State-wide surveillance of in-hospital antimicrobial utilisation in South Australia

In late 2001, a group of South Australian metropolitan public and private hospitals commenced voluntary contribution of data on in-hospital utilisation of antimicrobials to the Communicable Disease Control Branch of the Department of Human Services. Where possible, hospitals contributed data on all antimicrobials dispensed for use within the institution each month. These data were stratified into antimicrobials issued to intensive care units and antimicrobials issued to all other areas within the hospital. In the first instance, only data relating to four antimicrobial classes have been analysed. These classes are third or fourth generation cephalosporins, carbapenems, glycopeptides and fluoroquinolones. Utilisation of these four classes was presented as a monthly utilisation rate i.e., total defined daily doses for each antimicrobial class per month per 1,000 occupied bed days. These utilisation rates were calculated for each individual hospital and for the combined group of contributing hospitals (state-wide rate). Although limited data are currently available, results to date demonstrate a much higher antimicrobial usage rate in intensive care units than other in-patient areas for the classes currently analysed. Considerable variation in the usage of various antimicrobials has been noted for individual hospitals, and analysis of trends over a longer time period, in conjunction with resistance surveillance data, will be required.