Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2007 Jul;57(540):555-60.

Procalcitonin versus C-reactive protein for predicting pneumonia in adults with lower respiratory tract infection in primary care

Anette Holm  1 , Svend S Pedersen, Joergen Nexoe, Niels Obel, Lars P Nielsen, Ole Koldkjaer, Court Pedersen
Affiliations
Comparative Study

Procalcitonin versus C-reactive protein for predicting pneumonia in adults with lower respiratory tract infection in primary care

Anette Holm et al. Br J Gen Pract. 2007 Jul.

Abstract

Background: The role of procalcitonin in diagnosing bacterial infection has mainly been studied in patients with severe infections. There is no study on the value of procalcitonin measurements in adults with lower respiratory tract infection (LRTI) treated in primary care.

Aim: To evaluate the accuracy of plasma procalcitonin in predicting radiographic pneumonia, bacterial infection, and adverse outcome in a population of adults with LRTI treated in primary care.

Design of study: Prospective, observational study.

Setting: Forty-two general practices and an outpatient clinic at the Department of Infectious Diseases, Odense University Hospital, Denmark.

Method: A total of 364 patients with LRTI were prospectively enrolled from 42 general practices. Patients were examined with chest radiography, microbiological analyses, and measurements of C-reactive protein (CRP) and procalcitonin. The outcome measure was hospitalisation within 4 weeks of enrollment.

Results: Median procalcitonin was 0.05 ng/ml, which was below the functional sensitivity of the assay (0.06 ng/ml). In predicting radiographic pneumonia, bacterial infection, and hospitalisation, the sensitivities of procalcitonin >0.06 ng/ml were 0.70, 0.51, and 0.67, and of CRP were > or =20 mg/l, 0.73, 0.56, and 0.74 respectively. Corresponding positive predictive values were between 0.09 and 0.28.

Conclusion: Both procalcitonin >0.06 ng/ml and CRP > or =20 mg/l were associated with radiographic pneumonia, bacterial infection, and subsequent hospitalisation, but positive predictive values were too low for any of the two inflammatory markers to be of use in clinical practice. To measure procalcitonin values accurately in the primary care setting, a more sensitive method is needed, but there was no indication that procalcitonin is superior to CRP in identifying patients with pneumonia, bacterial aetiology, or adverse outcome.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Receiver operating characteristic (ROC) curves of procalcitonin and C-reactive protein (CRP) predicting radiographic pneumonia.
Figure 2
Figure 2
Receiver operating characteristic (ROC) curves of procalcitonin and C-reactive protein (CRP) predicting bacterial aetiology.
Figure 3
Figure 3
Receiver operating characteristic (ROC) curves of procalcitonin and C-reactive protein (CRP) predicting hospitalisation.
See this image and copyright information in PMC

Comment in

References

    1. Raherison C, Peray P, Poirier R, et al. Management of lower respiratory tract infections by French general practitioners: the AIR II study. Analyse Infections Respiratoires. Eur Respir J. 2002;19(2):314–319. - PubMed
    1. Huchon GJ, Gialdroni-Grassi G, Leophonte P, et al. Initial antibiotic therapy for lower respiratory tract infection in the community: a European survey. Eur Respir J. 1996;9(8):1590–1595. - PubMed
    1. Gonzales R, Barrett PH, Jr, Crane LA, Steiner JF. Factors associated with antibiotic use for acute bronchitis. J Gen Intern Med. 1998;13(8):541–548. - PMC - PubMed
    1. Metlay JP, Kapoor WN, Fine MJ. Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical examination. JAMA. 1997;278(17):1440–1445. - PubMed
    1. Plouffe JF, McNally C, File TM., Jr Value of noninvasive studies in community-acquired pneumonia. Infect Dis Clin North Am. 1998;12(3):689–699. ix. - PubMed

Publication types