title: Impact of prior outpatient antibiotic use on mortality for community acquired pneumonia: a retrospective cohort study.
abstract: BACKGROUND
  The purpose of this study was to examine whether prior outpatient antibiotic use is associated with increased 30-day mortality, after adjusting for potential confounders, for those subsequently hospitalized with pneumonia.
  
  
  METHODS
  A retrospective cohort study conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of, and had a chest x-ray consistent with, community-acquired pneumonia. Our primary analysis was a multivariable logistic regression with the dependent variable of 30-day mortality.
  
  
  RESULTS
  Data was abstracted on 733 subjects at the two hospitals. Mortality was 8.1% at 30-days. At presentation, 55% of subjects were low risk, 33% were moderate risk, and 12% were high risk. In our cohort 17% (n = 128) of subjects received antibiotics within 30-days of presentation. Unadjusted mortality for those who had received prior antibiotics was 7.0% vs. 8.3% for those who had not (p = 0.6). In the multivariable analysis prior use of antibiotics (odds ratio 0.98, 95% confidence interval 0.5-2.1) was not significantly associated with 30-day mortality.
  
  
  CONCLUSIONS
  Receipt of prior outpatient antibiotics is not significantly associated with 30-day mortality for patients hospitalized with pneumonia. Our study supports current efforts to increase the number of patients with pneumonia who are treated as outpatients.
authors.affiliation: VERDICT Research Program, Audie L Murphy VA Hospital, 7400 Merton Minter Blvd (11C6), San Antonio, Texas, 78229, USA. mortensene@uthscsa.edu.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Mortensen
authors.forename: Marcos I
authors.initials: MI
authors.lastname: Restrepo
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Pugh
authors.forename: Antonio
authors.initials: A
authors.lastname: Anzueto