1 School of Public Health, The University of Sydney, Sydney, Australia.
2 The George Institute for Global Health, UNSW, Sydney, Australia.
3 Clinical Trial Service Unit and Epidemiological Studies Unit, Big Data Institute, University of Oxford, Old Road Campus, Oxford, OX3 7LF, UK.
4 The George Institute for Global Health at Peking University Health Science Center, Beijing, China.
5 Chinese Academy of Medical Sciences, Beijing, China.
6 The George Institute for Global Health, Oxford University, Oxford, UK.
7 Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA.
8 School of Public Health and Community Medicine, UNSW, Sydney, Australia.
9 Clinical Trial Service Unit and Epidemiological Studies Unit, Big Data Institute, University of Oxford, Old Road Campus, Oxford, OX3 7LF, UK. robert.clarke@ndph.ox.ac.uk.