Intensification of antibiotic use within acute care hospitals in the Netherlands

To report and analyse trends in antibiotic use in Dutch university hospitals, large teaching hospitals and general hospitals over the period 2003 to 2009. Data on the use of antibiotics and hospital resource indicators were obtained by distributing a questionnaire to all Dutch hospital pharmacies. Antibiotic use was expressed as the number of defined daily doses (DDDs) per 100 patient-days, per 100 admissions and per 1000 inhabitants per day. The latter was achieved by extrapolating sample data by means of imputation and up-scaling. From 2003 to 2009, the mean length of hospital stay decreased from 6.27 to 4.50 days (-28%). Total systemic antibiotic use significantly increased from 52.3 to 69.8 DDDs per 100 patient-days (P