2 Materials and methods
This study was carried out between June and August 1999 at Central Hospital, Benin City, Edo State, Nigeria. The hospital is centrally located and it is the largest hospital under the Edo State Hospitals Management Board. It has a large population of health personnel. The study design was a cross-sectional study. All doctors (n=60) and laboratory workers (n=34) at Central Hospital were included in the study. A total of 175 nurses were included in the study, this being 50% of the nurse population. This was based on the sample size calculation for comparative purposes. The nurses were selected using a stratified random sampling method. The nursing population was divided into groups or strata based on speciality practice areas such as paediatrics, surgical, medical wards, casualty and theatre. From each stratum, a sampling frame made up of nurses in each speciality area was constructed and the required sample size was selected using a table of random numbers. The sample fraction used in each stratum was (50%).