Using PubMed to Find Evidence-Based Medicine Articles

MEDLINE is an excellent source for a comprehensive search of the biomedical literature. This database of 11 million journal citations and abstracts covers nearly 4,500 journals published in the United States and 70 other countries. The PubMed system provides free public access to MEDLINE (along with selected life sciences journals not in MEDLINE).

Unlike filtered resources such as the Cochrane Database of Systematic Reviews, all of the articles included in MEDLINE are not evidence-based. Special search strategies and techniques are needed to filter through the millions of MEDLINE references to find the articles that can be considered the best evidence, studies that are both systematically researched and clinically relevant.

The most effective way to search for evidence-based articles of interest to clinicians is to use the Clinical Queries option on the PubMed sidebar under PubMed Services .

Three searching choices are available, depending on your needs. You can search the PubMed database according to clinical study categories, for systematic reviews in particular, or for articles specific to topics in medical genetics. PubMed's online tutorial offers an interactive demonstration of the searching process for both clinical queries and systematic reviews.

Searching by Clinical Study Categories

• Therapy - clinical studies on treatment (search default)
• Diagnosis - clinical studies on diagnostic determinations and procedures
• Etiology - clinical studies on the origin and causes of a disease
• Prognosis - clinical studies on the probable outcomes of a disease

• Sensitivity - also known as "recall;" retrieves larger number of articles but probably includes some less relevant hits
• Specificity - also known as "precision;" will retrieve fewer, more relevant articles (search default)

Select the category and scope appropriate for your search using the radio buttons. Enter your search terms and click Go. PubMed will process your inquiry based on a table of relevant pre-set filtering terms selected by RB Haynes et al

Finding Systematic Reviews

According to the National Library of Medicine (NLM), producers of MEDLINE, "this strategy is intended to retrieve citations identified as systematic reviews, meta-analyses, reviews of clinical trials, evidence-based medicine, consensus development conferences, guidelines, and citations to articles from journals specializing in review studies of value to clinicians."

What is the difference between a review and a systematic review? A fact sheet from NLM clarifies the differences.

Enter the terms you are interested in searching in the search box, then click Go.

Medical Genetics Searches

A new feature of the Clinical Queries page is the ability to search for articles that deal with medical genetics. Note that there are a number of different options available, and that the default is to search for all of them. You will want to select the areas of interest to you by checking one or more of the boxes. Enter your search terms in the box, and click Go.

For additional information on using PubMed for evidence-based searching, see:

• Evidence-Based Medicine Resource Center
  Fact sheet with suggestions for limiting your searches (from the New York Academy of Medicine's library)
• Finding the Evidence on PubMed
  Detailed instructions on other EBM searching options (from Yale University's medical library)

For additional information on using other resources for evidence-based searching, see:

• "Using Electronic Health Information Resources in Evidence-Based Practice"
  One in a series of JAMA Users Guides to Evidence-Based Medicine
• "Navigating the Maze: Obtaining Evidence-Based Medical Information"
  Descriptions of EBM databases and web resources (from the University of Virginia's Health Sciences Library)

For access to additional evidence-based medicine databases at UNC-Chapel Hill:

• Clinical Quick Reference page.