Acute physiology and chronic health evaluation II score is a better predictor of mortality than IBMP-10 in patients with ventilator-associated pneumonia.

Background: The (Immunodeficiency, Blood pressure [<90 mm Hg], Multilobular intiltrates [chest x-ray], Platelets [<100×10⁹/L], hospitalization [<10 days] before the onset of ventilator-associated pneumonia [VAP]) IBMP-10 is a new scoring system proposed as an easy-to-use alternative to the Acute Physiology and Chronic Health Evaluation II (APACHE II) score for predicting mortality in patients with ventilator-associated pneumonia (VAP). The objective of this study was to determine the validity of the IBMP-10 score compared with APACHE II in predicting mortality for an independent population consisting predominantly of surgical and neurotrauma patients.

Methods: The IBMP-10 and APACHE II scores on the day of VAP diagnosis were calculated, and areas under the receiver-operating characteristic curves (AUROCs) were compared to determine the tests' abilities to predict 14- and 28-day mortality.

Results: A total of 168 patients meeting the radiologic and clinical criteria for VAP for a single hospitalization between 2004 and 2007 were included; 80% of these were from the surgical or neurotrauma intensive care unit. Overall mortality rates were 15% and 23% at 14 and 28 days, respectively. The AUROC for the IMBP-10 score for predicting 14-day mortality was 0.609 (p=0.084) compared with 0.648 (p=0.017) for the APACHE II score. Both IBMP-10 and APACHE II AUROCs for predicting 14-day mortality were lower than observed in the original score validation (0.808 and 0.743, respectively). The AUROCs for predicting 28-day mortality were 0.602 (p=0.056) and 0.705 (p<0.001) for IBMP10 and APACHE II, respectively.

Conclusions: The IBMP-10 score was less reliable than the APACHE II score in predicting 14-day mortality in this independent population of VAP patients. This finding highlights the need for additional validation of new disease severity scoring systems in a study population independent of the population used to derive score criteria, as well as in more specific populations of critically ill patients.