Surveillance of antibiotic use in hospitals: methods, trends and targets.

A standardised antibiotic surveillance system is an essential requirement of all antibiotic control strategies. Antibiotic use can be quantified accurately using patient-level surveillance, although this is not feasible for most hospitals. Instead, population-level surveillance is a more realistic alternative for ongoing and systematic monitoring of antibiotic use. Monitoring of aggregate, ward-supply data on a monthly basis, stratification by patient care area, and analysis by the anatomical therapeutic chemical/defined daily dose (ATC/DDD) system, adjusting for bed-occupancy, provides a clear picture of antibiotic consumption density and time-trends within a hospital. When usage rates are supplemented and interpreted according to changes in hospital resource indicators, benchmarking is facilitated. This provides an efficient tool for triggering and targeting antibiotic control interventions.