Full description and examples
The standard search finds trial records containing particular terms (words or phrases) in any of the following fields:
- Title (both public and scientific)
- Primary sponsor
- Health Condition(s) or Problem(s) studied
- Countries of recruitment
- Main ID
- Secondary ID(s)
The standard search is sensitive, finding as many relevant records as possible. For a more targeted (specific) search you may want to use the Advanced Search
Main ID search
The standard search finds partial matches of a trial's Main ID. For example, searching for 17647 finds records with Main IDs such as ISRCTN01764719, NCT00517647 etc.
The default order of search results is by descending date of registration. You can change the sorting to a different field by clicking on its heading in the results table:
Clicking on the same heading again reverses the order of sorting.
The standard search looks for trial records containing synonyms of search words or phrases using the UMLS metathesaurus
The standard search strips out the following characters from your search terms: ( ) [ ] " $
To search for a phrase simply enter the words together in the search box. You do not need to enclose them in quotation marks. So, to search for the phrase diabetic retinopathy simply enter
The standard search treats an asterisk (*) at the end of a string of letters as a wild card and looks for any word beginning with the letters already entered. So, a search for:
finds records with any of the words bacterial, bacteraemia, bacteriological.
Note: Truncation disables synonym searching! This means it may reduce search sensitivity. For example, a search for liver cance* may result in less hits than a search for liver cancer (which also searches for synonyms).
Truncation in phrases
It is best to avoid truncation in phrases. The search engine does not return any hits if truncation is applied to words at the beginning of a phrase. For example:
does not return any hits, but
does return hits, as does
Truncation of the last word in a phrase is treated as truncation of all words in the phrase, so a search for
finds records containing the phrase liver cancer.
This also works for phrases composed of more than two words, so a search for
prim bil cirrhos*
finds records containing the phrase primary biliary cirrhosis.
Combining words or phrases
Use Boolean operators to combine search terms (either words or phrases):