title: Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis.
abstract: BACKGROUND
  Procalcitonin is a promising marker for identification of bacterial infections. We assessed the accuracy and clinical value of procalcitonin for diagnosis of sepsis in critically ill patients.
  
  
  METHODS
  We searched Medline, Embase, ISI Web of Knowledge, the Cochrane Library, Scopus, BioMed Central, and Science Direct, from inception to Feb 21, 2012, and reference lists of identified primary studies. We included articles written in English, German, or French that investigated procalcitonin for differentiation of septic patients--those with sepsis, severe sepsis, or septic shock--from those with a systemic inflammatory response syndrome of non-infectious origin. Studies of healthy people, patients without probable infection, and children younger than 28 days were excluded. Two independent investigators extracted patient and study characteristics; discrepancies were resolved by consensus. We calculated individual and pooled sensitivities and specificities. We used I(2) to test heterogeneity and investigated the source of heterogeneity by metaregression.
  
  
  RESULTS
  Our search returned 3487 reports, of which 30 fulfilled the inclusion criteria, accounting for 3244 patients. Bivariate analysis yielded a mean sensitivity of 0 · 77 (95% CI 0 · 72-0 · 81) and specificity of 0 · 79 (95% CI 0 · 74-0 · 84). The area under the receiver operating characteristic curve was 0 · 85 (95% CI 0 · 81-0 · 88). The studies had substantial heterogeneity (I(2)=96%, 95% CI 94-99). None of the subgroups investigated--population, admission category, assay used, severity of disease, and description and masking of the reference standard--could account for the heterogeneity.
  
  
  CONCLUSIONS
  Procalcitonin is a helpful biomarker for early diagnosis of sepsis in critically ill patients. Nevertheless, the results of the test must be interpreted carefully in the context of medical history, physical examination, and microbiological assessment.
  
  
  BACKGROUND
  Ministry of Education and Research, the Deutsche Forschungsgemeinschaft, Thuringian Ministry for Education, Science and Culture, the Thuringian Foundation for Technology, Innovation and Research, and the German Sepsis Society.
authors: Department of Medical Statistics, Computer Sciences and Documentation, Centre for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
authors: Christina
authors: C
authors: Wacker
authors: Anna
authors: A
authors: Prkno
authors: Frank M
authors: FM
authors: Brunkhorst
authors: Peter
authors: P
authors: Schlattmann
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000378:metabolism; D002116:Calcitonin / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide; D016638:Critical Illness; D016208:Databases, Factual; D006801:Humans; D015995:Prevalence; D011498:Protein Precursors / Q000378:metabolism*; D012372:ROC Curve; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis* / Q000453:epidemiology; D018746:Systemic Inflammatory Response Syndrome / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide