The study was carried out at University College Hospital (UCH), in Ibadan, Southwestern Nigeria. The hospital was established in 1957. It has 53 service and clinical departments and runs 75 consultative outpatient clinics per week in 45 specialty and sub-specialty disciplines. The hospital has 31 wards and a total bed capacity of 817. Inpatients admissions exceed 10,000 while outpatient clinic attendance approximate to over 17,000 a year. There is an antiretroviral clinic located within the hospital.