1. Department of Advanced Nursing Science, University of Venda, Private Bag X, Thohoyandou 0950, South Africa
2. Department of Work and Social Psychology, Maastricht University, Minderbroedersberg 6, 6211 LK Maastricht, The Netherlands
3. Department of Health Studies, University of South Africa, Pretoria 0003, South Africa
4. Department of Health Promotion, Maastricht University, Minderbroedersberg 6, 6211 LK Maastricht, The Netherlands