Literature Searching in Ovid Medline – Using
subject headings to search a question. In this video, you will learn the difference
between keyword and controlled vocabulary searching as well as scope notes, auto-explode,
tree structures, subheadings and combining sets using Boolean operators. We can start by typing in music therapy and
then clicking on search. Make sure the “Map Term to Subject Heading” is checked. This will take us to the subject heading page.
There are a number of things that need to be covered here. To begin with, notice that
the term ‘music therapy’ occurs twice, once in blue print and once in black print.
If you choose the term in black print you will search ‘music therapy’ as a keyword,
which will search the title and the abstract of articles for the occurrence of the words
‘music therapy’. The term in blue is called a medical subject
heading or MeSH heading for short. MeSH headings are ‘controlled vocabulary terms’, they
search for the concept expressed by the term no matter what words are used to designate the concept. This is why you want to make sure that the
map term to subject heading box is checked on the search page so that Medline will map
you to the MeSH heading that corresponds to the term that you typed in. The scope note defines the MeSH term, this together with the see related and used for can help determine whether this is the MeSH heading you need. Notice that when you check the select box
to the left of a MeSH term, the box under Auto Explode is checked as well. An explodable
term is a general term that has more specific terms indexed beneath it. Medline automatically
explodes terms unless you tell it not to by unchecking the box under Auto Explode. To
get a better idea of explodable terms let’s look at where music therapy falls in the tree
structure. To access the tree structure just click on the blue MeSH term. MeSH headings are organized in species/genus trees, where the broader terms are at the
top of the tree and more specific terms are further down the tree. Let’s scroll down
and find where music therapy is in the tree structure Music therapy is indexed under the broader heading of Sensory Art Therapies along with dance therapy, play therapy, and a few others. If you exploded Sensory art therapies, Medline would also search the other terms that are indexed below and to the right of Sensory Art therapies. Finally, if you choose to restrict
your term to focus you will only get those articles where music therapy is the primary
focus of the article. I would be careful about restricting your term to focus right off the
bat because you run the risk of excluding potentially useful articles. You will want
to consider restricting your search to focus only if your completed search has too many
citations. If you click on continue, Medline will take you to the subheadings page. A subheading, or qualifier is a way to restrict
the focus of your search by qualifying it in a specific way. You don’t have to choose
any of the subheadings if none seem applicable and even if some do seem applicable I tend to
avoid using subheadings at the start of my search for the same reason that I avoid restricting
my search to focus. In both cases you run the risk of excluding useful articles. We have now completed searching for the term
musical therapy. Let’s search our next term ‘anxiety’. Unlike ‘music therapy’, which only mapped
us onto one MeSH term ‘anxiety’ has mapped us onto several MeSH terms. Let’s take a
look at the tree structure to see how these different kinds of anxiety are related to
each other. Notice that there are more specific types
of anxiety indexed under the general term anxiety. Even though it is unlikely that dental
anxiety or castration anxiety will be relevant to our specific search let’s go ahead and
explode anxiety anyway just in case. We can either check the box under Explode on the
tree structure page… or we could return to our subject heading
page, where ‘anxiety’ is automatically exploded, and click on ‘Continue’. Notice that we have a completely different
list of subheading for anxiety than we had for music therapy. This makes sense when you
consider that ‘anxiety’ is an emotional state and ‘music therapy’ is a kind of
treatment. In the case of a disease, for example, you will have subheadings such as therapy
and rehabilitation while in the case of a If you will recall the topic of our search
was the use of music therapy to relieve anxiety in pediatric cancer patients. We have already
searched ‘music therapy’ and ‘anxiety’, let’s try oncology for our next search term.
This list of MeSH terms just doesn’t seem right. Let’s look at the scope note to see
if that can help us find out what went wrong. According to the scope note medical oncology
is a subspecialty of internal medicine concerned with the study of neoplasms. Since we are
interested children with cancer and not the doctors who treat them, let’s try another
search statement. We can click on Search to take us back to the search page.
Let’s search ‘cancer’ instead. This maps us onto neoplasms instead. The scope
note on medical oncology claimed that neoplasms was related to oncology but just to make sure
we’re on the right track, let’s look at the scope note for neoplasms.
This looks more like it, notice that cancer is listed as one of the terms used for neoplasms.
Let’s return to the previous page and search ‘neoplasms’
As before let’s skip choosing any subheadings. We still have the pediatric patient part of
our search to perform but we can do that using the limit commands. But at this point we want to combine our three search terms together using the Boolean Operator AND. When you combine three sets together using the Boolean operator AND you only get those articles that contain the intersection of all three terms. You should now know what the difference is between a keyword and a controlled vocabulary term. what a scope note is, what auto-explode is, what tree-structures are, what subheadings are and how to combine a search using Boolean Operators.