Moving toward the reduction of publication/reporting biases in clinical trials using a new international standard

Evidence-based medicine (EBM) is fundamental to ensuring high-quality medical care. It requires systematic reviews and meta-analyses to synthesize diverse information available from individual clinical studies. However, the literature reviewed may represent an incomplete and selective set of research findings, which could lead to publication/reporting biases and distort the true picture of research as a whole. Prospective registry of all clinical trials in the world is mandatory to reduce the biases, which have been disclosed on the International Clinical Trials Registry Platform (ICTRP) of the World Health Organization (WHO) since 2007. The Japan Primary Registries Network (JPRN) is included in the ICTRP. ClinicalTrials.gov, the U.S. clinical trial registry, reports the standardized data of registered trials and offers access to submitted outcomes online. However, the JPRN does not systematically include the outcomes. On April 14, 2015, the WHO published a new statement online on the public disclosure of clinical trial results, which requires researchers to define the timeframes of reporting main findings and key outcomes, to call for results-reporting older, but still unpublished trials, and to outline steps to improve linkages between clinical trial registry entries and their published results. The WHO's new position will facilitate global efforts to reduce publication/reporting biases in clinical trials. Japan will have to actively participate in these efforts as well.