• Open Access

Can procalcitonin tests aid in identifying bacterial infections associated with influenza pneumonia? A systematic review and meta-analysis

Authors

  • Meng-Huan Wu,

    1. Department of Emergency Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
    2. Chang Gung University College of Medicine, Taoyuan, Taiwan
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  • Chi-Chun Lin,

    1. Chang Gung University College of Medicine, Taoyuan, Taiwan
    2. Department of Emergency Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan
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  • Shiau-Ling Huang,

    1. Department of Emergency Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
    2. Chang Gung University College of Medicine, Taoyuan, Taiwan
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  • Hong-Mo Shih,

    1. Chang Gung University College of Medicine, Taoyuan, Taiwan
    2. Department of Emergency Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan
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  • Chung-Cheng Wang,

    1. Department of Emergency Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
    2. Chang Gung University College of Medicine, Taoyuan, Taiwan
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  • Chien-Chang Lee,

    1. Department of Emergency Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan
    2. Department of Emergency Medicine, National Taiwan University Hospital Yunlin Branch, Douliou, Taiwan
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  • Jiunn-Yih Wu

    1. Chang Gung University College of Medicine, Taoyuan, Taiwan
    2. Department of Emergency Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan
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Jiunn-Yih Wu, 3F, No.3,Ln. 325, Sec. 2, Shipai Rd, Beitou Dist, Taipei City 11267, Taiwan. E-mail: asepsis.wu@msa.hinet.net
Chien-Chang Lee, No.95, 19th Neighborhood, Lianshih, Huwei Township, Yunlin County 63247, Taiwan. E-mail: cclee100@gmail.com

Abstract

Objective  To summarize evidence for the diagnostic accuracy of procalcitonin (PCT) tests for identifying secondary bacterial infections in patients with influenza.

Methods  Major databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched for studies published between January 1966 and May 2009 that evaluated PCT as a marker for diagnosing bacterial infections in patients with influenza infections and that provided sufficient data to construct two-by-two tables.

Results  Six studies were selected that included 137 cases with bacterial coinfection and 381 cases without coinfection. The area under a summary ROC curve was 0·68 (95% CI: 0·64–0·72). The overall sensitivity and specificity estimates for PCT tests were 0·84 (95% CI: 0·75–0·90) and 0·64 (95% CI: 0·58–0·69), respectively. These studies reported heterogeneous sensitivity estimates ranging from 0·74 to 1·0. The positive likelihood ratio for PCT (LR+ = 2·31; 95% CI: 1·93–2·78) was not sufficiently high for its use as a rule-in diagnostic tool, while its negative likelihood ratio was reasonably low for its use as a rule-out diagnostic tool (LR− = 0·26; 95% CI: 0·17–0·40).

Conclusions  Procalcitonin tests have a high sensitivity, particularly for ICU patients, but a low specificity for identifying secondary bacterial infections among patients with influenza. Because of its suboptimal positive likelihood ratio and good negative likelihood ratio, it can be used as a suitable rule-out test but cannot be used as a standalone rule-in test.

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