1 Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Porto, Portugal; Institute of Public Health, University of Porto (ISPUP), Porto, Portugal.
2 Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Porto, Portugal; Faculty of Medicine, Eduardo Mondlane University, Maputo, Mozambique.
3 Faculty of Medicine, Eduardo Mondlane University, Maputo, Mozambique.