title: Obesity Is Not Associated with Antimicrobial Treatment Failure for Intra-Abdominal Infection.
abstract: BACKGROUND
  Obesity and commonly associated comorbidities are known risk factors for the development of infections. However, the intensity and duration of antimicrobial treatment are rarely conditioned on body mass index (BMI). In particular, the influence of obesity on failure of antimicrobial treatment for intra-abdominal infection (IAI) remains unknown. We hypothesized that obesity is associated with recurrent infectious complications in patients treated for IAI.
  
  
  METHODS
  Five hundred eighteen patients randomized to treatment in the Surgical Infection Society Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial were evaluated. Patients were stratified by obese (BMI ≥30) versus non-obese (BMI≥30) status. Descriptive comparisons were performed using Chi-square test, Fisher exact test, or Wilcoxon rank-sum tests as appropriate. Multivariable logistic regression using a priori selected variables was performed to assess the independent association between obesity and treatment failure in patients with IAI.
  
  
  RESULTS
  Overall, 198 (38.3%) of patients were obese (BMI ≥30) versus 319 (61.7%) who were non-obese. Mean antibiotic d and total hospital d were similar between both groups. Unadjusted outcomes of surgical site infection (9.1% vs. 6.9%, p = 0.36), recurrent intra-abdominal infection (16.2% vs. 13.8, p = 0.46), death (1.0% vs. 0.9%, p = 1.0), and a composite of all complications (25.3% vs. 19.8%, p = 0.14) were also similar between both groups. After controlling for appropriate demographics, comorbidities, severity of illness, treatment group, and duration of antimicrobial therapy, obesity was not independently associated with treatment failure (c-statistic: 0.64).
  
  
  CONCLUSIONS
  Obesity is not associated with antimicrobial treatment failure among patients with IAI. These results suggest that obesity may not independently influence the need for longer duration of antimicrobial therapy in treatment of IAI versus non-obese patients.
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Zachary C
authors.initials: ZC
authors.lastname: Dietch
authors.affiliation: 3 Department of Surgery, Virginia Commonwealth University , Richmond, Virginia.
authors.forename: Therese M
authors.initials: TM
authors.lastname: Duane
authors.affiliation: 4 Department of Surgery, Beth Israel Deaconess Medical Center , Boston, Massachusetts.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Cook
authors.affiliation: 5 Department of Surgery, Maricopa Integrated Health System , Phoenix, Arizona.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: O'Neill
authors.affiliation: 6 Department of Surgery, Brigham and Women's Hospital , Boston, Massachusetts.
authors.forename: Reza
authors.initials: R
authors.lastname: Askari
authors.affiliation: 7 Department of Surgery, University of Michigan , Ann Arbor, Michigan.
authors.forename: Lena M
authors.initials: LM
authors.lastname: Napolitano
authors.affiliation: 8 Department of Surgery, University of Miami Miller School of Medicine , Miami, Florida.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Namias
authors.affiliation: 9 Department of Surgery, University of South Carolina , Columbia, South Carolina.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Watson
authors.affiliation: 10 Department of Surgery, University of Texas Health Science Center at San Antonio , San Antonio, Texas.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Dent
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Brandy L
authors.initials: BL
authors.lastname: Edwards
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Puja M
authors.initials: PM
authors.lastname: Shah
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Guidry
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Davies
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Rhett N
authors.initials: RN
authors.lastname: Willis
authors.affiliation: 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.|2 Division of Patient Outcomes, Policy and Population Research, Department of Public Health Sciences, The University of Virginia Health System , Charlottesville, Virginia.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Sawyer
mesh_terms: D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D015992:Body Mass Index; D004334:Drug Administration Schedule; D006801:Humans; D059413:Intraabdominal Infections / Q000188:drug therapy*; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D012008:Recurrence; D012044:Regression Analysis; D017211:Treatment Failure
chemical_list: D000890:Anti-Infective Agents