Methods: Hospitalized adults with first episodes of gram-negative BSI from 2010-2013 at Palmetto Health Hospitals in Columbia, SC, USA were identified. Multivariate Cox proportional hazards regression was used to examine risk factors for prolonged HLOS following gram-negative BSI overall and within each predefined BSIMRS category (< 5 and ≥ 5).
Results: Among 830 unique patients with gram-negative BSI, 469 and 361 had BSIMRS < 5 and ≥ 5, respectively. Overall, median age was 65 years, 448 (54%) were women, and Escherichia coli was the most common organism 444 (54%). Variables that were independently associated with increased risk of remaining hospitalized following gram-negative BSI included BSIMRS (adjusted hazard ratio [aHR] 1.14 per point, 95% confidence interval [CI] 1.11-1.17, p<0.001) and inappropriate empirical antimicrobial therapy (aHR 1.41, 95% CI 1.07-1.91, p=0.01). After stratification based on BSIMRS, median HLOS with appropriate and inappropriate empirical antimicrobial therapy was 7 and 10 days, respectively, in patients with BSIMRS < 5 (p=0.03); and 13 and 17 days, respectively, in those with BSIMRS ≥ 5 (p=0.02).
Conclusion: Inappropriate empirical antimicrobial therapy is associated with prolonged HLOS in patients with gram-negative BSI at both ends of the spectrum of illness. This demonstrates benefit from appropriate empirical antimicrobial therapy in patients with BSIMRS < 5 and adds to previously described survival benefit in those with BSIMRS ≥ 5.
P. B. Bookstaver, Forest Labs: Grant Investigator and Scientific Advisor , Consulting fee
J. A. Justo, Cempra Pharmaceuticals: Scientific Advisor , Consulting fee
H. Albrecht, Gilead: Investigator and Scientific Advisor , Research grant
M. Al-Hasan, None