1. Research Department, FOCOS Orthopaedic Hospital, P.O.Box KD 779 , Accra - Ghana
2. Department of Population, Family and Reproductive Health, School of Public Health, College of Health Sciences, University of Ghana , Legon, P.O. Box LG 118, Accra , Ghana
3. College of Nursing, University of Cincinnati , Cincinnati 45221, Ohio
4. Department of Biostatistics, School of Public Health, College of Health Sciences, University of Ghana , Legon, P.O. Box LG 118, Accra , Ghana