29% of Large Clinical Trials results unpublished after 5 years

In the current issue of the British Medical Journal (BMJ), there is an article entitled, “Non-publication of large randomized clinical trials: cross sectional analysis” (BMJ2013;347:f6104). The authors examined clinical trials on clinicaltrials.gov to determine if data from these trials is available to the public. Databases PubMed, Google Scholar, and Embase were used to query for published results from trials registered with clinicaltrials.gov that had at least 500 participants and were completed prior to 2009. The authors found that 29% (171/585) of trials had no published results. More commonly, industry funded trials went unpublished than those not supported by industry (32% vs 18%). Seventy-eight percent had no data in clinicaltrials.gov. The authors concluded that 299,763 participants “were exposed to the risks of trial participation without the societal benefits that accompany the dissemination of trial results”.

Share This Post