[1
]
Department of Epidemiology and Public Health, London School of Hygiene & Tropical
Medicine, London, UK.
[2
]
World Health Organization, Geneva, Switzerland.
[3
]
Centre of Medical Informatics, Usher Institute of Population Health Sciences and Informatics,
University of Edinburgh, Edinburgh EH8 9AG, UK. Electronic address: aziz.sheikh@ed.ac.uk.