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Multicenter Study
. 2008 Jul;52(1):48-58.e2.
doi: 10.1016/j.annemergmed.2008.01.003. Epub 2008 Mar 17.

Risk prediction with procalcitonin and clinical rules in community-acquired pneumonia

David T Huang  1 , Lisa A Weissfeld, John A Kellum, Donald M Yealy, Lan Kong, Michael Martino, Derek C Angus; GenIMS Investigators
Affiliations
Multicenter Study

Risk prediction with procalcitonin and clinical rules in community-acquired pneumonia

David T Huang et al. Ann Emerg Med. 2008 Jul.

Abstract

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.

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Figures

Figure 1
Figure 1. Flow diagram of study
Figure 2
Figure 2. Kaplan-Meier survival curves, by PSI Class and procalcitonin tier
In PSI Class I–III, mortality was low, and stratification by procalcitonin tier did not provide additional information. In PSI Class IV/V, patients with a procalcitonin < 0.1 ng/mL had the lowest 30-day mortality. PSI – Pneumonia Severity Index. PCT – procalcitonin.
Figure 3
Figure 3. Kaplan-Meier survival curves, by CURB-65 Group and procalcitonin tier
In CURB-65 Group 1 patients, mortality was low, and and stratification by procalcitonin tier did not provide additional information. In CURB-65 Groups 2/3, patients with a procalcitonin < 0.1 ng/mL had the lowest 30-day mortality. PCT – procalcitonin.
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References

    1. DeFrances CJ, Podgornik MN. 2004 National Hospital Discharge Survey. Adv Data. 2006;(371):1–19. - PubMed
    1. Niederman MS, McCombs JS, Unger AN, et al. The cost of treating community-acquired pneumonia. Clinical Therapeutics. 1998;20(4):820–837. - PubMed
    1. Angus DC, Linde-Zwirble WT, Lidicker J, et al. Epidemiology of severe sepsis in the United States: Analysis of incidence, outcome, and associated costs of care. Crit Care Med. 2001;29(7):1303–1310. - PubMed
    1. Kaplan V, Angus DC, Griffin MF, et al. Hospitalized community-acquired pneumonia in the elderly: Age- and sex-related patterns of care and outcome in the United States. Am J Respir Crit Care Med. 2002;165(6):766–772. - PubMed
    1. Fine MJ, Auble TE, Yealy DM, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. 1997;336(4):243–250. - PubMed

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