Can mass media interventions reduce child mortality?

Many people recognise that mass media is important in promoting public health but there have been few attempts to measure how important. An ongoing trial in Burkina Faso (ClinicalTrials.gov, NCT01517230) is an attempt to bring together the very different worlds of mass media and epidemiology: to measure rigorously, using a cluster-randomised design, how many lives mass media can save in a low-income country, and at what cost. Application of the Lives Saved Tool predicts that saturation-based media campaigns could reduce child mortality by 10-20%, at a cost per disability-adjusted life-year that is as low as any existing health intervention. In this Viewpoint we explain the scientific reasoning behind the trial, while stressing the importance of the media methodology used.