Open Medicine endorses PROSPERO.

Systematic reviews, which synthesize the data from individual studies, are considered the highest level of evidence for evaluating the effectiveness of health care interventions. They inform clinical practice guidelines and are used by health-policy makers to guide key decision-making. They can point to gaps in knowledge where new research is needed and provide knowledge about the saturation of evidence about effectiveness and where new research is not needed and indeed might be unethical (1). On February 22, 2011, the Centre for Reviews and Dissemination, University of York launched PROSPERO, an international prospective register of systematic review protocols. The registry was developed to address excessive duplication of systematic reviews, improve transparency and minimize reporting biases. Open Medicine endorses systematic review protocol registration at PROSPERO and encourages prospective authors to register their review protocols on health care interventions at http://www.metaxis.com/PROSPERO/ .