Does a reduction in antibiotic consumption always represent a favorable outcome from an intervention program on prescribing practice?

OBJECTIVES: In our hospital, a continuous intervention program aimed at optimizing the quality of antibiotic use was introduced by late 1999 and antibiotic consumption was a major outcome for assessment. However, healthcare conditions have been subject to change over the last five years, and a pronounced economic crisis in 2002 affected the availability of antibiotics. Therefore, we hypothesized that the consumption of these drugs could be a suitable indirect marker of the crisis. DESIGN: We performed segmented regression analysis between different periods. Variations in antibiotic consumption during periods corresponding to the four-phase intervention program (from 1999 to the first six months of 2001) were assumed to be 'intervention-induced', while those observed during the crisis period were considered as 'situation-enforced'. RESULTS: Whereas the intervention-induced (desirable) decrease of total antibiotic and carbapenem consumption proved to correlate with a decreased crude mortality rate during the control period prior to the crisis (R2, 0.82 and 0.91, respectively), the crisis-induced (undesirable) decrease in total antibiotic and carbapenem consumption correlated with an increased mortality during this phase (R2, 0.80 and 0.75, respectively). CONCLUSIONS: 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.

Replacement of broad-spectrum cephalosporins by piperacillin-tazobactam: impact on sustained high rates of bacterial resistance.

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.