Along with the efforts of individual journal editors to include negative trials, there have been recent public and private initiatives to increase public access to clinical trial results.
The U.S. NIH policy is that the results of its funded research should be available to the public.
We have already discovered that ClinicalTrials.gov provides updated information for locating U.S. government- and privately-supported clinical trials and results of certain completed trials. Observational studies addressing health issues in large groups of people or populations in natural settings are also included in the ClinicalTrials.gov database.
The site was developed by the U.S. National Institutes of Health (NIH), through its National Library of Medicine (NLM), in collaboration with the Food and Drug Administration (FDA), as a result of the FDA Modernization Act (1997). The types of trials required to be registered at the site expanded with the Food and Drug Administration Amendments Act of 2007. The "basic results" of trials that study drugs, biologics, or devices approved, licensed, or cleared by the FDA are now required to be posted in a timely manner. (read more about the registration requirements page and the clinical trials results page)
Many medical journals now have policies of only publishing a manuscript from a completed clinical trial if the trial has been registered at ClinicalTrials.gov.
Along with satisfying legislative requirements, pharmaceutical manufacturers are providing access to results from sponsored studies through various mechanisms. (e.g.GSK, Pfizer, Merck) as the Pharmaceutical Research and Manufacturers of America and the European Federation of Pharmaceutical Industries and Associations adopted joint Principles for Responsible Clinical Trial Data Sharing (2013).