Validation of an Electronic Pediatric Index of Mortality 2 Score in a Mixed Quaternary PICU

Area of Science:

• Pediatric critical care medicine
• Health informatics
• Clinical epidemiology

Background:

• The Pediatric Index of Mortality 2 (PIM2) score is a validated tool for assessing pediatric intensive care unit (PICU) patient mortality risk.
• Electronic health records (EHRs) offer a rich data source for clinical research, but require validated scoring systems for retrospective analysis.

Purpose of the Study:

• To assess the validity and accuracy of an electronic version of the Pediatric Index of Mortality 2 score (ePIM2) using retrospective EHR data.
• To determine if ePIM2 can reliably predict mortality in a mixed-ICU population.

Main Methods:

• A retrospective observational study was conducted in pediatric and cardiac ICUs.
• The PIM2 score was adapted for retrospective EHR data analysis.
• The ePIM2 was validated against manually ascertained PIM2 scores in 100 patients and assessed for discrimination, calibration, and accuracy in 12,582 patient encounters.

Main Results:

• Nine out of 11 PIM2 components showed good agreement (ICC or Cohen κ ≥ 0.6) between manual and electronic derivations.
• The ePIM2 demonstrated good discrimination (AUC = 0.89), appropriate calibration (no significant difference between observed and expected deaths), and excellent predictive ability (Brier score = 0.0135).

Conclusions:

• The electronic version of the Pediatric Index of Mortality 2 score is a valid and accurate tool for retrospective analysis of EHR data.
• ePIM2 can be reliably used for risk stratification and outcome prediction in large mixed-ICU cohorts.