European Union Trials Databases
Access to European trial information is currently via two resources:
The European Clinical Trials Information System (CTIS) is a developing databse with information on clinical trials in the EU and EEA and was launched on 31 Jan 2022. The Clinical Trials Information System includes 147 records (13 April 2023).
The European Union Clinical Trials Register (EU-CTR) provides access to trial protocols and summary trial results information for interventional clinical trials conducted in the European Union (EU) and the European Economic Area (EEA) and trials conducted outside the EU / EEA that are linked to European paediatric-medicine development. The database coverage is for trials initiated before 31 Jan 2022. The status of studies in Great Britain is no longer updated from 1 Jan 2021.
Further details on the two registers are available.
The EU-CTR can also be searched via the ICTRP.
It also provides access to trials from the EudraCT database.
EU-CTR has records for over 42,000 trials with a EudraCT protocol (18 May 2022).
Search details for both resources are provided below.
In July 2018 the BMJ reported that of 7274 trials where results were due, 49.5% reported results. In 2019 the European Commission reported that of 27,093 completed trials in EudraCT, 68.2% had results posted. In July 2021 the BMJ reported that nearly 6000 clinical trial results are missing from the registry.
The EU-CTR registry record includes information on whether trial results are available and searches can be restricted to records with results by using the Advanced Search option. Trial results, where available, are included in the record.
Publications relating to the registers are listed at the bottom of this page.
Search options for CTIS
Default operator The Basic Search interface offers "contains all of these terms" (AND) or "search one of the terms" (OR)
Boolean operators The Basic search interface offers a proxy OR search by searching in the "Contain any of these terms" option.
A proxy AND search is offered by the "contains all of these terms" option.
There is also a "Does not contain any of these terms" (NOT) option
Phrase searching Not available
Nesting Not available
Truncation Not available
Field tags The advanced criteria option provides the keyword search plus lookup lists and checkbox filters
Hyphens Unclear
Help pages Yes
Saved searches No
Export tagged Records can be downloaded one by one.
Each record is downloaded as a zipped file with all the data and files that have been selected.
Search options for EU-CTR
Default operator AND **
Boolean operators AND, OR, NOT
Use +to specify a required word e.g. +pain
Phrase searching "breast cancer"
Nesting Yes
Truncation The register offers synonym searching. There is no truncation.
Field tags Filters and fielded searching are available through the Advanced Search option
Hyphens Hyphens are treated as spaces
Help pages Yes
Example (cancer OR neoplasms) AND pain
Saved searches There is an RSS feed option to receive updates.
Export tagged Yes, plain text download for trials with a EudraCT protocol (limit of 20 records per download).
** The default operator WAS ‘OR’ as per the ‘How to search the EU Clinical Trials Register – booklet’, but is now 'AND'
Selected References
DeVito NJ, Goldacre B. Trends and variation in data quality and availability on the European Union Clinical Trials Register: A cross-sectional study. Clinical trials (London, England) 2022; 19(2):172–83.
European Commission. Letter to stakeholders regarding the requirements to provide results for authorised clinical trials in EUDRACT. European Commission; 2019.
Steinbrook R. The European Medicines Agency and the Brave New World of Access to Clinical Trials Data. Arch Intern Med. 2012:1-2. doi:10.1001/jamainternmed.2013.3842
Doshi P, Jefferson T. The first 2 years of the European Medicines Agency’s policy on access to documents: Secret no Longer. Arch Intern Med. 2012:1-2. doi:10.1001/jamainternmed.2013.3838
Information about clinical trials in the EU.
Updated 13 April 2023