Pediatric hospitalizations associated with 2009 pandemic influenza A (H1N1) in Argentina.

BACKGROUND: While the Northern Hemisphere experiences the effects of the 2009 pandemic influenza A (H1N1) virus, data from the recent influenza season in the Southern Hemisphere can provide important information on the burden of disease in children. METHODS: We conducted a retrospective case series involving children with acute infection of the lower respiratory tract or fever in whom 2009 H1N1 influenza was diagnosed on reverse-transcriptase polymerase-chain-reaction assay and who were admitted to one of six pediatric hospitals serving a catchment area of 1.2 million children. We compared rates of admission and death with those among age-matched children who had been infected with seasonal influenza strains in previous years. RESULTS: Between May and July 2009, a total of 251 children were hospitalized with 2009 H1N1 influenza. Rates of hospitalization were double those for seasonal influenza in 2008. Of the children who were hospitalized, 47 (19%) were admitted to an intensive care unit, 42 (17%) required mechanical ventilation, and 13 (5%) died. The overall rate of death was 1.1 per 100,000 children, as compared with 0.1 per 100,000 children for seasonal influenza in 2007. (No pediatric deaths associated with seasonal influenza were reported in 2008.) Most deaths were caused by refractory hypoxemia in infants under 1 year of age (death rate, 7.6 per 100,000). CONCLUSIONS: Pandemic 2009 H1N1 influenza was associated with pediatric death rates that were 10 times the rates for seasonal influenza in previous years.

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.

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.

Validation of the Pediatric Index of Mortality 2 (PIM2) in Argentina: a prospective, multicenter, observational study.

INTRODUCTION: The Pediatric Index of Mortality 2 (PIM2) is one of the most commonly used scoring systems to predict mortality in patients admitted to pediatric intensive care units (PICU) in Argentina. The objective of this study was to validate the PIM2 score in PICUs participating in the Quality of Care Program promoted by the Argentine Society of Intensive Care. POPULATION AND METHODS: Multicenter, prospective, observational, cross-sectional study. All patients between 1 month and 16 years old admitted to participating PICUs between January 1st, 2009 and December 31st, 2009 were included. The discrimination and calibration of the PIM2 score were assessed in the entire population and in different subgroups (risk of mortality, age, diagnoses on admission). RESULTS: Two thousand, eight hundred and thirty-two patients were included. PIM2 predicted 246 deaths; however, 297 patients died (p < 0.01). The standardized mortality ratio was 1.20 (95% confidence interval [CI]: 1.01-1.43). The area under the ROC curve was 0.84 (95% CI: 0.82-0.86). Statistically significant differences were detected between the observed and the predicted mortality for the entire population and for the different risk intervals (χ2: 71.02, df: 8, p < 0.001). Statistically significant differences were also found between observed and predicted mortality in adolescent patients (37/22, p = 0.03) and in those hospitalized due to respiratory disease (105/81, p = 0.03). CONCLUSIONS: The PIM2 score adequately discriminates survivors from non-survivors. However, it underscores the overall risk of death, especially in adolescent patients and those hospitalized due to respiratory disease. It is critical to take such differences into account when interpreting results.

Validación del índice pediátrico de mortalidad 2 (PIM2) en Argentina: un estudio prospectivo, multicéntrico, observacional / Validation of the Pediatric Index of Mortality 2 (PIM2) in Argentina: a prospective, multicenter, observational study

Introducción. El índice pediátrico de mortalidad 2 (Pediatric Index of Mortality 2; PIM2, por sus siglas en inglés) es uno de los puntajes más utilizados para la predicción de la mortalidad en pacientes ingresados en las Unidades de Cuidados Intensivos Pediátricos (UCIP) argentinas. El objetivo de este estudio fue validar el puntaje PIM2 en las UCIP integrantes del Programa de Calidad de Atención de la Sociedad Argentina de Terapia Intensiva. Población y métodos. Estudio multicéntrico, prospectivo, observacional, de corte transversal. Se incluyeron todos los pacientes de entre 1 mes y 16 años de edad, ingresados en las UCIP participantes entre el 01-01-2009 y el 31-122009. Se evaluó la discriminación y calibración del puntaje PIM2 en toda la población y en diferentes subgrupos (riesgo de mortalidad, edad, diagnósticos de ingreso). Resultados. Se incluyeron 2832 pacientes. El PIM2 predijo 246 muertes; sin embargo, fallecieron 297 pacientes (p <0,01). La razón de mortalidad estandarizada fue 1,20 (IC 95%: 1,01-1,43). El área bajo la curva ROC fue 0,84 (IC 95%: 0,82-0,86). Se detectaron diferencias estadísticamente significativas entre las muertes observadas y las predichas para toda la población y en los distintos intervalos de riesgo (χ² 71,02; df 8; p <0,001). También se detectaron diferencias estadísticamente significativas entre las muertes observadas y esperadas en los pacientes adolescentes (37/22, p= 0,03) y en aquellos ingresados con patología respiratoria (105/81, p= 0,03). Conclusiones. El puntaje PIM2 permite diferenciar adecuadamente los pacientes que sobreviven de aquellos que fallecen. Sin embargo, subvalora el riesgo de muerte en forma global, especialmente en los pacientes adolescentes y en aquellos ingresados por causa respiratoria. Es fundamental considerar estas diferencias al interpretar los resultados.

Introduction. The Pediatric Index of Mortality 2 (PIM2) is one of the most commonly used scoring systems to predict mortality in patients admitted to pediatric intensive care units (PICU) in Argentina. The objective of this study was to validate the PIM2 score in PICUs participating in the Quality of Care Program promoted by the Argentine Society of Intensive Care.Population and Methods. Multicenter, prospective, observational, cross-sectional study.All patients between 1 month and 16 years old admitted to participating PICUs between January 1st, 2009 and December 31st, 2009 were included. The discrimination and calibration of the PIM2 score were assessed in the entire population and in different subgroups (risk of mortality, age, diagnoses on admission).Results. Two thousand, eight hundred and thirty-two patients were included. PIM2 predicted 246 deaths; however, 297 patients died (p < 0.01). The standardized mortality ratio was 1.20 (95% confidence interval [CI]: 1.01-1.43). The area under the ROC curve was 0.84 (95% CI: 0.82-0.86). Statistically significant differences were detected between the observed and the predicted mortality for the entire population and for the different risk intervals (χ²: 71.02, df: 8, p < 0.001). Statistically significant differences were also found between observed and predicted mortality in adolescent patients (37/22, p = 0.03) and in those hospitalized due to respiratory disease (105/81, p = 0.03).Conclusions. The PIM2 score adequately discriminates survivors from non-survivors. However, it underscores the overall risk of death, especially in adolescent patients and those hospitalized due to respiratory disease. It is critical to take such differences into account when interpreting results.