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How to Search for Clinical Studies

Learn how to search for clinical studies from the ClinicalTrials.gov home page, and how to narrow down your search results to find the clinical studies that are most important to you.

To learn how to search for clinical studies, find studies that are looking for participants, or find the total number of studies on ClinicalTrials.gov, see this series of short videos on the ClinicalTrials.gov Demonstration Videos(https://www.nlm.nih.gov/oet/ed/ct/demo_videos.html) page.

Quick guide to searching for clinical studies

From the home page

Start by typing in words or phrases in at least one of the basic (default) search filters.

  • Condition or disease (for example, breast cancer or high blood pressure)
  • Other terms (for example, a treatment, NCT number, or investigator name)
  • Intervention/Treatment (for example, radiation therapy or low fat diet)
  • Location (search by address, city, state, or country)

Select the Study Status

  • Already set to search for “All studies” or
  • Select “Recruiting or not yet recruiting studies” to search only for studies that are looking for participants

Click the Search button on the bottom right side of the screen.

To add More Filters to your search:

To add more search filters on the home page, open the More Filters menu by clicking anywhere on the gray bar or by using the + on the bar.

  • Select specific filters from the menu of options
  • To remove a filter, uncheck the box next to the filter or if it’s a text box, click the X on the far-right side.

Click the Search button to start your search.

You can select as many of the search filters as you want, and the Search tool will look for studies that include all the items you have selected.

The Search button will stay at the bottom of your screen as you scroll up and down the page.

Helpful features

  Click on this to see the glossary definition for the term.

  Click on this to clear a text filter.

Questions to ask before you search

To help you find specific studies , think about the information that is most important to you.

  • Do you want to find clinical studies focused on a certain disease?
    • Use the Condition or disease filter. Type in the name of the disease or condition and select from the drop-down list.
  • Are you looking for studies located close to home or other location?
    • Use the Location filter and search by “Current location” or enter an address and select from the drop-down list. You may need to allow the website to use your location.
    • Use the radius bar to select the number of miles you are willing to travel.
  • Do you want to know about studies that use a specific treatment?
    • Use the Intervention/Treatment filter and type in the name of the treatment and select from the drop-down list.
  • Are you interested in participating in a clinical study?
    • Change the Study Status filter to Recruiting and not yet recruiting studies. Those are the studies looking for participants.

Detailed guide to searching for clinical studies

Doing a basic search

Use the basic (default) search filters that are already on the home page.

  • Condition or disease: Use this field to search for studies related to a condition, disease, disorder, syndrome, illness, or injury.
  • Other terms: Use this field to narrow down a search using other filters, such as the:
    • Specific treatment
    • Name of the study investigator
    • ClinicalTrials.gov Identifier (NCT Number)
  • Intervention/Treatment: Use this field to search for studies that use a specific drug, medical device, procedure, or lifestyle change.
  • Location: Use this field to find studies in or near a certain place.
    • Search by your current location by selecting Current Location in the location filter and make sure your browser is set to allow access to your current location.
    • Start by typing in an address. After you type a few letters, a list of suggestions will appear.
    • Select from the drop-down list.
    • Use the radius bar to pick the number of miles you are willing to travel.
    • To find all the studies in a certain state, type in the name of the state.
    • To find all the studies in a certain country, type in the name of the country.
    • If you are not interested in finding a study near a specific location, leave the Location filter blank.
  • Study Status will be set to search “All studies” but can be set to search only for studies that are looking for participants (Recruiting and not yet recruiting studies).

Narrowing your search

To narrow your search, you can add More Filters from the home page or from the search results page. Adding more filters will give you fewer, more specific results.

  • From the home page, you can include more filters by choosing the + sign or by clicking anywhere on the More Filters bar at the bottom of the search page. For example, you can add search filters to find studies for a certain age group, or studies that are finished and have results posted.
    • Select the filters you want to apply. For example, under Eligibility Criteria, you can select studies that are looking for adults from 18-64 years old.
    • When you have chosen all the filters you want to use, click the Search button to start your search.
  • From the search results page, use the Focus Your Search menu on the left side of the screen. Open the More Filters by clicking on the bar or by clicking the + and scroll down the list.
    • Select the filters you want to apply to your search. The number in parentheses next to the filter name tells you how many clinical studies include that feature.
    • When you have chosen the filters you want to use, click the Apply Filters button at the bottom of the menu.
  • Note that the Apply Filters button will be greyed out until you select the filters you want to apply to your search.

Special instructions for using certain search filters

Other terms

This field is a tool to help narrow down your search for clinical studies. For example, you can use this field to search for studies that use a certain drug or studies with a specific word in the title or study description. Other example terms you can use in this field include:

  • The NCT number
  • The acronym for a study
  • A biomarker or gene name
  • An intervention
  • An outcome measure

Facility Name filter

Use this filter to search for studies in a certain hospital or institution. Facility Name is found under the category, More Ways to Search.

  • From the home page, open the More Filters menu by clicking on the bar or using the +.
    • Type the name of a facility, such as a hospital or institution.
    • After you type a few letters, a list of suggestions will appear. Choose a facility from the list or keep typing to use a facility not on the list.
  • From the search results page, start at the Focus Your Search menu on the left.
    • Scroll down the list of filters to More Ways to Search to find the Facility Name filter.
    • Type the name of a facility, such as a hospital or institution.
    • After you type a few letters, a list of suggestions will appear. Choose a facility from the list or keep typing to use a facility not on the list.

Eligibility Criteria filter

Use this filter to find studies that are looking for participants with specific characteristics to participate in the study. Eligibility Criteria are found under the More Filters menu on either the home page or under the Focus Your Search menu on the search results page.

  • Use this filter to find studies that Accept Healthy Volunteers or that enroll participants who are a certain Sex or Age
  • Under Eligibility Criteria:
    • Leave the Sex as All, or change it to Female or Male to narrow your search. Sex refers to biological sex.
    • To add an age, use one of the two options listed below:
    • Under Selected Ranges, choose Child, Adult, or Older adult
    • Use the Manually Enter Range filter:
      • In the From and To filters, type a number and choose an option from the drop-down list (for example, years, months, or weeks). Use a decimal for ages in between years (for example, enter 1.5 for 1½).
      • Note: The From age must be less than the To age
  • Click the Search button on the home page, or select Apply Filters at the bottom of the Focus Your Search menu on the search results page

Date Range filters

Use these filters to finds studies using key study dates and dates related to the study record, such as studies that started, were updated, had results posted, or were completed on a certain date. Date Range filters are found under the More Filters menu on either the home page or under the Focus Your Search menu on the search results page.

  • To enter a date range:
    • Choose dates using the calendar icons or
    • Enter dates using the mm/dd/yyyy or m/d/yyyy (month, day, year) format.
  • Click the Search button on the bottom of the menu to start your search, or select Apply Filters on the search results page.

More ways to search

Finds studies by using:

  • Title/acronym: Use to this field to search for studies with certain words in the title, or search for the abbreviated name (sometimes called an acronym) of a study. For example, the RECOVER study.
  • Outcome measure: Use this field to search for the effect (outcome) of a specific treatment or intervention. For example, decreased mortality, reduced pain, or increased heart rate.
  • Sponsor/collaborator: Use this field to search for studies by the organization or person who has control over the study (called the sponsor) or by an organization that provides support for the study (called a collaborator).
  • Sponsor (Lead): Use this field to search for studies based on the sponsor of the study
  • Study IDs: Use this field to search for a study using the identification number or code assigned by a grant, another study registry, or by the ClinicalTrials.gov Identifier (NCT Number).
  • Facility Name: Use this field to search for studies located in a specific facility, such as a hospital or institution.
  • FDAAA 801 Violations: Use this field to search for studies with a FDAAA 801 violation.

General tips

Using phrases, NOT and AND to help search

  • If your search term (the word or phrase you use for your search) is a phrase of two words or more, put quotation marks around the words so the Search looks for an exact match:
    • For example, to search for breast cancer, type “breast cancer” to find studies that contain the whole search term (the exact phrase).
    • Without quotation marks, the Search will find studies that contain each word separately. For example, a search for breast cancer will find studies that contain only the word cancer and studies that contain only the word breast.
  • To exclude a word or phrase from your search, type the word NOT (in all capital letters) before the term you don’t want to search for.
    • For example, a search for immunodeficiency NOT AIDS will find studies of immunodeficiencies that are not related to AIDS.
  • To search for studies that contain two separate concepts, type the word AND (in all capital letters).
    • For example, a search for heart disease AND yoga will search for studies that include both heart disease and yoga.

Other general tips:

  • The first letter of a search term (the word or phrase you use for your search) can be a capital or lowercase letter. If you put a capital letter in the middle of your search term, it will affect your search results.
  • If you don't get the search results you expect, check the spelling and capitalization and try again.
  • For many filters, a list of suggestions will appear when you type the first few letters of your search term. Choose from the list or keep typing until your selection appears.
  • You don’t have to add and fill in every field on the home page –fill in the fields for the information most important to you. The Search tool will find results using one or many search terms.
  • If you are searching for clinical studies about a specific disease or condition, the Search tool will give you a list of other names for that disease or condition that were included in your search. You can find these by clicking on Synonyms of conditions of disease at the top of your search results page.
Last updated on June 10, 2024