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Downloading Content for Analysis

This page is recommended for advanced users. It explains how to download study record data in Extensible Markup Language (XML), a machine-readable format, and in other data formats.

The structure of study records in XML is defined by this XML schema.

Use of ClinicalTrials.gov data is subject to these Terms and Conditions.

Contents

Download Study Information From a Search Results List

The Download option on the Search Results page is an advanced feature that allows you to download information about some or all of the study records shown in the search results:

Download option on the Search Results page

Click on the Download link (shown above), which is located in the upper-right corner of the List tab on the Search Results page. A pop-up box containing download options will appear:

Download search results form

Number of Studies: Choose the number of records you want to download using the dropdown list. Your options are:

  • The top 10, 100, or 1,000 studies retrieved by your search. These options will be available only for searches that find as many or more than the specified number of studies. For example, if your search finds fewer than 1,000 studies, "Top 10 Studies" and "Top 100 Studies" can be selected, but "Top 1000 Studies" will not appear in the dropdown list.
  • The studies displayed on the current Search Results page, usually listed as "20 Shown Studies" in the dropdown list
  • All studies retrieved by your search. For example, if your search finds 151 studies, "151 Found Studies" will appear in the dropdown list.

Download Content:

Download Multiple Study Records in XML

Choose one of the following options to download a separate XML file for each study:

  • Download All Study Fields as XML. Choose this option to download only the protocol information (shown on the Full Text View tab on the study record page).
  • Download All Study and Results Fields as XML. Some completed studies have results information posted on ClinicalTrials.gov (shown on the Study Results tab on the study record page). Choose this option to download both protocol and results information, when available. Please note that many studies do not contain results information because this feature was added in September 2008 and because results information is required only for some completed studies. See About the Results Database for more information.

Download a List of Records

Choose this option to download a single list of records. You can select the study information that will be included for each record:

  • Download Selected Fields.
    • Select fields. Use the dropdown list to choose the study fields that you want to download from your search results list. You can choose to download either the fields shown onscreen or the available fields. The default study fields shown onscreen are Condition and Intervention. To change which fields are shown in your search results, close the window you are in, click on the Show Display Options link (located in the upper-left corner of the search results List tab), and then add or remove fields by marking or unmarking the checkboxes.
    • Select file format. Use the dropdown list to select one of the following formats for your saved file:
      • Plain text: Unformatted text that can be read in a simple editor, such as Notepad
      • Tab-separated values: Each study record is saved as a separate line in the file, with tabs as delimiters, or spacers, between each field. This format is useful for importing study information into spreadsheets and databases.
      • Comma-separated values: Each study record is saved as a separate line in the file, with commas as delimiters, or spacers, between each field. This format is useful for importing study information into spreadsheets and databases.
      • XML: XML is a machine-readable format that will be most useful to advanced users.

The study records or list file will be downloaded as a zip file, or compressed package. Click on the Download Zip File button to save this file to your computer. (Sample zip file readers with free trial periods: WinZip and PKZip)

Note: It may take several minutes to download a large number of studies.

Use URL Parameters to Display and Save XML Data

Display a Single Record in XML

To display an individual study protocol record in your browser in XML, add the URL parameter "displayxml=true" to the end of a "show study" URL:

Some completed studies have results information posted on ClinicalTrials.gov (see How to Find Results of Studies). To include both protocol and results information, choose a study with posted results and use the URL parameter "resultsxml=true":

The resultsxml output is a superset of the protocol and study results XML. Do not include both the displayxml and resultsxml parameters in the URL.

Download Multiple Records in XML

To immediately begin downloading protocol records in XML, add the URL parameter "studyxml=true" to the end of a "search request" URL:

Some completed studies have results information posted on ClinicalTrials.gov (see How to Find Results of Studies). To include both protocol and results information, use the URL parameter "resultsxml=true":

The resultsxml output is a superset of the protocol and study results XML. Do not include both the studyxml and resultsxml parameters in the URL.

Note: It may take several minutes to download a large number of studies.

Download Database Extracts From the Clinical Trials Transformation Initiative (CTTI) Database for Aggregate Analysis of ClinicalTrials.gov (AACT)

CTTI, a public-private partnership, has restructured and reformatted ClinicalTrials.gov data into a relational database under its Improving the Public Interface for Use of Aggregate Data in ClinicalTrials.gov project.

The CTTI AACT Database page provides database extracts as zip files in three formats:

  • Oracle dmp
  • Pipe-delimited text output
  • SAS CPORT transport

Supporting documents, such as a comprehensive data dictionary, a high-level data dictionary, and a document outlining points to consider, are also available on the AACT Database page.

This page last reviewed in December 2015