Remember, literature searching is a combination of an art and a science. It requires practice, intuition, and some trial and error. While there is a basic structure, a set of guidelines and many tools for assisting one with basic searches, there are a variety of nuances and advanced techniques that may be required for more specialized searches. (from "Conducting a winning literature search," Erika D. Ecker and Andrea C. Skelly)

Digital Health Evidence provides its results by executing searches against the PubMed database, so the rules for constructing a good Digital Health Evidence search are the same as those for constructing a good PubMed search. For guidance on how to approach your search and develop your query see Conducting a winning literature search.

One specific tip for refining results that you may notice behind many of the "Quick Searches" is the use "boolean logic":

Add terms or combine search terms with connector words: AND, OR, or NOT using upper case letters (called Boolean logic)

  • AND between terms returns only records that contain all of the search terms
  • OR between terms returns all records that contain any of the search terms
  • NOT between search terms returns only records that contain the first term and not the second

Here are the queries behind the "Quick searches" for FPRH and Systematic Reviews demonstrating the use of boolean logic (also of note are the use of parentheses to group conditions):

family planning OR (reproductive OR sexual) health
(systematic review OR meta-analysis) NOT protocol

More advanced searching can be conducted using Medical Subject Headings or "MeSH" terms:

It is important to understand that PubMed uses a controlled vocabulary to index journal articles called MeSH and uses “automatic term mapping” to find MeSH terms when you search. MeSH terms are organized in a hierarchy called a tree, with more specific (narrower) terms arranged beneath broader terms. By default, PubMed includes in the search all narrower terms; this is called “exploding” the MeSH term. Inclusion of MeSH terms enhances and optimizes the search strategy.

For example, the query behind the "Quick search" for Governance uses the MeSH terms "public policy," "health planning" and "legislation as topic":

governance OR public policy OR health planning OR government regulation OR legislation as topic