Optimising antimicrobial drug use in surgery: an intervention study in a Dutch university hospital.

Following a one-month prospective study of antimicrobial drug use in surgical departments, new guidelines were implemented. The review was repeated after two years. In both study periods, one third of patients were prescribed antimicrobial drugs. Prophylactic antibiotic consumption decreased from 0.75 to 0.53 defined daily doses/operation. Compliance with guidelines improved from 32% to 79%. Duration of prophylaxis > 24 h decreased from 21% to 8%. Single dose prophylaxis increased from 34% to 80%. Quality of the prophylactic courses improved, as evaluated by experts using established criteria. For prophylaxis, cost savings amounted to 57%. Better quality of therapeutic courses was associated with a cost increase of 15%. Indicators of satisfactory outcome with the new policy were a stable median length of stay (5.5 days in the first review and 5.0 days after intervention) and a reduction in the number of nosocomial infections treated with antimicrobial drugs/100 bed days (1.0 before intervention vs 0.77 after intervention).