Rodríguez, Alejandro H.Avilés Jurado, Francesc XavierDíaz, EmiliSchuetz, PhilippTrefler, Sandra I.Solé Violán, JordiCordero, LourdesVidaur, LoretoEstella, ÁngelPozo Laderas, Juan CarlosSocias, LorenzoVergara, Juan C.Zaragoza, RafaelBonastre, JuanGuerrero, José EugenioSuberviola, BorjaCillóniz, CatiaRestrepo, Marcos I.Martín Loeches, IgnacioSEMICYUC/GETGAG Working Group2019-11-122019-11-122016-020163-4453https://hdl.handle.net/2445/144567Objectives: 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 <0.29 ng/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 <0.29 ng/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.9 p.application/pdfengcc-by-nc-nd (c) The British Infection Association, 2016http://creativecommons.org/licenses/by-nc-nd/3.0/esInfluenzavirusPèptidsInfluenza virusesPeptidesinfo:eu-repo/semantics/article6737582019-11-12info:eu-repo/semantics/openAccess280471626702737