Pediatric Index of Mortality and PIM2 Scores Have Good Calibration in a Large Cohort of Children from a Developing Country

OBJECTIVE Our objective was to validate the Pediatric Index of Mortality (PIM) and PIM2 scores in a large cohort of children from a developing country. DESIGN Prospective observational study. SETTING Pediatric intensive care unit of a tertiary care teaching hospital. PATIENTS All children aged <18 years admitted between June 2011 and July 2013. MEASUREMENTS AND MAIN RESULTS We evaluated the discriminative ability and calibration as measured by the area under the receiver operating characteristic (ROC) curves, the Hosmer-Lemeshow goodness-of-fit (GOF), and standardized mortality ratio (SMR), respectively. Of the 819 children enrolled, 232 (28%) died. The median (IQR) age of the study subjects was 4 years (0.8, 10). The major reasons for ICU admission as well as mortality were sepsis/severe sepsis. The area under ROC curves for PIM and PIM2 was 0.72 (95% CI: 0.67-0.75) and 0.74 (95% CI: 0.70-0.78), respectively. The goodness-of-fit test showed a good calibration across deciles of risk for the two scores with P values being >0.05. The SMR (95% CI) was 0.99 (0.85-1.15) and 1 (0.85-1.16) for PIM and PIM2, respectively. The calibration across different age and diagnostic subgroups was also good. CONCLUSION PIM and PIM2 scores had good calibration in our setup.