instructed to apply multiple MeSH terms to articles in the database, to reflect the subject content of the article. It is in this indexing that the greatest search power of PubMed lies. It is the ONLY database which will automatically search not only the MeSH term you choose, but all of its subcategories - this is known as "exploding" a term, and greatly simplifies more complex searching. If you chose to search the MeSH "mental disorders" a search would be performed on all mental disorders. If you scroll down the page you will see the full hierarchy of terms. Any other database would simply look for the words"mental disorders" and completely ignore articles on any specific diagnostic category.
You need to be aware that very recent material in PubMed will not be indexed with MeSH terms, and you will therefore need to search for words in titles or abstracts to retrieve this material. The labels on the individual entries will indicate this.
Very new material will be labelled either
(PubMed - as supplied by publisher)
or
(PubMed - in process)
and will not have indexing (MeSH) terms added to it.
Material which has MeSH indexing will be labelled
(PubMed - indexed for MEDLINE)
To see the indexing for an article that is labelled (PubMed - indexed for MEDLINE) click on the title of the article. This will display the article details, plus its abstract, and a link to enable you to view its MeSH Terms
Open two tabs or browser windows when searching PubMed - this will allow you to have MeSH open in one, and PubMed open in the other. That way it's easy to move between looking up terms and testing searches.
A simple MeSH search grid for systematic reviews of cognitive therapy for PTSD would look like this. There are three columns, as we are dealing with three separate concepts.
|
| Cognitive Therapy |
PTSD |
Systematic Reviews |
| cognitive therapy[mh] |
stress disorders, post-traumatic[mh] |
systematic[sb] |
and the search would be
cognitive therapy[mh] AND stress disorders, post-traumatic[mh] AND systematic[sb]
The last column appears very simple as it contains only systematic[sb]. Click here to see what's actually happening behind the scenes.
The problem with such a search is that it does not allow searching of the most recent (unindexed) articles - either [PubMed -in process] or [PubMed - supplied by publisher] Nor does it allow for indexer error, or differences in interpretation of content by different indexers.
To improve the search we need to add some further options. We'll omit the systematic reviews component as it's easy in PubMed just to add it once your search is complete.
| Cognitive Therapy |
PTSD |
Cognitive therapy[mh]
Cognitive therapy[tiab]
Cognitive behavior therapy[tiab
Cognitive behaviour therapy[tiab]
Cognitive behavioural therapy[tiab]
Cognitive behavioral therapy[tiab]
CBT[tiab] |
Stress disorders, post-traumatic[mh]
Post traumatic stress[tiab]
Posttraumatic stress[tiab]
Post-traumatic stress[tiab]
PTSD[tiab]
|
and the search would now be
Cognitive therapy[mh] OR Cognitive therapy[tiab] OR Cognitive behavior therapy[tiab] OR Cognitive behaviour therapy[tiab] OR Cognitive behavioural therapy[tiab] OR Cognitive behavioral therapy[tiab] OR CBT[tiab]
AND
Stress disorders, post-traumatic[mh] OR PTSD[tiab] OR Post traumatic stress[tiab] OR Posttraumatic stress[tiab] OR Post-traumatic stress[tiab]
Here is what a record of these two search strategies on PubMed would look like.
When you have finished collecting terms you are ready to search. PubMed requires that Boolean operators are in upper case, so it's important when searching PubMed to use AND, OR, NOT to connect your search terms. PubMed's tutorial gives a clear explanation of how Boolean logic works.
- Copy and paste the first set of terms into PubMed, and search
- Now copy and paste the second set of terms into PubMed, and search
- Click on Advanced search – above Search box
- Now combine the two searches using AND
Normally Boolean logic would require that you enclose each set of terms in parentheses to ensure that the logic worked properly, but performing them as separate searches in PubMed fulfills the same purpose, and ensures that each term in each set will be matched with each term in the other set when you combine them.
Tips and Tricks for PubMed
- Open two tabs or browser windows when searching PubMed - this will allow you to have MeSH open in one, and PubMed open in the other. That way it's easy to move between looking up terms and testing searches.
- Look in the Details box (right hand side of the search screen) to see how PubMed has interpreted your search
- Click on the Title of an article to see MeSH terms used to index it
- Expert Searching in PubMed
This is a single page guide produced by the Countway Library at Harvard University. Don't be put off by the "expert" - it's a very useful and easy to follow guide with lots of examples to help you to take advantage of PubMed's incredible search power.
Searching PsycINFO
Unfortunately the same search cannot be simply copied and pasted into another database. Although there may be many similarities, field names and abbreviations will be different, and the user interface will sometimes require a slightly different method.
Field Codes for PsycINFO
The codes you're most likely to use are:-
TI – Article title
AU – Author
AB - Abstract
DE – Exact Subject Heading
MJ - Word in Major Subject Heading
SO – Publication Name
PsycINFO also has a Thesaurus of indexing terms but they may be rather different from PubMed's MeSH terms. Unlike PubMed it does not automatically explode terms from its thesaurus - you have to instruct it to do so.
The method you use to search will be similar
First look up your terms in its Thesaurus. As you can see from the image below the PsycINFO terminology for PTSD is quite different from PubMed's.
and the PsycINFO Thesaurus allows searching not just of cognitive therapy, but specifically of cognitive behavior therapy
Allow for additional words in titles and abstracts, as you did in PubMed, to extend the range of your search. PsycINFO does not allow you to search titles and abstracts together so you need to do separate searches for terms in each field.
NOTE In PsycINFO, when searching for phrases in titles or abstracts you must use inverted commas to make sure the words are searched together as a phrase, not separately.
A simple grid for a search using PsycINFO Thesaurus terms only would look like this
| Cognitive Therapy |
PTSD |
DE cognitive behavior therapy
DE cognitive therapy |
DE posttraumatic stress disorder
DE traumatic neurosis
DE stress reactions |
and the search would be
DE posttraumatic stress disorder OR DE traumatic neurosis OR DE stress reactions
AND
DE cognitive behavior therapy OR DE cognitive therapy
To improve the search we need to add some further options to allow for indexer variability in interpretation of content
| Cognitive Therapy |
PTSD |
DE cognitive behavior therapy
DE cognitive therapy
TI “cognitive therapy”
AB “cognitive therapy”
TI “cognitive behavior therapy”
AB “cognitive behavior therapy”
TI “cognitive behaviour therapy”
AB “cognitive behaviour therapy”
TI “cognitive behavioural therapy”
AB “cognitive behavioural therapy”
TI “cognitive behavioral therapy”
AB “cognitive behavioral therapy”
TI CBT
AB CBT |
DE posttraumatic stress disorder
DE traumatic neurosis
DE stress reactions
TI PTSD
AB PTSD
TI “post traumatic stress”
AB “post traumatic stress”
TI “posttraumatic stress”
AB “posttraumatic stress”
TI “post-traumatic stress”
AB “post-traumatic stress”
TI “war neuros*”
AB “war neuros*”
TI “combat stress”
AB “combat stress”
TI “combat neuros*”
AB “combat neuros*”
TI “traumatic stress”
AB “traumatic stress”
TI”shell shock”
AB “shell shock” |
and the search would be
DE cognitive behavior therapy OR DE cognitive therapy OR TI “cognitive therapy” OR AB “cognitive therapy” OR TI “cognitive behavior therapy” OR AB “cognitive behavior therapy” OR TI “cognitive behaviour therapy” OR AB “cognitive behaviour therapy” OR TI “cognitive behavioural therapy” OR AB “cognitive behavioural therapy” OR TI “cognitive behavioral therapy” OR AB “cognitive behavioral therapy” OR TI CBT OR AB CBT
AND
DE posttraumatic stress disorder OR DE traumatic neurosis OR DE stress reactions OR TI PTSD OR AB PTSD OR TI “post traumatic stress” OR AB “post traumatic stress” OR TI “posttraumatic stress” OR AB “posttraumatic stress” OR TI “post-traumatic stress” OR AB “post-traumatic stress” OR TI “war neuros*” OR AB “war neuros*” OR TI “combat stress” OR AB “combat stress” OR TI “combat neuros*” OR AB “combat neuros*” OR TI “traumatic stress” OR AB “traumatic stress” OR TI”shell shock” OR AB “shell shock”
Here is what a record of these two search strategies on PsycINFO would look like
Use the Advanced Search option in PsycINFO
- Copy and paste the first set of terms into the first search box
- Now copy and paste the second set of terms into the second search box
Normally Boolean logic would require that you enclose each set of terms in parentheses to ensure that the logic worked properly, but pasting the searches into separate boxes in PsycINFO fulfills the same purpose, and ensures that each term in each set is matched with each term in the other set when you combine the contents of the two boxes using AND.
| 
