title: Using the number needed to treat to assess appropriate antimicrobial therapy as a determinant of outcome in severe sepsis and septic shock.
abstract: OBJECTIVE
  To assess appropriate antimicrobial therapy as an outcome determinant in severe sepsis and septic shock using the number needed to treat.
  
  
  METHODS
  Single-center cohort study (January 2008 to December 2012).
  
  
  METHODS
  One thousand two hundred fifty-bed academic hospital.
  
  
  METHODS
  Two thousand five hundred ninety-four patients with positive blood culture.
  
  
  METHODS
  We retrospectively identified patients with severe sepsis or septic shock. Inappropriate antimicrobial treatment was defined as an antimicrobial regimen that lacked in vitro activity against the isolated pathogen. Information regarding demographics, severity of illness, comorbidities, microbiology, and antimicrobial treatment was recorded. Logistic regression was used to identify risk factors for hospital mortality and inappropriate treatment.
  
  
  RESULTS
  Seven hundred eighty-seven patients (30.3%) were nonsurvivors. Inappropriate antimicrobial treatment had the greatest adjusted odds ratio for hospital mortality (adjusted odds ratio, 3.4; 95% CI, 2.8-4.1; p < 0.001). Multivariate logistic regression analysis identified resistance to cefepime, resistance to meropenem, presence of multidrug resistance, nonabdominal surgery, and prior antibiotic use as being independently associated with the administration of inappropriate antimicrobial treatment. For the entire cohort, the number needed to treat with appropriate antimicrobial therapy to prevent one patient death was 4.0 (95% CI, 3.7-4.3). The prevalence-adjusted pathogen-specific number needed to treat (PNNT) with appropriate antimicrobial therapy to prevent one patient death was lowest for multidrug-resistant bacteria (PNNT = 20) followed by Candida species (PNNT = 34), methicillin-resistant Staphylococcus aureus (PNNT = 38), Pseudomonas aeruginosa (PNNT = 38), Escherichia coli (PNNT = 40), and methicillin-susceptible S. aureus (PNNT = 47).
  
  
  CONCLUSIONS
  Our results support the importance of appropriate antimicrobial treatment as a determinant of outcome in patients with severe sepsis and septic shock. Our analyses suggest that improved targeting of empiric antimicrobials for multidrug-resistant bacteria, Candida species, methicillin-resistant S. aureus, and P. aeruginosa would have the greatest impact in reducing mortality from inappropriate antimicrobial treatment in patients with severe sepsis and septic shock.
authors: 1Division of Infectious Diseases, University of New Mexico, Albuquerque, NM. 2Pulmonary and Critical Care Division, Washington University School of Medicine, St. Louis, MO. 3School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA. 4Pulmonary and Critical Care Division, Washington Hospital Center, Washington, D.C. 5Division of Pharmacy Practice, St. Louis College of Pharmacy, St. Louis, MO.
authors: Cristina
authors: C
authors: Vazquez-Guillamet
authors: Michael
authors: M
authors: Scolari
authors: Marya D
authors: MD
authors: Zilberberg
authors: Andrew F
authors: AF
authors: Shorr
authors: Scott T
authors: ST
authors: Micek
authors: Marin
authors: M
authors: Kollef
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000302:isolation & purification; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D016015:Logistic Models; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D018805:Sepsis / Q000097:blood / Q000188:drug therapy* / Q000401:mortality*; D012772:Shock, Septic / Q000097:blood / Q000188:drug therapy / Q000401:mortality; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents