Clinical Trial FAQs

As part of our ongoing efforts, Embase will ingest around 65,000 clinical trial records from ClinicalTrials.gov to complete the backfill from the May release.

These additional clinical trial records will be added between 13th October to 16th October 2025. We will be adding 20,000 trials per day and the process will complete by 16th October.

During this period, you may notice an increase in the number of search results as the new content becomes available.

When this data load takes place, the API queries will return clinical trials by default, in the same way they are included in the embase.com search results.
To exclude clinical trials from your API results, add any one of the following conditions to your search query:

• NOT 'clinical trial'/it (this excludes based on publication type)
• NOT 'clinical trial':dtype (this excludes based on database collection)
• NOT 'clinicaltrials.gov'/jt (this excludes based on the journal title "clinicaltrials.gov")

If you do not apply filters to exclude this additional content, you will notice an increase in the number of search results you receive.

Following the data load, the update folders will begin to include this additional content, and the subsequent monthly bulk file will also contain the full Clinical trial backfill.

Users can determine if a Clinical Trial record in the XML output is new or updated by checking the state attribute within the <ait:status> element.

For new clinical trial, the state attribute will include new

<ait:status stage="S300" state="new" type="core"/>

For updated clinical trial, the state attribute will include update

<ait:status stage="S300" state="update" type="core"/>