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Evidence-Based Medicine: EBM & PubMed / Medline

Welcome to Evidence-Based Medicine (EBM) guide that is intended to provide basic information about EBM with special emphasis on searching and evaluating studies retrieved using Medline, PubMed, Cochrane and other Internet resources.

EBM & Medline

Because not all articles indexed in Medline contain evidence that could be directly applied to patient care, you have to apply special filters that would retrieve only EBM documents.

To find the best research evidence available in Ovid Medline, search Medline as explained in the Medline tutorial, then click on "Limits", then "Additional Limits" and under the section "Clinical Queries" select the appropriate EBM filter.

Suppose you want to see if there is evidence about effectiveness of needle biopsy in diagnosing prostatic cancer.
Search Medline OVID as discussed in Medline tutorial; click "Limits" then "Additional Limits". One of the limiting options displayed is "Clinical Queries" that allows filtering of evidence-based citations.

Clinical Queries has options according to the following categories: therapy, diagnosis, prognosis, reviews, clinical prediction guides, qualitative studies, etiology, costs, and economics. For each one of these you have three choices: sensitivity (produces largest number of records, from which some are not relevant), specificity (produces highest level of relevancy and the least number of citations with the possibility of missing one), and optimized (results are in between the sensitivity and specificity options).

Limit the last result from search history ("prostatic neoplasms" and "needle biopsy") with the diagnosis (optimized) filter to limit retrieval to EBM literature. If not satisfied, select to limit by "diagnosis (specificity)" or "diagnosis (sensitivity)".

When searching for EBM it is advisable not to Focus the MeSH terms, and to OR MeSH with its keyword.

EBM & PubMed

From SML homepage click on PubMed@SML. There you find a link "Clinical Queries" that has built-in search filters to retrieve EBM citations that could be applied to provide best patient care.

This Clinical Queries page is divided into 3 sections that could be searched for a particular question:

  • Clinical Study Categories
  • Systematic Reviews
  • Medical Genetics

For example to see if there is evidence for treatment of otitis media with antibiotics in children, type in the box otitis media antibiotics and click "Search".

In the first category and by default, "therapy" is selected as "Category" and "Broad" is selected under "Scope".

For diagnosis, etiology, prognosis, or prediction question, select the category option accordingly.

You will see directly the number of records retrieved with the first five displayed and a See all link at the end of displayed results.  If you retrieve too many results, change "Scope" option to "Narrow" to get fewer hits that are more relevant and focused.

Similarly the middle section "Systematic Reviews" displays the first five results and at the end there is a See all link.  The last section is for "Medical Genetics".

Note: remember that the hits you retrieve from PubMed or Medline need critical appraisal or evaluation.