Using two scores for the prediction of mortality in pediatric intensive care units

Abstract

Background Pediatric intensive care unit (PICU) has a specific location for the management of seriously ill children. Aim of the work The purpose of the study was to compare two models [Pediatric Risk of Mortality III (PRISM III) and the Pediatric Index of Mortality 3 (PIM3) scores] for the prediction of mortality in PICU in KSA. Patients and methods A prospective, cohort study was conducted and two mortality scores, PRISM III and PIM3, were applied on 68 children admitted to the PICU at As-Salama Hospital, Al Khobar, KSA over a period of 1 year from January till December 2016. Results The mean age was 7.6±5.3 years with more men than women and the mean length of hospital stay was 9.8±7.0 days. The overall expected mortality using the PRISM III score was 6.7% whereas that by PIM3 was 7.4% and the observed mortality was 17.6%. Both tests underpredicted mortality at all probability levels. However, the degree of underprediction was less when the predicted mortality was more than 25%. Both tests showed excellent discrimination with a value of 0.94 (95% confidence interval, 0.86–1.0) with 94.1% sensitivity and 72.0% specificity; and of 0.93 (95% confidence interval, 0.87–0.99) with 82.4% sensitivity and 84.0% specificity, respectively. The Hosmer and Lemeshow goodness-of-fit test showed good calibration for PRISM III score (χ2=4.57, P=0.148) but poor calibration for PIM3 score (χ2=8.66, P=0.01). Conclusion Both PRISM III and PIM3 scores underpredicted mortality at all probability levels. They offered good discrimination; however, the performance of the scoring system in the PICU patients was poor. PRISM III score showed good calibration while PIM3 score showed poor calibration.