DNAP 761

In addition to keywords, you can also use controlled vocabulary, or subject headings, to find research. Subject Headings are expecially helpful when your keyword search is full of articles that are not relevant to your search, or when there are a ton of different ways to describe the concept (i.e., too many synonyms).

 Problem: Too Many Synonyms

In Health Sciences research, there are often many ways to talk about a topic. There is language that is used with the public, as well as medical terminology (i.e., allergies vs hypersensitivity). Knowing which term to use can be overwhelming! Subject headings take the drama out of that process by allowing you to use a single term that will retrieve all articles that are mapped with that subject heading, regardless of what language they use in the actual article.

A great example is nose bleeds. There are a ton of ways this concept can be expressed:

• Nosebleed 
• Nose bleed 
• Bloody nose 
• Nasal bleeding 
• Epistaxis 
• Nasal hemorrhage

You could construct a search that tries to find every synonym, such as (Nosebleed OR Nose bleed OR Bloody nose OR Nasal bleeding OR Epistaxis OR Nasal hemorrhage). Or... you can just use a subject heading.

In Pubmed, the Medical Subject Heading for nose bleed is epistaxis.

  Click here to view in PubMed's MeSH Database.

 Problem: Irrelevant Results

Keywords search for the word anywhere in the record. There might be an article that says, "For the purposes of this study, we chose to not look at adults with Parkinson's Disease." If you search for the keyword "Parkinson's Disease," this article would appear because they mentioned your keyword, even though the article specifically states it is not about that topic!

Here is an example. Say you are looking for articles about labor (specifically, about childbirth) and you see articles that look like this:

The word labor is in the title of these articles, but neither of them are about childbirth.

You also might get a result like these:

The first is authored by Marina Labor, while the second was published in the Journal of Labor Economics. Neither are relevant to your search, but include the keyword "labor."

Keyword searches are designed for a broad search, while subject headings provide a more focused search. For example, using the subject heading "Labor, Obstetric"[mh] in PubMed would bring back more focused search results.

keyword search = 1,885,973

MeSH search = 48,607