Validation of Pediatric Index of Mortality 3 for Predicting Mortality among Patients Admitted to a Pediatric Intensive Care Unit

Background: The objective of this study was to evaluate the usefulness of the newest version of the pediatric index of mortality (PIM) 3 for predicting mortality and validating PIM 3 in Korean children admitted to a single intensive care unit (ICU). Methods: We enrolled children at least 1 month old but less than 18 years of age who were admitted to the medical ICU between March 2009 and February 2015. Performances of the pediatric risk of mortality (PRISM) III, PIM 2, and PIM 3 were evaluated by assessing the area under the receiver operating characteristic (ROC) curve, conducting the Hosmer-Lemeshow test, and calculating the standardized mortality ratio (SMR). Results: In total, 503 children were enrolled; the areas under the ROC curve for PRISM III, PIM 2, and PIM 3 were 0.775, 0.796, and 0.826, respectively. The area under the ROC curve was significantly greater for PIM 3 than for PIM 2 (P<0.001) and PRISM III (P=0.016). There were no significant differences in the Hosmer-Lemeshow test results for PRISM III (P=0.498), PIM 2 (P=0.249), and PIM 3 (P=0.337). The SMR calculated using PIM 3 (1.11) was closer to 1 than PIM 2 (0.84). Conclusions: PIM 3 showed better prediction of the risk of mortality than PIM 2 for the Korean pediatric population admitted in the ICU.