Improving antibiotic use in the hospital: Focusing on positive blood cultures is an effective option.

The unsolicited and systematic evaluation of positive blood cultures (pBC) after laboratory report by a single infectious disease specialist (IDS) was evaluated during one year, using a computer-generated alert by the laboratory. The main objectives of IDS counselling were to improve antibiotic use for bloodstream infection (i.e., initiating or modifying therapy) and to stop unjustified therapy for contaminated pBC.During the first part of the study (4 months), all pBC in patients from ICUs, medical and surgical wards were analyzed. After an interim analysis, only pBC from medical and surgical wards were evaluated during the second part (8 months).Overall, 1090 episodes of pBC (representing 866 patients) were evaluated and classified as bloodstream infection (65.5%), contamination (29%) or undetermined (5.5%). Forty-three percent of episodes prompted IDS counselling, including initiation (5%), modification (27.5%), withdrawal (3.5%) and diagnosis workup (5%). Restricting the evaluation to medical and surgical wards increased the rate of counselling (61.2% vs. 27.7%, P<0.0001), notably for de-escalating (20% vs. 8%, P<0.0001), initiating (9% vs. 2%, P<0.0001), oral switch (6% vs. 2%, P<0.0001), withdrawing (5% vs. 2%, P=0.002) or reducing the duration of therapy (5% vs. 2%, P=0.002).In complement to the laboratory report, a computer-generated alert used by the IDS was useful for the management of pBC in hospital. The impact of IDS counselling was more effective when the evaluation was restricted to medical and surgical wards.