Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12879-018-3156-z/MediaObjects/12879_2018_3156_Fig2_HTML.png)
Charlson’s comorbidity index (CCI) influences final outcome. a ROC curve of CCI for 28-day mortality. b Prognostic performance of CCI more than 2 for 28-day mortality. NPV: negative predictive value; PPV: positive predictive value; Se: sensitivity; Sp: specificity