1. Department of Public Health, Vrije Universiteit Brussel,
Laarbeeklaan 103, 1090 Brussels, Belgium, pdelobel@vub.ac.be
2. Health Promotion Unit, School of Public Health, University
of Limpopo, Private Bag X1106, Sovenga 0699, South Africa
3. Department of Public Health, Vrije Universiteit Brussel,
Laarbeeklaan 103, 1090 Brussels, Belgium