title: Procalcitonin guidance of antibiotic therapy in community-acquired pneumonia: a randomized trial.
abstract: BACKGROUND
  In patients with community-acquired pneumonia, guidelines recommend antibiotic treatment for 7 to 21 d. Procalcitonin is elevated in bacterial infections, and its dynamics have prognostic implications.
  
  
  OBJECTIVE
  To assess procalcitonin guidance for the initiation and duration of antibiotic therapy in community-acquired pneumonia.
  
  
  METHODS
  In a randomized intervention trial, 302 consecutive patients with suspected community-acquired pneumonia were included. Data were assessed at baseline, after 4, 6, and 8 d, and after 6 wk. The control group (n = 151) received antibiotics according to usual practice. In the procalcitonin group (n = 151), antibiotic treatment was based on serum procalcitonin concentrations as follows: strongly discouraged, less than 0.1 microg/L; discouraged, less than 0.25 microg/L; encouraged, greater than 0.25 microg/L; strongly encouraged, greater than 0.5 microg/L. The primary endpoint was antibiotic use; secondary endpoints were measures of clinical, laboratory, and radiographic outcome.
  
  
  RESULTS
  At baseline, both groups were similar regarding clinical, laboratory, and microbiology characteristics, and Pneumonia Severity Index. Procalcitonin guidance reduced total antibiotic exposure (relative risk, 0.52; 95% confidence interval, 0.48-0.55; p < 0.001), antibiotic prescriptions on admission (85 vs. 99%; p < 0.001), and antibiotic treatment duration (median, 5 vs. 12 d; p < 0.001) compared with patients treated according to guidelines. After adjustment for Pneumonia Severity Index, the hazard ratio of antibiotic discontinuation was higher in the procalcitonin group than in the control group (3.2; 95% confidence interval, 2.5 to 4.2). Outcome was similar in both groups, with an overall success rate of 83%.
  
  
  CONCLUSIONS
  Procalcitonin guidance substantially reduces antibiotic use in community-acquired pneumonia. These findings may have important clinical and public health implications.
authors.affiliation: Department of Internal Medicine, University Hospital, Basel, Switzerland. christmj@bluewin.ch
authors.forename: Mirjam
authors.initials: M
authors.lastname: Christ-Crain
authors.forename: Daiana
authors.initials: D
authors.lastname: Stolz
authors.forename: Roland
authors.initials: R
authors.lastname: Bingisser
authors.forename: Christian
authors.initials: C
authors.lastname: Müller
authors.forename: David
authors.initials: D
authors.lastname: Miedinger
authors.forename: Peter R
authors.initials: PR
authors.lastname: Huber
authors.forename: Werner
authors.initials: W
authors.lastname: Zimmerli
authors.forename: Stephan
authors.initials: S
authors.lastname: Harbarth
authors.forename: Michael
authors.initials: M
authors.lastname: Tamm
authors.forename: Beat
authors.initials: B
authors.lastname: Müller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D017714:Community-Acquired Infections / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy*; D011498:Protein Precursors / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide