ANTIMICROBIAL USE AND RESISTANCE IN 8 US HOSPITALS - COMPLEXITIES OF ANALYSIS AND MODELING

OBJECTIVE: To evaluate the relation between antimicrobial use and resi stance in intensive-care unit (ICU) and non-ICU inpatient areas in eig ht US hospitals.METHODS: We determined antimicrobial use in terms of d efined daily doses, antimicrobial-use density (defined daily doses/1,0 00 patient days), and percentage resistance for five antimicrobial-org anism combinations in the ICU and non-ICU inpatient areas of eight US hospitals participating in project Intensive Care Antimicrobial Resist ance Epidemiology. RESULTS: Antimicrobial resistance and use varied tr emendously among the eight hospitals. Antimicrobial resistance among t hese five nosocomial pathogens was significantly higher within the inp atient setting of these hospitals, compared with the outpatient settin g. One hospital consistently ranked highest for use of all classes of antimicrobials examined. High antimicrobial use was not associated nec essarily with high resistance for a particular antimicrobial-organism pair. CONCLUSION: Antimicrobial use varied significantly across these hospitals, but generally was higher in ICUs. These results suggest tha t concomitant surveillance of both antimicrobial resistance and antimi crobial use is helpful in interpreting antimicrobial resistance in a h ospital or ICU and that further analysis is required to determine the role of variables other than antimicrobial use in a statistical model for predicting antimicrobial resistance.