The World Health Organization has launched a search portal for clinical trials, describing it as “an enormous step towards greater access, transparency and accountability of health research globally."

Accessible at, the portal provides an entry point, with a global search function, to clinical trial registers that are part of a new WHO Network of Collaborating Clinical Trial Registers.

To date, this includes just three registers that meet the organisation’s requirements for Primary Register status and contribute data directly to the WHO’s Clinical Trial Search Portal: the Australian Clinical Trial Registry;; and the International Standard Randomised Controlled Trial Number Register.

Also contributing data to the portal, but only via one of the primary registers, are ArQule, Inc (in partnership with; Dutch Trial Register (with ISRCTN); Eli Lilly (; Mitsubishi Pharma Corporation (; and Physician Data Query (

A number of other registers, such as the Chinese Clinical Trial Register, the Clinical Trials Registry – India, the German Somatic Gene Transfer Clinical Trial Database, the South African National Clinical Trial Register and the Latin American Clinical Trials Register, are being assessed by the WHO’s Registry Platform Secretariat to determine whether they satisfy the requirements for a Contributing Register.

The 'only way' to ensure complete trials info

These include agreement to register studies prospectively (i.e., before the first participant is recruited), which the WHO sees as the “only way to ensure the availability of complete and accurate information about clinical trials”. Registering trials is “a scientific, ethical and moral responsibility”, says the organisation, which last year launched the International Clinical Trials Registry Platform, a global network calling for the registration of all studies on humans.

Contributing Registers also have mechanisms in place to ensure the optimal quality of the data collected, the WHO notes. Moreover, the registers must publicly disclose their ownership, governance structure and for-profit status.

Any register that logs clinical trials prospectively can be either a contributing or non-contributing register in the new WHO network, which is designed as a forum for participants to exchange information and work together towards establishing best practice for clinical trial registration.

The WHO acknowledges that clinical trial registers “have now become widely accepted as an essential part of an overall strategy for improving health outcomes”. The challenge, though, is knowing how to navigate through the ever-increasing number of registers and to identify which ones provide accurate and reliable information, it adds.

A significant proportion of research is never published and “even if it is published, it is possible that only part of the story is told in the publication”, the WHO comments. Relying on information sourced only from published trial research is “therefore unreliable and leads to inadequately informed treatment decisions."