Sarah Macfarlane is Emerita Professor in the Department of Epidemiology and Biostatistics and the Institute of Global Health Sciences at the University of California San Francisco in the United States. She has collaborated with individuals and institutions worldwide to build health information, surveillance and statistical systems. Carla AbouZahr is a senior technical adviser to the Bloomberg Data for Health Initiative at the University of Melbourne, Australia. Her career in global health includes over 20 years with the World Health Organization working with country and international partners to strengthen health information systems.