Annals of Emergency Medicine
Volume 52, Issue 1 , Pages 48-58.e2, July 2008

Risk Prediction With Procalcitonin and Clinical Rules in Community-Acquired Pneumonia

Presented at the American College of Emergency Physicians Research Forum, October 2006, New Orleans, LA.

  • David T. Huang, MD, MPH

      Affiliations

    • Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
    • Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA
    • Corresponding Author InformationAddress for correspondence: David T. Huang, MD, MPH, Room 646B Scaife Hall, The CRISMA Laboratory, Department of Critical Care Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261; 412-647-6818, fax 412-647-3791
    • ,
  • Lisa A. Weissfeld, PhD

      Affiliations

    • Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
    • Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
    • ,
  • John A. Kellum, MD

      Affiliations

    • Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
    • ,
  • Donald M. Yealy, MD

      Affiliations

    • Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA
    • ,
  • Lan Kong, PhD

      Affiliations

    • Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
    • Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
    • ,
  • Michael Martino, MD

      Affiliations

    • Department of Emergency Medicine, Jefferson Regional Medical Center, Pittsburgh, PA.
    • ,
  • Derek C. Angus, MD, MPH

      Affiliations

    • Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
    • ,
  • GenIMS Investigators

Received 23 October 2007; received in revised form 21 December 2007; accepted 8 January 2008. published online 17 March 2008.

Study objective

The Pneumonia Severity Index and CURB-65 predict outcomes in community-acquired pneumonia but have limitations. Procalcitonin, a biomarker of bacterial infection, may provide prognostic information in community-acquired pneumonia. Our objective is to describe the pattern of procalcitonin in community-acquired pneumonia and determine whether procalcitonin provides prognostic information beyond the Pneumonia Severity Index and CURB-65.

Methods

We conducted a multicenter prospective cohort study in 28 community and teaching emergency departments. Patients presenting with a clinical and radiographic diagnosis of community-acquired pneumonia were enrolled. We stratified procalcitonin levels a priori into 4 tiers: I: less than 0.1; II: greater than 0.1 to less than 0.25; III: greater than 0.25 to less than 0.5; and IV: greater than 0.5 ng/mL. Primary outcome was 30-day mortality.

Results

One thousand six hundred fifty-one patients formed the study cohort. Procalcitonin levels were broadly spread across tiers: 32.8% (I), 21.6% (II), 10.2% (III), and 35.4% (IV). Used alone, procalcitonin had modest test characteristics: specificity (35%), sensitivity (92%), positive likelihood ratio (1.41), and negative likelihood ratio (0.22). Adding procalcitonin to the Pneumonia Severity Index in all subjects minimally improved performance. Adding procalcitonin to low-risk Pneumonia Severity Index subjects (classes I to III) provided no additional information. However, subjects in procalcitonin tier I had low 30-day mortality, regardless of clinical risk, including those in higher risk classes (1.5% versus 1.6% for those in Pneumonia Severity Index classes I to III versus classes IV/V). Among high-risk Pneumonia Severity Index subjects (classes IV/V), one quarter (126/546) were in procalcitonin tier I, and the negative likelihood ratio of procalcitonin tier I was 0.09. Procalcitonin tier I was also associated with lower burden of other adverse outcomes. Similar results were observed with CURB-65 stratification.

Conclusion

Selective use of procalcitonin as an adjunct to existing rules may offer additional prognostic information in high-risk patients.

 

 Supervising editors: Gregory J. Moran, MD; Judd E. Hollander, MD

 Dr. Moran and Dr. Hollander were the supervising editors on this article. Dr. Yealy did not participate in the editorial review or decision to publish this article.

 Author contributions: DTH, LAW, JAK, DMY, and DCA conceived and designed the study, analyzed and interpreted the data, and provided important critical revisions of the article. DTH, DMY and DCA drafted the article. DTH, JAK, DMY, and DCA provided final approval. LAW and LK provided statistical expertise. LAW also contributed to drafting of the article, and LK contributed to analysis and interpretation of the data. JAK and DCA obtained funding for the study. JAK, MM, and DCA provided administrative, technical, and logistic support. MM also contributed to analysis and interpretation of the data and article revision. DTH takes responsibility for the paper as a whole.

 Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article, that might create any potential conflict of interest. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Funding received from: NIGMS R01 GM061992. DTH, LAW, LK, DCA have provided consulting work to BRAHMS Diagnostica, the manufacturer of the procalcitonin assay used in this study. DTH has received one speaking honorarium and travel expenses for presentation at a satellite symposium of the September 2006 European Respiratory Society meeting in Munich, Germany. BRAHMS Diagnostica covered sample shipping and procalcitonin assay costs; no direct monetary grant support was provided.

 Publication dates: Available online March 17, 2008.

 Reprints not available from the authors.

PII: S0196-0644(08)00030-9

doi:10.1016/j.annemergmed.2008.01.003

Refers to article:

  • Risk Stratification of Community-Acquired Pneumonia: What Does All of This Mean? , 04 April 2008

    Alan E. Jones, Jeffrey A. Kline
    Annals of Emergency Medicine July 2008 (Vol. 52, Issue 1, Pages 61-62)

Annals of Emergency Medicine
Volume 52, Issue 1 , Pages 48-58.e2, July 2008

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