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USF Health Libraries

Public Health Library Guide


Search Tips

Databases generally want keywords (synonyms & controlled vocabulary) rather than an entire question. 

For example: rather than typing "Which is better for acute coronary syndrome: drug-eluting stents or bare-metal stents?" just pick out the key ideas:

acute coronary syndrome
drug-eluting stent
bare-metal stent

Then look for synonyms, variant spellings and controlled vocabulary as described below.

Synonyms - searching for synonyms will broaden your search, for example: cancer OR neoplasms OR carcinomas

Variant Spellings - American and British spellings are oftentimes different, so searching pediatric OR paediatric gives broader coverage.

Databases and Controlled Vocabulary (Subject Headings)

Abbreviations -  If the abbreviation is well-known you may want to search both the abbreviation and the full name (i.e., AIDS OR Acquired Immunodeficiency Syndrome); other abbreviations may bring up too many false results

Quoted Phrases - The use of quotation marks around a phrase such as "end of life" or "stress reduction" assures the words are found together and cuts down on unrelated citations. Don't use quoted phrases that are identified as controlled vocabulary terms.

Truncation - use of a symbol to search the stem of a word with any ending.  For example, test* would include tests, testing, tested.  Most databases use the asterisk (*)  as the truncation symbol. Don't use truncation on terms that are identified as controlled vocabulary as it turns off the mapping that is happening in the background.

Field Searching - this allows you to search for terms or phrases only in the title and abstract, or just as a text word.  How you do this varies in each database.  In PubMed, to search title and abstract you add [tiab] after your term.  

Parentheses - The parentheses are important in searching, just like in math! When constructing you search, keep your "OR" phrases as distinct groups. One way to do this is to create a parentheses pair for each set of synonyms you will be searching joined by AND. So you would start with something like this: () AND () AND () for three concepts. Parentheses ensure that the database doesn't apply the wrong Boolean operator to the term. Now go back and put in your OR phrases: (saw palmetto OR serenoa repens) AND (benign prostatic hyperplasia OR prostate hypertrophy OR BPH) AND ("disease management" OR "illness management").

An easier way to do this may be to construct your search by searching each concept separately and then joining them together using your search history or Advanced Search. There may be times when a controlled vocabulary term bridges two or more concepts that will need to be OR'd into the search. The important thing is to keep the concepts separate or you'll end up with many irrelevant search results!

Adjacency  - some databases allow the use of symbols to show nearness or adjacency between words such as N3 or W3.  Check the help files to determine if the database you are searching allows this. Ovid Medline, Embase and CINAHL all allow some form of adjacency searching.

For best results, use a combination of all the search tips!

Boolean Operators

The most common Boolean operators are ANDOR, and NOT. These can be used to refine or expand your search so that you retrieve just the right articles. We will be going over this in more depth in class but here's the basics:

OR - always expands your search (a good mnemonic is remember that OR = MORE). Use this for synonyms.

AND - always contracts your search by making it more picky (All articles you return should have both concept 1 & concept 2.

NOT - excludes articles containing this concept. So if I search for (Diabetes Mellitus Therapies NOT insulin), I would be telling the database not to include any articles with the word insulin in the title or abstract. Be careful using the NOT Boolean operator!  It's very easy to eliminate articles you would want to see!

Search Matrix

The search matrix is a method of organizing your search concepts.  In a search for how healthcare disparities influences infant mortality, add healthcare disparities in Concept 1 column and OR all the synonyms.  Add Infant Mortality to the Concept 2 column and OR all those synonyms.  Now AND Concept 1 and Concept 2 to find the overlay.


Search Frameworks

A well-defined research question helps identify the concepts to search to answer your question.  Search frameworks help you create a research question by suggesting elements you to consider. Not all questions are suited for a single framework. Several of the more common frameworks are found below.


  • Population/Patient/Problem - What is the population or characteristics?
  • Intervention - What is the intervention, prognostic factor, treatment, etc.?
  • Comparison - What is the comparator, if any?
  • Outcome - What are the expected outcomes, improvements, measures, etc?

       May also include one or more of the following:

  • Time - Is there a specific time-frame involved?
  • Type of Question - Diagnosis, Therapy, Etiology/Harm/Prevention, Prognosis
  • Type of Study - Prospective, Retrospective, Cohort, Case-Control, Randomized Controlled Trial, etc.


  • Population/Patient/Problem - What is the population or characteristics?
  • Intervention - What is the intervention, prognostic factor, treatment, etc.
  • Setting (if appropriate) - Hospital, Outpatient, School, Rural
  • Comparison or intervention (if appropriate) - What are you comparing the intervention with?
  • Outcome  - What is the outcome you want to measure or achieve


  • Setting - What is the setting/context? Where?
  • Population/Perspective - Who are the users, potential users, stakeholders of the particular service? For whom?
  • Intervention - What is being done? 
  • Comparison - What else has been tried?
  • Evaluation - What measurement will be used to determine the success?  What is the result?


  • Expectation - Why is the information needed?
  • Client Group - Who needs, or will use, the information?
  • Location - Where is the service taking place?
  • Impact - What is being evaluated? How will success be measured?
  • Professionals - Who provides the service?
  • Service - What is the service being evaluated?

SPIDER (Qualitative)

  • Sample – Who is engaging in the research?
  • Phenomenon of Interest – What or how are we trying to understand (experiences, behaviors, decisions) of participants?
  • Design -  Theoretical framework (questionnaire, survey, interview, etc.)
  • Evaluation - What measurement will be used to evaluate the PI?
  • Research Type - Qualitative or mixed methods

Term Brainstorming

  • When creating comprehensive searches such as for systematic reviews where several different databases are being searched, you need a method of keeping track of the controlled vocabulary and synonyms used in each database. This link is a working document that can be used to record terms from different databases and includes places to look that you wouldn't necessarily think of like entry terms or previous indexing terms (PubMed), Emtree synonyms or candidate terms (Embase), etc..

Peer-Reviewed or Referred Articles


Refereed or peer-reviewed articles are reviewed by an editorial board, a committee of academic peers or referees prior to the article being accepted for publication by a journal.  The document is reviewed by the reviewers for content, methodology, etc.

Peer-reviewed materials are very significant to the research in most academic fields because they represent reliable scholarship which advances the knowledge in the discipline.

To determine if a journal is peer reviewed, look up the journal title in Ulrich'sWeb Global Serials Directory and look for the icon of a referee's t-shirt.  If the journal is peer reviewed, all the articles in the journal are peer reviewed except for editorials, books reviews and any other clearly opinion pieces.