Deficiencies in the transfer and availability of clinical trials evidence: a review of existing systems and standards

Table 2 ClinicalTrials.gov and the 14 WHO primary registries, with the number of registered trials per 19 March 2012 (‘studies’), whether the register is indexed by the WHO search portal (‘indexed’) and whether the registry also enables results publication (‘results’)

Register	Studies	Indexed	Results
ClinicalTrials.gov (United States)	122,758	yes	yes (5,436)
European Union Clinical Trials Register	17,102	no	no
ISRCTN register (international)	10,465	yes	no
Japan Primary Registries Network	8,329	yes	no
Australian New Zealand Clinical Trials Registry	6,369	yes	no
The Netherlands National Trial Register	3,187	yes	no
Clinical Trials Registry - India	2,499	yes	no
Iranian Registry of Clinical Trials	2,449	yes	no
Chinese Clinical Trial Register	2,004	yes	no
German Clinical Trials Register	831	yes	no
Cuban Public Registry of Clinical Trials	392	yes	no
South Korea Clinical Research Information Service	379	yes	no
Brazilian Clinical Trials Registry	131	no	no
Pan African Clinical Trial Registry	97	yes	no
Sri Lanka Clinical Trials Registry	71	yes	no

ISSN: 1472-6947