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Evidence-Based Research: MEDLINE Search Help

Introduction

The MEDLINE with Full Text database is an unfiltered database that contains over 5,000 full-text journals related to the biomedical and health fields. While the database itself is unfiltered, you can still use it to find filtered, evidence-based practice resources, including systematic reviews. Cochrane Database of Systematic Reviews is included in Medline. You can also use it to find unfiltered resources, including randomized controlled trials, case studies, and other primary research studies.

On this page you will learn how to limit your results in MEDLINE to:

  • systematic reviews
  • randomized controlled trials
  • cohort studies
  • case studies
  • other document types

Set up your search

Here is an example of how to put together a complex search in MEDLINE:

  1. On the Library homepage, find the Research by Subject button.
     

    Research by Subject

  2. Click on Research by Subject and choose: Nursing.
  3. Click on the Nursing Databases section and choose MEDLINE with Full Text.
     

    Note: If you have not already logged in to the Library databases, you will be prompted to log in with your myWalden Portal user name and password.

  4. Once you are in the database, use the search boxes to enter your keywords. For example, in the first search box, enter:
     

    Neonatal OR NICU

     

    Note: You can use OR to link together your synonyms, or related words, in a search box, allowing the database to search more broadly.

  5. In the second search box enter:
     

    Handwashing OR "Hand Washing" OR "Hand Rubs" OR "Hand Disinfection"

     

    Note: Putting quotation marks around phrases tells the database to search for these words as a phrase and not as individual words.

  6. In the third search box enter:
     

    "Infection Control" OR "Cross Infection"

     

 

Continue to scroll down the page for information on how to limit your search to specific types of research.

Systematic reviews

You can find a number of systematic reviews in MEDLINE. Once you have set up your search, here is how you can limit your results to only systematic reviews:

  1. Scroll down the page below the search boxes until you find the Subject Subset box.
  2. In the Subject Subset box select Systematic Reviews by finding it in the list and clicking on it (it will then be highlighted).
     

     
  3. Click on the Search button to run your search.

Randomized controlled trials

Randomized controlled trials are the studies commonly used to support systematic reviews and are a high level of evidence.

Once you have set up your search, here is how you can limit your results to only randomized controlled trials:

  1. Scroll down the page below the search boxes until you see the Publication Type box.
  2. In the Publication Type box select Randomized Controlled Trial by finding it in the list and clicking on it (it will then be highlighted).
     

     
  3. Then click on the Search button to run your search.

Cohort studies

Cohort studies are a type of longitudinal study, or observational study, that analyze risk factors by following groups that share a common characteristic or experience over time. Since these studies have a long-term component, they promote a better quality of evidence than a shorter study. There are also fewer of them, and they are harder to find.

Here is an example of a search for a cohort study in MEDLINE:

  1. Set up your search. For example, in the first search box you could enter:
     

    Neonatal

  2. In the second search box, enter any additional keywords. For example, you could enter:
     

    "Infection Control"

     

    Note: Putting quotation marks around phrases tells the database to search for these words as a phrase and not as individual words.

  3. In the third search box enter:
     

    "Cohort Studies"

     


     

  4. Then click on the Search button to run your search.

Case studies

A case study, or case report, is a research method involving a detailed investigation of a single individual or a single organized group. Case studies may be prospective (in which criteria are established and cases fitting the criteria are included as they become available) or retrospective (in which criteria are established and cases are selected from historical records for inclusion in the study).

Once you have set up your search, here is how you can limit your results to only case studies:

  1. Scroll down the page below the search boxes until you find the Publication Type box.
  2. In the Publication Type box select Case Reports by finding it in the list and clicking on it (it will then be highlighted).
     

     
  3. Click on the Search button to run your search.

Other filters in MEDLINE

MEDLINE with Full Text offers a number of additional filters or limiters that can help you find specific types of studies.

Scroll down the page below the search boxes to locate these filters or limiters. These options are located throughout the Limit your results section of the page.

Clinical Queries

This filter can be used find articles that are clinically-sound. The nine options are: 

  • Therapy
  • Diagnosis
  • Prognosis
  • Reviews
  • Clinical Prediction
  • Guides
  • Qualitative
  • Causation (Etiology)
  • Costs
  • Economics

To get the most results, select all three sub-divisions: High Sensitivity, High Specificity, and Best Balance.

Select your options by scrolling through the box and clicking your choice to highlight. Hold down the Ctrl key to select multiple options.

 

Publication Types

This limiter box allows you to select specific article types.. We've already shown how to use this limiter for randomized controlled trials and case reports; other useful publication types for evidence-based practice include Clinical Trial, Comparative Study, Meta Analysis, Practice Guideline, and Validation Studies.

Select an option by finding it in the list and clicking on it (it will then be highlighted).

 

Medline EBM Reviews limiter

This limiter limits your search to only the following evidence-based medicine resources:

  • The Cochrane Database of Systematic Reviews
  • ACP Journal Club
  • Clinical Evidence
  • Evidence-based Mental Health
  • Evidence-based Nursing
  • Evidence report/Technology assessment

Click in the check box below EBM Reviews to select this option.

 

Note: With the EBM Reviews limiter you will need to evaluate your results to determine what type of evidence each article contains.