REMS (Research Experience for Medical Students)

Databases


Research Question


The first step in EBM is to ask a well-built, patient-oriented question. Formatting your research question as a PICO question is a great way to accomplish this.

P - Patients or Population:
Who are the relevant patients?

I - Intervention(s) or Exposure(s):
For example, diagnostic tests, foods, drugs, surgical procedures, time, or risk factors. What are the management strategies we are interested in comparing or the potentially harmful exposures about which we are concerned?

C - Comparator:
For issues of therapy, prevention, or harm, there will always be both an experimental intervention or putative harmful exposure and a control, alternative, or comparison intervention or state to which it is compared.

O - Outcome:
What are the patient-relevant consequences of the exposures in which we are interested? We may also be interested in the consequences to society, including cost or resource use. It may also be important to specify the period of interest.

 

Framing Clinical Questions: PICO. In: Guyatt G, Rennie D, Meade MO, Cook DJ. eds. Users' Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice, 3rd ed. McGraw-Hill; Accessed April 30, 2021.

 

The following worksheets provide additional approaches to writing PICO questions.

Search Tips


Broad Search

Consider how you can specify the main concepts that are part of your topic. For example, if you are interested HIV transmission prevention programs for prisoners, you can think about the “building blocks” of your question as:

  • HIV
  • prevention
  • prison

A search like this will find results about HIV prevention programs for prisoners. Doing a broad search at first and then adding more terms or using the limiters in a database to narrow your results down often makes for much less frustration.

Complex Search

Keep in mind that there may be more than one term that means the same thing, or something very similar. 

For example:

  • Prisons or jails or inmates or prisoners or incarceration
  • teen or teenager or adolescent or youth
  • HIV or AIDS or STD or sexually transmitted diseases

You will also find keywords to try in your readings and in your notes from class.   Making a list of synonyms for your search terms is often a good strategy for searching, to be prepared in case you don’t get as many results as you had hoped.

 

Controlled Vocabulary: Descriptors, Subject Headings, Or MeSH

Many databases also use specific keywords or terms called descriptors that are assigned to articles on that topic.  Once you know the descriptors for your topic it can make it easier to pull all articles on the same topic together at the same time.  In many cases the descriptor will be the medical term – just be aware that terminology changes.   You will find descriptors (often called Subject Headings) in database search results by looking at the individual records for articles.  Many databases for the health sciences (PubMed, CINAHL) use the Medical Subject Headings (MeSH terms), so becoming familiar with the MeSH terms associated with your topic will be useful. 

Here are a few examples of keywords and their MeSH terms (some terms are more obvious than others!)

Everyday language MeSH
Cardiovascular disease, CVD Cardiovascular diseases
Breast cancer Breast Neoplasms
Health disparities Healthcare disparities OR Health status disparities
AIDS Acquired Immunodeficiency Syndrome (“HIV Infections” would be the broader term)
Elderly Aged

 

Combining Terms for a more Complex Search

Once you identify the terms (keywords or descriptors) applicable to your question or topic, put them together with Boolean operators such as AND (for more precision in your search), OR (to enlarge the pool of results when more than one situation is concerned), or NOT (to exclude possible elements that might jeopardize quality for quantity in your results.  (Be careful using NOT though, as you may exclude useful results!)

Tip: Each database has its own thesaurus to organize articles on certain topics. Take a look at the database’s thesaurus to see if it uses a different term if your search does not yield enough results on your topic. 

Tip: Put quotes around search terms that are phrases (contain more than one word).  For example, placing quotes around “Mediterranean diet” will locate articles for you in the databases containing the phrase “Mediterranean diet” and should weed out all the articles where those words appear separately from each other (for example, an article about trying to be on a diet while on a cruise ship on the Mediterranean Sea!). THIS IS NOT TRUE FOR PUBMED.