1796. Does Timing of Receipt of Appropriate Antimicrobial Therapy Make a Difference Among Patients with Serious Infections due to Resistant Gram-negative Pathogens?
Session: Oral Abstract Session: Resistance is Futile
Saturday, October 29, 2016: 11:22 AM
Room: 288-290

Background: To examine the impact of timely vs delayed appropriate antimicrobial therapy among patients with serious infections due to resistant Gram-negative pathogens.

Methods: Using a US hospital database, we identified admissions of adults between July 1, 2011 and September 30, 2014 with evidence of serious infection. The date of the earliest positive culture for Gram-negative bacteria was deemed the “index date”, and all patients were required to have ≥1 resistant pathogens (i.e., carbapenem-resistant Enterobacteriaceae, multi-drug resistant Pseudomonas sp., carbapenem-resistant Pseudomonas sp., extended spectrum beta-lactamase-producing organisms) on this date. Antimicrobial therapy was defined as appropriate if all pathogens identified on index date were susceptible to ≥1 agents received. Receipt of appropriate therapy on index date or ≤2 days thereafter was deemed “timely”; receipt of such therapy subsequently, as “delayed”. We used multivariate regression models to compare the groups on total in-hospital costs, duration of antibiotic therapy and length of stay (LOS; days; index date to discharge).

Results: A total of 6055 patients met selection criteria; 2800 (46.2%) received delayed appropriate therapy. In multivariate analyses, and relative to patients who received timely appropriate therapy, those in whom such therapy was delayed averaged 3.7 more days of antibiotic therapy, 4.1 greater LOS days, and $7,587 greater total in-hospital costs (all P<0.01; Table). In both groups, room and board represented about 55% of total costs; antibiotics, only 3% (Figure).

Conclusion: Initiation of appropriate therapy ≤2 days of index culture is associated with shorter therapy duration, shorter LOS, and lower total in-hospital costs. Earlier identification methods for infection with resistant pathogens may shorten time to appropriate therapy, potentially improving outcomes in these patients.


Table. Mean (95% CI) multivariate-adjusted in-hospital outcomes and costs among hospitalized patients who received delayed vs timely appropriate therapy





Therapy duration, d

8.0 (7.9, 8.1)

11.7 (11.6, 11.9)


LOS, d

8.2 (8.1, 8.3)

12.3 (12.2, 12.4)


Total cost, $

17,857 (17,435, 18,290)

25,444 (24,794, 26,111)


Ariel Berger, MPH1, Tarun Bhagnani, MS1, Rosa Wang, MHA1, Qi Zhao, MD, MPH2, Michael Ye, MS2 and Thomas P. Lodise, PharmD, PhD3, (1)Evidera, Lexington, MA, (2)Allergan plc, Jersey City, NJ, (3)Albany College of Pharmacy and Health Sciences, Albany, NY


A. Berger, Evidera: Employee , Salary

T. Bhagnani, Evidera: Employee , Salary

R. Wang, Evidera: Employee , Salary

Q. Zhao, Allergan plc: Employee , Salary

M. Ye, Allergan plc: Employee , Salary

T. P. Lodise, Allergan/Merck/Medicines Company: Consultant and Speaker's Bureau , Consulting fee and Speaker honorarium

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