Several findings from Argentina provide compelling evidence of the need for more rational use of antimicrobial agents. Thus, a multidisciplinary antimicrobial treatment committee for the development of a hospital-wide intervention program was formed to optimize the quality of antibiotic use in hospitals. Four successive steps were developed during 6-month periods: baseline data collection, introduction of a prescription form, education, and prescribing control. Sustained reduction of drug consumption was shown during the study (R2=0.6885; P=.01). Total cost savings was 913,236 US dollars. To estimate the consumption of cefepime and aminopenicillin-sulbactam in relation to that of the third-generation cephalosporins, 2 indices were calculated: Icfp and Iams, respectively. Decreasing resistance to ceftriaxone by Proteus mirabilis and Enterobacter cloacae proved to be associated with increasing Icfp. Decreasing rates of methicillin-resistant Staphylococcus aureus were related to increasing Iams. The present study indicates that a systematic program performed by a multidisciplinary team is a cost-effective strategy for optimizing antibiotic prescribing.

We have previously observed a significant reduction of ceftriaxone resistance in Proteus mirabilis associated with an increase in the use of cefepime, along with a decrease in the consumption of broad-spectrum cephalosporins (CEP). However, we did not observe such a reduction with Klebsiella pneumoniae. Therefore, we sought to determine whether replacement of CEP by piperacillin-tazobactam might be useful in reducing sustained high rates of CEP resistance by this organism. We used a 6-month "before and after model"; during the second (intervention) period, most prescriptions of CEP were changed to piperacillin-tazobactam at the pharmacy. No additional barrier precautions were undertaken. During intervention, consumption of ceftazidime decreased from 17.73 to 1.14 defined daily doses (DDD) per 1,000 patient-days (P < 0.0001), whereas that of piperacillin-tazobactam increased from 0 to 30.57 DDD per 1,000 patient-days (P < 0.0001). The levels of resistance to CEP by K. pneumoniae and P. mirabilis decreased from 68.4 and 57.9% to 37.5 and 29.4%, respectively (P < 0.05). We conclude that replacement of ceftazidime by piperacillin-tazobactam might be a suitable strategy to decrease endemic CEP resistance by K. pneumoniae and P. mirabilis, even where there are high bacterial resistance rates and irrespective of any additional precautions for controlling nosocomial infection.

Our results illustrate that a reduction in antibiotic consumption does not always represent a favorable outcome from an intervention program on prescribing practice. Moreover, it may be a sensitive indirect marker of a deficient healthcare condition leading to an increase in in-hospital mortality.

We recently published on the impact of a four-phase hospital-wide intervention program designed to optimize the quality of antibiotic use, where a multidisciplinary team (MDT) could modify prescription at the last phase. Because health care quality was changing during the last 5 years (late 1999 to early 2004), we developed certain indicators to monitor the quality of our intervention over time. Different periods were defined as baseline (pre-intervention), initial intervention-active control, pre-crisis control, crisis control, post-crisis control and end of crisis control. Major indicators were rates of prescription modification by the MDT; prescription for an uncertain infection and a novel index formula (RIcarb) to estimate the rationale for carbapenem use. We assessed 2115 antimicrobial prescriptions. Modification of prescription rate was 30% at the beginning and decreased thereafter up to stable levels. Rate of prescriptions ordered for cases of both uncertain infection and unknown source of infection decreased significantly after intervention (i.e. from baseline to active control). In contrast, a doubling of culture-directed prescriptions was observed between these periods. RIcarb values lower and higher than 60% (modal, cut-off) were assumed as carbapenem overuse and underuse, respectively. Overuse was observed at the pre-intervention, while pronounced underuse was shown during the crisis (RIcarb, 45% and 87%, respectively). The present study demonstrates that certain indicators, other than the widely adopted impact outcomes, are a suitable tool for monitoring the quality of a continuous, long-term, active intervention on antimicrobial prescribing practice, especially when applied in a changing healthcare setting.