1 Department of Hygiene and Epidemiology, School of Medicine, University of Ioannina, Ioannina, Greece. Electronic address: christos.chalitsios@uoi.gr.
2 Department of Hygiene and Epidemiology, School of Medicine, University of Ioannina, Ioannina, Greece; Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.
3 Department of Hygiene and Epidemiology, School of Medicine, University of Ioannina, Ioannina, Greece; Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK; BHF Centre of Excellence, School of Public Health, Imperial College London, London, UK.