A review of the effects of the legislation governing clinical trials in the European Union has backed up some researchers' complaints about the regulations.

The 2001 European Clinical Trials Directive, which came into force from 2004, was intended to harmonize the rules governing clinical trials. But it has faced criticism from researchers who think it is overly complex and bureaucratic (see Nature doi:10.1038/news.2009.163; 2009).

Last week, the final report from the European Commission-funded project assessing the directive concluded that the measures increase workloads on trial sponsors and ethics committees, and delay the start of trials. The number of commercially-sponsored clinical trials in Europe increased by about 30% between 2003 and 2007, the report adds, whereas the number of non-commercially sponsored clinical trials remained constant.