1. Department of Pediatrics, Alberta Research Centre for Health Evidence, University of Alberta, Edmonton, Alberta, Canada;
2. Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada;
3. Department of Pediatrics and Child Health, Winnipeg, Manitoba, Canada;
4. Department of Epidemiology and Community Medicine, Ottawa Methods Centre, Clinical Epidemiology Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada;
5. Department of Paediatrics, University of Calabar, Nigeria;
6. Texas Children's Hospital, Houston, Texas;
7. Faculty of Nursing, University of Alberta and Alberta Heritage Foundation for Medical Research, Edmonton, Alberta, Canada;
8. Clinical Epidemiology Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada; and
9. Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada