Abstract

    Introduction: Rapid advances in critical care technology and rising cost of medical care have spurred the development of outcome analysis including mortality risk prediction. Severity scoring systems integrate clinical data to estimate the probability of mortality, which can be used to facilitate resource utilization or continuing quality improvement and to stratify patients for clinical research. In spite of the development of specifics scores for pediatric populations in intensive care context and more, their effective validation at located realities, no validation evidences, in order to its application in Portuguese PICUs, have already been referenced.

    Aims: To assess and optimize the Pediatric Risk of Mortality (PRISM and PRISM III) and the Pediatric Index of Mortality (PIM and PIM2) scoring systems, in comparing the risk-adjusted mortality of children after admission in Portuguese Pediatric Intensive Care Units (PICUs).

    Design: Prospective, observational, analytical and multicenter study.

    Methods: Data was acquired from a database previously created in the context of a precursor project developed in the institution of filiation. The PRISM, PRISM III, PIM and PIM 2 scores of all patients included in the study were computed according to the published algorithms, and the outcome was noted in terms of survival or non-survival and compared with observed mortality, by Standardized Mortality Ratio (SMR). Mortality discrimination was quantified by calculating the area under the receiver operating characteristic (ROC) curve. Hosmer and Lemeshow goodness-of-fit test was used to assess scores calibration. To improve calibration of PIM2 prognostic model, a first-level customization was performed, using logistic regression on the original score, with base on Portuguese patients data, and the corresponding probability of PICU death was calculated for the customized score (C-PIM2).

    Results: One thousand and eight hundred and nine patients, with a mean age and male to female ratio of: 1.2:1, admitted at three volunteers Portuguese PICUs (Oporto, Coimbra, Lisbon), were enrolled. Hosmer-Lemeshow statistics showed good calibration for all original models, excepting PIM2, which displayed significant lack of fit and therefore poor calibrationtion (p=0,027). Discrimination was generally good for all models, with areas under the receiver operating characteristic curves (AUC) ranged from 0,84 (PIM) to 0,91 (PRISM III).

    Key words: Pediatric Intensive Care (MESH); Health quality (MESH); Clinical score (MESH); Mortality prediction (MESH); Validation (MESH).