P0158 / #274: COMPARISON ON PERFORMANCE OF THE PEDIATRIC INDEX OF MORTALITY (PIM) -2 AND PIM-3 SCORES IN THE PEDIATRIC CARE UNIT OF A HIGH COMPLEXITY INSTITUTION

Abstract

Aims & Objectives: To determine the performance of each of the available Pediatric Index of Mortality (PIM) scores, by assessing the capability for discrimination and calibration in patients admitted to a pediatric intensive care unit in the city of Bogotá. Methods: We designed a retrospective, observational cohort study, which included all patients aged between a month and 17 years and 364 days, admitted to the Pediatric Intensive Care Unit of a high complexity university hospital between April 1, 2016 and December 31, 2018. We analyzed the standardized mortality ratio, discrimination, calibration and net reclassification index (NRI) for each model. Results: A total of 722 patients were included, the mortality rate was 3.74 % and for PIM3 the ratio between expected and observed mortality was 0.66 (p = 0.01) for PIM2 and 1.00 (p = 0.99) for PIM3. The Hosmer-Lemeshow test suggests inadequate calibration for PIM2 (HL= 13.18 p = 0.11), but adequate calibration for PIM3 (HL = 28.08 p < 0.01). The area under the diagnostic performance curve for PIM2 was 0.87 (95% CI 0.80; 0.94), and 0.89 (95% CI 0.82; 0.95) for PIM3. The net reclassification index was -27.1 %. PIM 3 classified survivors better than PIM2, but inadequately classified non-survivors. Conclusions: Although both models show adequate discrimination ability, PIM3 shows a better correlation between predicted risk score and observed mortality. Thus, it may be a useful tool for measuring the internal processes of intensive care units in Colombia and for making comparisons between groups of similar characteristics.