1. Department of Community Medicine, Institute of Health and Society, University of Oslo, P.O. Box 1130 Blindern, 0318 Oslo, Norway
2. Faculty of Nursing, Kamuzu College of Nursing, University of Malawi, Blantyre Campus, P.O. Box 415, Blantyre, Malawi
3. Faculty of Nursing, Kamuzu College of Nursing, University of Malawi, Lilongwe Campus, Private Bag 1, Lilongwe, Malawi