Broad-spectrum antibiotics (BSAs) are costly and prone to misuse. Their use is associated with the emergence of resistant bacteria. This article describes the first step of an interhospital programme for the appropriate use of BSAs.
BSAs were defined as the i.v. antibiotics present in the formulary shared by the six participating institutions and considered to be antipseudomonal agents (i.e. cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem, piperacillin/tazobactam) plus trovafloxacin. Annual utilisation rates and interhospital comparisons were provided to each institution using the "defined daily dosages" (DDDs) of the World Health Organization.
From 1997 to 1999, the overall utilisation rate of BSAs increased from 20.6 treatment days (TD)/1000 patient days (PD) to 36.5 TD/1000 PD. Significant interhospital differences were detected (range: 12.1 TD/1000 PD in 1997-66.5 TD/1000 PD in 1999). The highest relative risk for treatment with any BSA for each individual hospital in comparison to the others was determined for 1999 (RR = 2.92; 95% confidence interval: 2.81-3.04). In 1999, the most frequently used BSAs were cefepime, imipenem, and piperacillin/tazobactam respectively.
Although this programme does not provide information on the indications for using BSAs in various hospitals, it helps to identify those institutions where the selection pressure for resistant bacteria is highest, and that could particularly benefit from specific interventions aiming at decreasing this pressure and controlling drug expenditure. Moreover, the feedback of utilisation rates and interhospital comparisons to the prescribing physicians might have a positive impact on BSA use.