Information Mastery: Navigating the Maze
The Pyramid
Types of EBM Information Sources Available, with Examples
(ranked according to the "Usefulness of Medical Information
Equation")
The Secrets of the Pyramids
Search Protocol:
- The pyramid above is a graphical representation of how to
search efficiently for the best evidence. The examples of EBM
information sources in this pyramid are placed from top to bottom
according to the "Usefulness of Medical Information" equation
illustrated below:
| Usefulness = |
Relevance x Validity |
| ? |
Work |
- This model suggests that you start your search at the top of
the pyramid with systematic reviews from the Cochrane Database of
Systematic Reviews. Cochrane is small in the amount of
information it currently contains, making it easier to search,
but large in the validity and relevance of the information it
contains for answering therapeutic questions.
- Depending on the success of your search in Cochrane, you
would work your way down the pyramid of resources in order of
decreasing relevance/validity and increasing work, until you find
an answer.
- Journal articles form the base of the pyramid because they
represent large amounts of "unrefined" information, and the
burden of determining the validity and relevance is up to the
user. The work part of the "Usefulness Equation" is also very
high for journal articles as it may require a lengthy MEDLINE
database search to locate them.
Searching and Alerting Tools:
- With the ever-growing number of pre-validated information
sources available, clinicians now need two tools to help them
identify information that is highly relevant and valid: an
Alerting Tool and Searching
Tool.
- A good Alerting Tool would notify the
clinician whenever new relevant information becomes available. An
example of such a tool would be Daily
InfoPOEMs - a companion product to
InfoRetriever (a searching tool) from
the company InfoPOEMs: The Clinical Awareness
System.
- A good Searching Tool would search multiple
databases or sources of information simultaneously and present
the results in an easy-to-use format based on relevance and
validity.
- The pyramids below illustrate several such Searching
Tools. Not all search tools are equal, and when using
one it helps to evaluate it by asking the following questions:
- Does it search information sources that have a high
usefulness score (higher on the pyramid)?
- Does it search multiple information sources
simultaneously?
- Does it rank its search results according to usefulness (top
of pyramid sources listed first)?
- Does it answer the highest percentage of questions in the
least amount of time?
Search Tool: Ovid's Evidence-Based Medicine Reviews
(EBMR)
(sources ranked according to the "Usefulness of Medical
Information Equation")
Search Tool: InfoRetriever
(sources ranked according to the "Usefulness of Medical
Information Equation")
Search Tool: TRIP Database
(sources ranked according to the "Usefulness of Medical
Information Equation")
Search Tool: SUMSearch
(sources ranked according to the "Usefulness of Medical
Information Equation")
