1 Bart's and the London School of Medicine and Dentistry, London, UK.
2 Grupo de Investigación Biomedicina, Faculty of Medicine, Fundación Universitaria Autónoma de las Américas, Pereira, Risaralda, Colombia; Department of Clinical Epidemiology and Biostatistics, Universidad Científica del Sur, Lima, Perú; School of Medicine, Universidad Privada Franz Tamayo (UNIFRANZ), Cochabamba, Bolivia.
3 Professor of Epidemiology & Public Health Director of ISPM, Netherlands.