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Study registries

Study registries are databases that store data such as study titles, short descriptions, inclusion and exclusion criteria, study status and endpoint for ongoing and completed studies. The registration of studies is increasingly required by third-party funding bodies and journal associations. is a comprehensive registry of ongoing and completed clinical trials worldwide, maintained by the U.S. National Institutes of Health.

  • Coverage: The register contains over 400,000 entries from more than 200 countries (as of 11/2022), with a focus on the English-speaking world. Some of the results and research data of the respective studies are also linked under the tab Study Results.
  • Registration: Studies can be registered via the Protocol Registration and Results System (PRS). Prior personal or institutional registration is required.
  • Search options/data export: The portal offers detailed search functions (advanced search, thematic and geographical search) and data export as XML, CSV or TXT file. See also Find Studies > ... and the Search Details tab page after the search.

The register is integrated in the "ICTRP Search Portal".

ICTRP Search Portal

The International Clinical Trials Registry Platform (ICTRP) Search Portal is an international meta-registry of clinical trials of the WHO, which integrates most of the study registries in one search portal.

  • Coverage: A comprehensive search for completed and ongoing studies from all countries is possible. Updating takes place weekly or monthly.
  • Registration: The ICTRP Search Portal does not provide for the registration of clinical trials, which is done through study registries such as DRKS or
  • Search Options/Data Export: The search options are limited, the search works best on the home page with few words without brackets, wildcards and quotation marks, see Search Tips. Data export is currently only possible as CSV (for e.g. Excel) or XML file.

DRKS - German Register of Clinical Studies

The German Clinical Trials Register is the national primary register for clinical studies in Germany and is compiled by the University Hospital of Freiburg. It fulfils the requirements of the ICMJE, for which the registration of a clinical study is a prerequisite for the publication of articles on it.

  • Coverage: Since 2008, the DRKS has recorded information on ongoing and completed clinical studies in Germany.
  • Registration: The registration of studies is explicitly desired and is required by certain third-party funding agencies (BMBF, DFG). For this purpose, prior personal registration is required.
  • Search options/data export: The portal offers detailed research functions (especially according to study design and recruitment). An export is possible as PDF, HTML, CSV or XML file.

The register is integrated in the "ICTRP Search Portal".

EU Clinical Trials Register

The EU Clinical Trials Register is a register of drug trials conducted within the EU, which has been in existence since 2011. It is compiled by the European Medicines Agency (EMA) and is fed from the non-public database EudraCT.

  • Coverage: The registry records approximately 37,000 entries (as of 03/2020) on ongoing and completed drug trials since 2004 within the EU and the European Economic Area.
  • Registration: The registration of studies is not possible. The data on the studies come from the national health authorities of the individual countries (for Germany these are the Federal Institute for Drugs and Medical Devices and the Paul-Ehrlich-Institute).
  • Search options/data export: The portal offers good research functions (especially according to study phase and recruitment status). Data export is possible as TXT file.

The register is integrated in the "ICTRP Search Portal".


  • Clinical and epidemiological studies are mainly divided into interventional (or experimental) and observational study types.
  • Published studies are usually documented in article databases such as PubMed.
  • Clincal decision support databases such as DynaMed and systematic reviews evaluate published studies and guidelines with the highest possible evidence.

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