Modified guidelines impact on antibiotic use and costs: duration of treatment for pneumonia in a neurosurgical ICU is reduced.

Objectives: To evaluate the impact of an intervention to reduce the duration of antibiotic treatment for pneumonia in a neurosurgical intensive care unit (ICU). The usage of antibiotics and the resultant costs were examined using interrupted time series analysis while resistance and device-associated infection rates are also described.
Methods: In January 2004, revised guidelines for the use of antibiotics were implemented. As a consequence of this, the duration of antibiotic therapy for nosocomial pneumonia was reduced from 14 to 7 days, while for community-acquired pneumonia the period fell from 10 to 5 days. The effect on the antibiotic use density [AD; expressed as defined daily doses (DDD) per 1000 patient days (pd)] was calculated by segmented regression analysis of interrupted time series for the 24 months prior to (2002 and 2003) and after the intervention (2004 and 2005).
Results: The intervention was associated with a significant decrease in total AD from 949.8 to 626.7 DDD/1000 pd after the intervention. This was mainly due to reduced consumption of second-generation cephalosporins (-100.6 DDD/1000 pd), imidazoles (- 100.3 DDD/1000 pd), carbapenems (-33.3 DDD/1000 pd), penicillins with beta-lactamase inhibitor (-33.5 DDD/1000 pd) and glycopeptides (-30.2 DDD/1000 pd). Glycopeptide reduction might be associated with a significant decrease in the proportion of methicillin-resistant Staphylococcus aureus (8.4% before and 2.9% after the intervention). Similarly, total antibiotic costs/pd (Euro) showed a significant decrease from 13.16 Euro/pd before to 7.31 euro/pd after the intervention. This is a saving of 5.85 Euro/pd. The incidence of patients dying with pneumonia did not change significantly.
Conclusions: The most conservative estimate of segmented regression analysis over a 48 month period showed that halving the duration of treatment for pneumonia results in a reduction of over 30% in antibiotic consumption and costs. Because respiratory infections are most common in ICU patients, interventions targeting a reduction in the duration of treatment of pneumonia might be extremely worthwhile.