title: Evolution over a 15-year period of clinical characteristics and outcomes of critically ill patients with community-acquired bacteremia.
abstract: OBJECTIVE
  In recent years, outcomes for critically ill patients with severe sepsis have improved; however, no data have been reported about the outcome of patients admitted for community-acquired bacteremia. We aimed to analyze the changes in the prevalence, characteristics, and outcome of critically ill patients with community-acquired bacteremia over the past 15 yrs.
  
  
  METHODS
  A secondary analysis of prospective cohort studies in critically ill patients in three annual periods (1993, 1998, and 2007).
  
  
  METHODS
  Forty-seven ICUs at secondary and tertiary care hospitals.
  
  
  METHODS
  All adults admitted to the participating ICUs with at least one true-positive blood culture finding within the first 48 hrs of admission.
  
  
  METHODS
  None.
  
  
  RESULTS
  A total of 829 patients was diagnosed with community-acquired bacteremia during the study periods (148, 196, and 485 in the three periods). The prevalence density rate of community-acquired bacteremia increased from nine per 1000 ICU admissions in 1993 to 24.4 episodes per 1,000 ICU admissions in 2007 (p < 0.001). The prevalence of septic shock also increased from 4.6 episodes/1,000 admissions in 1993 to 14.6 episodes/1,000 admissions in 2007 (p < 0.001). Patients with community-acquired bacteremia were significantly older and had more comorbidities. No significant differences were observed in the presence of Gram-positive and Gram-negative micro-organisms among the three study periods. Mortality related to community-acquired bacteremia decreased over the three study periods: 42%, 32.2%, and 22.9% in 1993, 1998, and 2007, respectively (p < 0.01). The occurrence of septic shock and the number of comorbidities were independently associated with worse outcome. Appropriate antibiotic therapy and development of community-acquired bacteremia in 1998 and 2007 were independently associated with better survival.
  
  
  CONCLUSIONS
  The prevalence of community-acquired bacteremia in ICU patients has increased. Despite a higher percentage of more severe and older patients, the mortality associated with community-acquired bacteremia decreased. Improved management of severe sepsis might explain the improvements in outcomes.
authors.affiliation: Critical Care Center, Parc Taulí Hospital-Sabadell, UAB, CIBER enfermedades respiratorias, Sabadell, Spain. jvalles@tauli.cat
authors.forename: Jordi
authors.initials: J
authors.lastname: Vallés
authors.forename: Mercedes
authors.initials: M
authors.lastname: Palomar
authors.forename: Francisco
authors.initials: F
authors.lastname: Alvárez-Lerma
authors.forename: Jordi
authors.initials: J
authors.lastname: Rello
authors.forename: Armando
authors.initials: A
authors.lastname: Blanco
authors.forename: José
authors.initials: J
authors.lastname: Garnacho-Montero
authors.forename: Ignacio
authors.initials: I
authors.lastname: Martín-Loeches
mesh_terms: D017677:Age Distribution; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality / Q000628:therapy; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000628:therapy; D015897:Comorbidity; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D012772:Shock, Septic / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality / Q000628:therapy; D013030:Spain / Q000453:epidemiology; D016896:Treatment Outcome