title: Impact of appropriate antimicrobial therapy on mortality associated with Acinetobacter baumannii bacteremia: relation to severity of infection.
abstract: BACKGROUND
  The efficacy of antimicrobial therapy for Acinetobacter baumannii bacteremia has been difficult to establish because of confounding by underlying diseases, severity of infection, and differences in the pathogenicity of Acinetobacter species. This retrospective study was conducted to evaluate the effect of appropriate antimicrobial therapy on 14-day mortality after adjustment for multiple risk factors.
  
  
  METHODS
  The population consisted of 252 patients with monomicrobial A. baumannii bacteremia admitted to a large teaching hospital in Taiwan. The isolates were identified to species level using reference molecular methods. Predictors of 14-day mortality were determined by logistic regression analysis. The influence of severity of infection, determined by Acute Physiology and Chronic Health Evaluation (APACHE) II score, on the impact of appropriate use of antimicrobials on 14-day mortality was assessed by including an interaction term.
  
  
  RESULTS
  The overall 14-day mortality rate was 29.8% (75 of 252 patients). The unadjusted mortality rate for appropriate antimicrobial therapy was 13.2% (12 of 91 patients). Appropriate therapy was independently associated with reduced mortality (odds ratio [OR], 0.22; 95% confidence interval [CI], .01-.50; P < .001), and the effect was influenced by APACHE II score (OR for interaction term, 0.90; 95% CI, .82-.98; P= .02). A subgroup analysis revealed that the benefit of appropriate therapy was limited to patients with high APACHE II scores (OR for patients with scores >25 and ≤ 35, 0.16 [95% CI, .07-.37]; OR for those with scores >35, 0.06; 95% CI, .01-.25).
  
  
  CONCLUSIONS
  Appropriate antimicrobial therapy significantly reduced 14-day mortality for A. baumannii bacteremia in severely ill patients.
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yi-Tzu
authors.initials: YT
authors.lastname: Lee
authors.forename: Shu-Chen
authors.initials: SC
authors.lastname: Kuo
authors.forename: Su-Pen
authors.initials: SP
authors.lastname: Yang
authors.forename: Yi-Tsung
authors.initials: YT
authors.lastname: Lin
authors.forename: Fan-Chen
authors.initials: FC
authors.lastname: Tseng
authors.forename: Te-Li
authors.initials: TL
authors.lastname: Chen
authors.forename: Chang-Phone
authors.initials: CP
authors.lastname: Fung
mesh_terms: D018806:APACHE; D000151:Acinetobacter Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality* / Q000473:pathology; D040981:Acinetobacter baumannii / Q000472:pathogenicity*; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality* / Q000473:pathology; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013624:Taiwan; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents