[1] Catholic Hosp, POB 2,via Sogakope, Battor, Volta, Ghana
[2] Univ Ottawa, Fac Med, Sch Epidemiol & Publ Hlth, Ottawa, ON K1H 8M5, Canada
[3] Inst Healthcare Improvement, State St,18th Floor, Boston, MA 02109 USA
[4] Univ Cape Coast, Cape Coast Teaching Hosp, Sch Med Sci, Dept Pathol, POB CT 1362, Cape Coast, Ghana