WHO statement for public disclosure of clinical trial results

Simon Collins, HIV i-Base

On 14 April 2015, the World Health Organization (WHO) updated its 2005 statement on the public disclosure of results from all interventional clinical trial. [1, 2]

A paper outlining the rationale for the new position was also published online in the free-access journal PLoS Medicine. [3]

The new statement now defines time lines for reporting, including older but still unpublished trials, and outlines ways to improve the links between clinical trial registries and the published results. This includes reporting studies that produced negative or inconclusive results.

Similar demands are stated in the latest version of the Declaration of Helsinki. [4, 5, 6]

A paper published last year on large studies (>500 participants) registered on and completed by 2009, reported that 23% still had not published results after a median of 60 months since the studies ended. [7]

Although shorter timeframes are strongly encouraged, maximum reporting time frames include that:

  1. The main findings of clinical trials are to be submitted for publication in a peer reviewed journal within 12 months of study completion. They are to be published through an open access mechanism unless there is a specific reason why open access cannot be used, or otherwise made available publicly at most within 24 months of study completion.
  2. Key outcomes are to be made publicly available within 12 months of study completion by posting to the results section of the primary clinical trial registry.
  3. Unreported clinical trials conducted in the past are to be disclosed in a publicly available, free to access, searchable clinical trial registry. In addition, it is desirable that unreported clinical trials are published in a peer-reviewed journal.
  4. Publications should always include the trial ID number.


  1. World Health Organization (WHO). WHO statement on public disclosure of clinical trial results (14 April 2015).
  2. Link to the statement.
  3. Moorthy VS et al. Rationale for WHO’s new position calling for prompt reporting and public disclosure of interventional clinical trial results. PLoS Med 12(4): e1001819. doi:10.1371/journal.pmed.1001819.
  4. World Medical Association. World Medical Association Declaration of Helsinki: Ethical Principles for Medical Research Involving Human Subjects. JAMA. 2013; 310(20):2191–2194. doi: 10.1001/jama. 2013.281053.
  5. Hudson KL, Collins FS. Sharing and reporting the results of clinical trials. JAMA. 2015 Jan 27; 313 (4):355–6. doi: 10.1001/jama.2014.10716.
  6. Chalmers I. Underreporting research is scientific misconduct. JAMA. 1990 Mar 9; 263(10):1405–8.
  7. Manzoli L, Flacco ME, D’Addario M, Capasso L, De Vito C, Marzuillo C, et al. Non-publication and delayed publication of randomized trials on vaccines: survey. BMJ. 2014 May 16; 348:g3058. doi: 10. 1136/bmj.g3058.

Links to other websites are current at date of posting but not maintained.