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Dietetics Internship

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PubMed for Mobile Devices

See LHL's PubMed for Mobile Devices page to read.

Levels of Evidence & PubMed Filters

An evidence pyramid is a visual representation of the strength of evidence. When possible, clinical decisions are based on studies at the top of the pyramid.

The level of evidence is based on the research design used to conduct the study. The most scientific, rigorous designs are randomized controlled trials, systematic reviews, and meta-analysis. These designs reduce opportunities for bias and confounders.

  • Bias refers to the systematic error that occurs in the design, conduct or interpretation of a study which may cause a deviation for the underlying truth.
  • Confounders occur when a factor disturbs the true relationship of the study variable because it is also relating to the outcome variable being measured.

Use the "Article Types" filters on the left sidebar in PubMed to limit your search to Meta-Analysis, Systematic Reviews or Randomized Control Trials.  "Practice Guidelines" is also available. If you choose more than one, the limiters will be searched with OR.

Clipboard

Use PubMed's Clipboard feature to save results temporarily.

  • Run your search
  • Check the boxes next to the article you wish to move to the Clipboard
  • In top right corner of results page, click Send to > Clipboard

The Clipboard:

  • can collect up to 500 citations
  • will be lost after 8 hours of inactivity
  • can be emailed to yourself and/or another student by going to Send to  > E-mail

PubMed Search Tips

  • Use Advanced Search page to see your search history and rerun searches
  • Use MeSH headings and subheadings to focus search
  • Apply limits (age groups, publication type, etc.) to focus your search
  • View “related citations” to expand your search
  • Consider “Clinical Queries"
  • Link to full text articles with the Full Text@UAB Libraries button
  • Remember PubMed does not include everything
  • Ask a librarian if you get stuck!

Finding Brand New Articles in PubMed on Your Topic

Don't forget that while searching by MeSH Terms is great for doing focused, relevant searches it may prevent you from seeing any brand new articles that have been published on your topic. There is a lag between the time citations/abstracts appear in PubMed and when they are tagged with MeSH Terms. So if you only search the MeSH Terms field, you will miss those articles that have not yet been assigned MeSH Terms.

Solution: In addition to searching using MeSH Terms, be sure to also run keyword searches for your topic. You can "NOT out" the articles you would have found from a MeSH search so that you don't have to sort through a bunch of duplicates. Here's an example:

Search #1 - Search using MeSH Terms: Child Development Disorders, Pervasive[MeSH Terms] AND Anxiety Disorders[MeSH Terms] AND Cognitive Therapy[MeSH Terms]

Search #2 - Search using keywords: autism AND anxiety AND (cognitive therapy OR cognitive behavior therapy) NOT medline[sb]

The last piece of this keyword search statement will weed out all articles that have been tagged with MeSH Terms and which you would already have searched using the first search.

Remember, keyword searches search "All Fields" for all the terms in your search statement, so this second search statement is searching the citation information, abstract, etc. for the keywords you've entered. You may have to include different keywords connected with "OR" if there are synonyms for your concepts, as I've done here with cognitive therapy and cognitive behavior therapy.

My NCBI Tutorials

Sign up for a My NCBI account to:

  • Save searches and individual citations
  • Set up automatic search alerts that are sent by email
  • Select display formats and features like highlighting search terms in result lists
  • Set up search filters for search limits you frequently use

Click the box below to view a tutorial on saving searches and setting up auto search alerts:

Click below to learn how to set up search filters:

Click below for a tutorial on saving individual results to a collection:

What is PubMed?

Topics covered: biomedical literature from MEDLINE, life science journals, and online books

Size: more than 24 million citations

Types of documents indexed: Mostly articles, but some online books

Date range: 1950s to present

Access: You can access PubMed from this guide or the Lister Hill Library homepage. On the homepage, click the PubMed icon in the middle of the page. (Note: Once you graduate, you can access PubMed at www.pubmed.gov )

To learn more about PubMed see our PubMed via LHL Guide and on the National Library of Medicine website.

Selecting MeSH Terms for Your PubMed Search

The following 9-minute tutorial demonstrates how to find appropriate Medical Subject Headings (MeSH Terms) for a PubMed search. Specifically, the tutorial walks you through:

  1. Doing a keyword search and looking at Search Details to see what MeSH Terms PubMed translated the search to
  2. Pulling up a very relevant article and looking at what MeSH Terms were assigned to that article
  3. Using the MeSH Database to look up keywords and seeing what MeSH Terms PubMed suggests

In your own searches, you will likely find yourself using a combination of these three approaches.

Note: Click the to Full Screen button on the bottom right  to expand the tutorial to full screen.

Search PubMed Using Medical Subject Headings (MeSH)

This 9-minute tutorial demonstrates how to perform a subject search in PubMed using MeSH Terms.

Note: Click the to Full Screen button on the bottom right  to expand the tutorial to full screen.

Tips for Finding the "Evidence" in PubMed

PubMed includes some filters and specialized search tools that can be used in your search for evidence-based literature (see below for more information).

Filters

One way to narrow results to evidence-based works in PubMed is to filter search results to only specific types of articles such as randomized control trials, meta-analyses, reviews, practice guidelines, etc. To do this:

1) Go to PubMed

2) Enter your search terms and click the Search button

3) On the left side of your search results list under Article Types, click the filters you want. Some specific types you may want to consider are Meta-AnalysisPractice GuidelineRandomized Controlled Trial, and/or Review articles. If you don't see these options listed, click the "More..." link at the bottom of the filter category.

Clinical Queries

Another method for finding evidence-based sources in PubMed is to use the specialized search tools located on the Clinical Queries page. To use these tools:

  1. Go to PubMed
  2. Click on the Clinical Queries link
  3. Enter your search terms and then click Search. You may need to revise/broaden your search statement when using this Clinical Queries search since the search is narrower than a normal PubMed search would be. In this example, instead of searching using MeSH Terms (which is usually a more focused search), I've just used keywords.
  4. The results page is divided into three columns, so you can, for example, quickly look at just clinical studies (and select the specific clinical category or degree of specificity you want) or systematic reviews on your topic.

 

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