Table 2. An overview of each registry, listing its acronym, full name, country where it is based, countries from where registration is accepted, type of registration allowed, type of study hosted, and language used.
| Registry acronym | Registry full name | Country where registry is based | Countries from where registration is accepted | Type of registration allowed | Type of study | Additional language1 |
|---|---|---|---|---|---|---|
| ANZCTR | Australian New Zealand Clinical Trials Registry | Australia | All countries. However, trials in Australia and New Zealand are prioritized | Prospective, Retrospective2 | Interventional, Observational | – |
| ChiCTR | Chinese Clinical Trial Register | China | All countries | Prospective, Retrospective | Interventional, Observational, Others | Chinese |
| CRIS | Clinical Research Information Service | Republic of Korea | Republic of Korea | Prospective, Retrospective | Interventional, Observational | Korean |
| CTG3 | ClinicalTrials.gov | USA | All countries | Prospective Retrospective | Interventional, Observational, Expanded Access | – |
| CTRI | Clinical Trials Registry—India | India | Other countries in the region which do not have a Primary Registry of their own4 | Prospective | Interventional, Observational, PMS5, BA/BE5 | – |
| DRKS | German Clinical Trials Register | Germany | All countries | Prospective, Retrospective | Interventional, Observational, Epidemiological, Others | German |
| EU-CTR | EU Clinical Trials Register (EU-CTR) | The Netherlands | All interventional trials that have at least one centre in the EU and EEA. Certain trials conducted entirely outside these regions. | Prospective. Retrospective if permitted by National Competent Authority of the Member State | Interventional | Older trials may have content in the host country’s language |
| IRCT | Iranian Registry of Clinical Trials | Iran | All countries | Prospective | Interventional | Persian |
| ISRCTN | International Standard Registered Clinical/soCial sTudy Number | UK | All countries | Prospective, Retrospective2 | Interventional, Observational | – |
| JPRN | Japan Primary Registries Network6 | Japan | All countries | Prospective, Retrospective | Interventional, Observational | Japanese |
| LBCTR | Lebanon Clinical Trials Registry | Lebanon | Lebanon | Prospective | Interventional, Observational | Brief summary of the study is also available in Arabic |
| NTR | Netherlands Trial Register | The Netherlands | Trials conducted in Netherlands or involving Dutch researchers. | Prospective, Ongoing studies | Interventional, Observational | Some information may be available in Dutch |
| PACTR | Pan African Clinical Trials Registry | South Africa | All countries in Africa | Prospective, Retrospective | Interventional | – |
| ReBEC | Brazilian Registry of Clinical Trials | Brazil | Brazil4 | Prospective Retrospective | Interventional, Observational | Portugese and Spanish, for some records, and in a limited way |
| REPEC | Peruvian Clinical Trial Registry | Peru | Peru | Prospective | Interventional | Spanish |
| RPCEC | Cuban Public Registry of Clinical Trials | Cuba | Cuba7 | Prospective, Retrospective | Interventional Observational | Spanish |
| SLCTR | Sri Lanka Clinical Trials Registry | Sri Lanka | All countries | Prospective | Interventional | – |
| TCTR | Thai Clinical Trials Registry | Thailand | Thailand | Prospective | Interventional, Observational | – |
1. All registries are required to be in English. However, some provide content in additional language(s).
2. Retrospective registration is allowed but prospective registration is preferred and encouraged.
3. Except CTG, all the acronyms listed are the official acronyms.
4. For two registries (CTRI, REBEC) the information on the ICTRP portal and on their own websites is discrepant. Upon inspection, the latter sources appear to be correct, and we have described the registries accordingly.
5. PMS: post-marketing surveillance; BA/BE: Bioavailability/Bioequivalence.
6. Common forum for trials from three Japanese registries, that is (UMIN Clinical Trials Registry (UMIN-CTR), Japan Pharmaceutical Information Center Clinical Trials Information (JAPIC-CTI), and Japan Medical Association—Center for Clinical Trials (JMACCT)).
7. Trials are accepted from Cuban sponsors, conducting trials in Cuba or abroad, with Cuban or foreign products.
Notably, some registries (ChiCTR, EU-CTR, ISRCTN, PACTR, REPEC) were built on earlier versions.