A third of clinical trials haven’t published results

Research published today has found that nearly a third of clinical trials have not published results five years after they ended. The study looked at 585 large trials registered on the clinical trials register ClinicalTrials.gov that had ended before January 2009. One hundred and seventy-one of these trials (29%) had not published results by November 2012. Non-publication of results is more common among industry funded trials (32%) than non-industry funded (18%).

The authors estimate that 250,000 people who volunteered to take part in a clinical trial on the understanding that findings generated would benefit society and help other patients in the future had their trust betrayed. Richard Stephens, a cancer patient who has taken part in five clinical trials said “Patients become participants to add to knowledge and to eliminate uncertainties. Hiding results, no matter what the reason, isn’t in that spirit at all.”

Today’s paper is in line with findings from other recent research:

  • A 2010 study found that a third of drug trials conducted between 2000 and 2006 had published results. Thirty-two percent of industry funded and 56% of non-industry funded trials had published results.
  • A 2012 analysis of federally funded trials on ClinicalTrials.gov found that 46% had published results.

ClinicalTrials.gov is a global register and the world’s largest. Information from the trials registered on it is used to make prescribing decisions every day around the world. So information from those trials is vital for regulators and researchers making decisions about  treatments currently available to patients.

There’s no excuse for not publishing results but a huge public health benefit to having a complete picture of what was found in trials. We are facing on opportunity now to make sure this situation doesn’t continue. The EU Clinical Trials Regulation will be debated in Brussels next week. It contains proposals that would ensure all clinical trials conducted in Europe are registered before they begin and results from them are made publicly available within a year of their end. Please write to your Health Minister today and ask them to ensure this good progress isn’t lost.

The Guardian, Scientists voice fears over ethics of drug trials remaining unpublished

Nature, ‘Ethical failure’ leaves one-quarter of all clinical trials unpublished