1. Department of Surgery, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology , Kumasi , Ghana
2. Surgery Unit, University Hospital, Kwame Nkrumah University of Science and Technology , Kumasi , Ghana
3. Department of Surgery, University of Washington , Seattle, Washington , USA
4. Harborview Injury Prevention and Research Center , University of Washington, Seattle, Washington , USA
5. Department of Epidemiology and Biostatistics, School of Public Health, Kwame Nkrumah University of Science and Technology , Kumasi , Ghana