How to Use Search
- How to Use Search
- Search for a Specific Phrase
- Search Term Highlighting
- Searches Using the Operators OR, NOT, and AND
How to Use Search
- Enter a word or phrase into one or more of the search fields:
- Use Condition/Disease for terms such as asthma or breast cancer. This tells the search function to find all studies with the disease, disorder, syndrome, illness, or injury that was entered. You can choose one of the suggested terms or type in your own.
- Use Other Terms for additional words or terms you want to search by. You can use this to search for a specific NCT number, drug name, an investigator's name, or other term.
- Use Country to limit your search to a specific country, such as the United States. A pull-down list of countries is available. If you choose United States from the pull-down menu, a search field for State will appear. If you want to search for studies taking place in a specific state, choose one from the pull-down menu. If you want to search the entire United States, leave the State search box blank.
Click on one of the following buttons to conduct the search:
- Use Find a Study to Participate In to find only those studies that are currently recruiting (or accepting) participants.
- Use Search All Studies to search all studies that contain your search terms.
- Use Advanced Search for more options to narrow your search so that you find studies most likely to fit your needs. (For more details on Advanced Search, see How to Use Advanced Search.)
- A list of search results will be displayed. The total number of studies found is shown, along with your search terms.
- The first column of the search results list, Row, indicates the order in which the studies are listed. Studies that most closely match your search terms are listed first. The Status column shows which studies are recruiting new volunteers and which studies are not recruiting new volunteers. (For more details on search results, see How to Use Search Results.)
- You do not need to use all the search fields. Fill in only the fields that are needed for your search.
- To find studies of a specific disease, use the Condition/Disease field to return more precise search results.
Search for a Specific Phrase
Medical terms are often several words long. How you enter those words into the search field will affect the list of studies the system finds.
To find only studies that use the words together as a phrase, put the entire phrase in quotation marks, as shown below:
"percutaneous coronary intervention"
Using quotation marks means that the search results will include only studies that use that phrase or a synonym of that phrase.
If you search for a multi-word term without using quotation marks, you will find all the same studies and possibly more studies. The studies with all the words appearing together as a phrase will be listed higher in the search results than studies where the words are separated and spread throughout the document.
For example, the results for a search using the phrase heart attack (without quotation marks around the phrase) will include a study about:
Use of a Pacemaker Following a Heart Attack
higher in the search results list than a study about:
Heart Defects and Transient Ischemic Attacks
The results of a search for "heart attack" (with the phrase in quotation marks) would not include the second study because the words do not appear together as a phrase.
Search Term Highlighting
The words you type in the search fields will be highlighted in the text of the study record. Search words and synonyms for search words will be highlighted. For example, if your search words are heart attack, the words "heart" and "attack" as well as synonyms for heart attack, such as myocardial infarction, will be highlighted.
Searches Using the Operators OR, NOT, and AND
Words such as OR, NOT, and AND (in uppercase letters), are known as search operators. You can use these words to tell the ClinicalTrials.gov search function to broaden or narrow your search. Here are some ways you can use search operators:
- Use OR to find study records that contain any of the words connected by OR.
Example: aspirin OR ibuprofen
This search finds study records containing either the word "aspirin" or the word "ibuprofen." Using OR broadens your search.
- Use NOT to find study records that do not contain the word following NOT.
Example: immunodeficiency NOT AIDS
This search finds study records containing the word "immunodeficiency" but excludes records containing the word "AIDS" from the search results. Using NOT narrows your search.
- AND is not necessary because the search function will automatically find study records that contain
all the words specified in the search. However, you may use AND to separate distinct concepts.
- How to Use Search Results: Learn how to change the search results display.
- How to Read a Study Record: Learn about the information found in a study record.
- How to Find Results of Studies: Learn about results information available for some studies.