Pediatric Index of Mortality 2 as a predictor of death risk in children admitted to pediatric intensive care units in Latin America: A prospective, multicenter study

Abstract

Purpose: The purpose of this study is to asses the performance of the Pediatric Index of Mortality 2 (PIM2) score in pediatric intensive care units (PICUs) in Latin America.

Materials and methods: This is a prospective, observational, multicenter study. We included patients aged 1 month to 16 years old admitted consecutively during 1 year to 34 PICUs in 9 Latin American countries. Discrimination and calibration tests were performed to validate the performance of PIM2 in the entire sample and in different subgroups.

Results: A total of 7391 patients were analyzed. Pediatric Index of Mortality 2 predicted 573 deaths, whereas the observed deaths were 663 (P < .001). The area under the receiver operating characteristic curve for the entire population was 0.817 (95% confidence interval, 0.808-0.825). The score showed good discrimination. Instead, calibration was inadequate. The difference between observed and predicted deaths for the entire population and across different risk intervals was statistically significant (χ(2) = 121.87; df = 8; P < .001). Pediatric Index of Mortality 2 did not predict mortality correctly in different diagnostic categories (injury, postoperative, and miscellaneous), in children younger than 12 months, adolescents, and patients with chronic complex conditions.

Conclusions: Pediatric Index of Mortality 2 showed good discrimination, but calibration was inadequate. To use PIM2 for monitoring PICU performance in Latin America, it might be necessary to recalibrate the score locally.

Keywords: Benchmarking; Mortality; Outcome assessment (health care); Pediatric intensive care unit; Pediatrics; Risk assessment.