1. Faculty of Health Sciences, Stellenbosch University; Centre for Evidence-Based Health Care; Tygerberg South Africa
2. South African Medical Research Council; South African Cochrane Centre; PO Box 19070 Tygerberg Western Cape South Africa 7505
3. College of Medicine, University of Lagos; Department of Paediatrics and Child Health; Idi-Araba Surulere Lagos Lagos Nigeria PMB 12003