Procalcitonin (PCT) levels for ruling-out bacterial coinfection in ICU patients with influenza: A CHAID decision-tree analysis.
J Infect. 2015 Dec 15;
Authors: Rodríguez AH, Avilés-Jurado FX, Díaz E, Schuetz P, Trefler BCs SI, Solé-Violán J, Cordero L, Vidaur L, Estella Á, Pozo Laderas JC, Socias L, Vergara JC, Zaragoza R, Bonastre J, Guerrero JE, Suberviola B, C C, Restrepo MI, Martín-Loeches I, SEMICYUC/GETGAG working group
OBJECTIVES: To define which variables upon ICU admission could be related to the presence of coinfection using CHAID (Chi-squared Automatic Interaction Detection) analysis.
METHODS: A secondary analysis from a prospective, multicentre, observational study (2009-2014) in ICU patients with confirmed A(H1N1)pdm09 infection. We assessed the potential of biomarkers and clinical variables upon admission to the ICU for coinfection diagnosis using CHAID analysis. Performance of cut-off points obtained was determined on the basis of the binominal distributions of the true (+) and true(-) results.
RESULTS: Of the 972 patients included, 196 (20.3%) had coinfection. Procalcitonin (PCT;ng/mL 2.4 vs. 0.5, p<0.001), but not C-reactive protein (CRP;mg/dL 25 vs. 38.5; p=0.62) was higher in patients with coinfection. In CHAID analyses, PCT was the most important variable for coinfection. PCT<0.29ng/mL showed high sensitivity (Se=88.2%), low Sp(33.2%) and high negative predictive value (NPV= 91.9%). The absence of shock improved classification capacity. Thus, for PCT <0.29ng/mL, the Se was 84%, the Sp 43% and an NPV of 94% with a post-test probability of coinfection of only 6%.
CONCLUSION: PCT has a high negative predictive value (94%) and lower PCT levels seems to be a good tool for excluding coinfection, particularly for patients without shock.
PMID: 26702737 [PubMed - as supplied by publisher]