Surveillance of monthly antimicrobial consumption rates stratified by patient-care area: a tool for triggering and targeting antibiotic policy changes in the hospital.

The profile and temporal trends of antimicrobial use were investigated at a university hospital. Aggregate data were analyzed according to the ATC/DDD methodology. During 1998-2002, hospital-wide antimicrobial use increased by 22%, from 86.97 to 106.24 defined daily doses per 100 bed-days [DDD/100BD]. Pooled usage rates in DDD/100BD, overall percentage increases and annual average increase rates were respectively 109.97, 35.6%, 8.1 for Medical wards, 98.21, 48.7%, 9.1 for Intensive Care Units and 74.46, 34.3%, 5.7 for Hemato-oncology wards. Surgical wards had a fairly constant usage rate (98.36). A shift towards the newer broad-spectrum antibiotics, to the detriment of the older penicillins and cephalosporins, was noted in all hospital areas. Surveillance of antimicrobial consumption using the ATC/DDD system provided a clear picture of its profile. Monthly rates over a sufficient surveillance period allowed the assessment of temporal trends. Stratification of rates according to clinical service allowed areas of concern to be specified and targeted antibiotic policy changes to be initiated.