1 Department of Clinical Medicine, University of Bergen, Bergen, Norway.
2 Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.
3 Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway.
4 Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom. Electronic address: j.w.holloway@soton.ac.uk.