Impact of an assisted reassessment of antibiotic therapies on the quality of prescriptions in an intensive care unit.

Objectives: The study's objective was to assess the impact of a professional multifaceted intervention designed to improve the quality of inpatient empirical therapeutic antibiotic courses at the time of their reassessment, i.e. 24 to 96 hours after treatment initiation.

Design: We conducted a 5-month prospective pre- and post-intervention study in a medical Intensive Care Unit (ICU) in a teaching hospital, using time-series analysis. The intervention was a multifaceted professional intervention combining systematic 3-weekly visits of an infectious diseases specialist to discuss all antibiotic therapies, interactive teaching courses, and daily contact with a microbiologist.

Results: Eighty-one antibiotic prescriptions were assessed, 37 before and 44 after the intervention. The prevalence of adequate antibiotic prescriptions was high and not statistically different before and after the intervention (73% vs. 80%, P=0.31), both for sudden change (P=0.67) and linear trend (P=0.055), using interrupted time-series analysis. The intervention triggered a more frequent reassessment of the diagnosis between day 2 and day 4 (11% vs. 32%, P=0.02) and slightly improved the adaptation of antibiotic therapies to positive microbiology (25% before vs. 50% after, P=0.18).

Conclusions: Our multifaceted intervention may have improved the quality of antibiotic therapies around day 3 of prescription, but the difference did not reach statistical significance, possibly because of a ceiling effect.