Doctors cannot choose the best treatments for their patients despite the existence of hundreds of thousands of randomised trials. The main reason is that research results are being reported selectively. Comparisons of published drug trials with unpublished data available at drug regulatory agencies have shown that the benefits of drugs have been much over-rated1 2 3 and the harms under-rated.4 Comparisons of trial protocols with published papers have also shown widespread selective reporting of favourable results.5 6

Selective reporting can have disastrous consequences. Rofecoxib (Vioxx) has probably caused about 100 000 unnecessary heart attacks in the United States alone,7 and class 1 antiarrhythmic drugs probably caused the premature death of about 50 000 Americans each year in the 1980s.8 An early trial found nine deaths among patients taking the antiarrhythmic drug and only one among those taking placebo, but it was never published because the company abandoned the drug for commercial reasons.9

Allowing researchers access to unpublished trial reports submitted to drug regulatory agencies is important for public health. Such reports are very detailed and provide more reliable data than published papers,1 2 3 4 but it has been virtually impossible to get access to them. We eventually succeeded in getting access to reports held by the European Medicines Agency (EMA) after three years of trying. Our case has set an important precedent, and we summarise here the process and the arguments.