There is a FDA regulation mandating publishing of basic results after 1 year of trial competition.

http://clinicaltrials.gov/ct2/about-site/results

There are currently about 7936 studies with "Results": http://clinicaltrials.gov/ct2/results?term=&recr=&rs...

Also, several major journals require authors to adhere to data reporting guidelines of CONSORT: http://www.consort-statement.org/home/