Abstract: ObjectiveTo evaluate the ability of the pediatric critical illness score (PCIS) and the pediatric risk of mortality score Ⅲ (PRISM Ⅲ) in assessing the severity of the disease and the prognosis of children in intensive care unit (PICU). MethodsWe received continuous cases of PICU from Children's Hospital of Fudan University from July 21, 2016 to July 30, 2017. In PICU, PCIS and PRISM Ⅲ scores were obtained from the most abnormal recorded values of clinical data in the first 12 h. Cases were divided into the death groups, the transfer group and the automatic discharge group by PICU outcomes. Cases were divided into the non-survival group and the survival group by outcomes within 28 days after PICU (the cases in the automatic discharge group were followed up by telephone on the 28th day after PICU). The death subgroup of the automatic discharge group and the death group were the non-survival group; the survival subgroup of the automatic discharge group and the transfer group were the survival group. Age, the state before admission, the disease when entering the PICU, the source of the children, and the main cause, whether in the PICU received invasive mechanical ventilation treatment, PICU hospitalization time and other data were collected from medical history. Correlation analysis was done using Pearson correlation analysis, and logistic regression analysis was used to evaluate the predictive effect of each index on the outcomes of the two scoring systems. ResultsA total of 685 cases were included in the study. According to PICU outcomes, there were 100 cases in the death group, 442 cases in the transfer group, and 143 cases in the automatic discharge group. The following differences were statistically significant: age, pre-hospital status and PICU hospitalization time of the transfer group compared with the death group or the automatic discharge group; pre-hospital cardiopulmonary resuscitation of the death group compared with the automatic discharge group or the transfer group; the use of vasoactive drugs of the transfer group compared with the death group; trauma, tumor and other causes of the main cause in the automatic discharge group and the transfer group. According to the 28-day follow-up outcomes after PICU, the cases were divided into the non-survival group (n=218) and the survival group (n=467), including 118 cases of automatic discharge death subgroup and 25 cases of automatic discharge survival subgroup. Univariate analysis showed that respiratory rate, systolic blood pressure, pH, PaO2, and creatinine/urea nitrogen in the PCIS score were statistically different between the non-survival group and the survival group; systolic blood pressure, pH, acidosis, total content of CO2, PaO2, PaCO2, blood urea nitrogen, PT/APTT, PLT count and conscious state in the PRISM Ⅲ score were statistically different between the non-survival group and the survival group. ConclusionBoth PCIS and PRISM Ⅲ are suitable for the assessment of the severity of disease and the prognosis of children in PICU. Systolic blood pressure and pH have a greater effect on predicting outcomes of death and survival.