Abstract
<title>Abstract</title> <p> Background The red cell distribution width-to-platelet count ratio (RPR), as a novel marker of inflammation and coagulation function, has been demonstrated to have prognostic value in various adult diseases; however, data on its prognostic role in the pediatric population remain limited. This study aimed to investigate the prognostic value of RPR levels in patients admitted to the Pediatric Intensive Care Unit (PICU). Methods This retrospective cohort study included 1,646 children admitted to the PICU. RPR values were calculated based on the first complete blood count (CBC) measured upon PICU admission, and patients were divided into four groups according to RPR quartiles: low (n = 409), low-medium (n = 384), medium-high (n = 438), and high (n = 415). Univariate and multivariate logistic regression analyses were sequentially performed to identify risk factors for in-hospital mortality. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive value of different markers, including RPR. Results The median age of the study population was 35.0 months (interquartile range: 7.1–83.0), and 58.7% were male. Compared with the medium-high, low-medium, and low RPR groups, patients in the high RPR group exhibited worse clinical outcomes ( <italic>P</italic> < 0.05). After adjusting for confounding factors in multivariate logistic regression analysis, RPR remained independently associated with in-hospital mortality (odds ratio[OR] = 1.37, 95% confidence interval[CI]:1.08–1.73, <italic>P</italic> < 0.05). ROC curve analysis confirmed that the area under the curve (AUC) for RPR alone was 0.724, with an optimal cut-off value of 0.037. Furthermore, a prediction model incorporating RPR and other indicators demonstrated better predictive performance (AUC = 0.907), with an optimal cut-off value of 0.058, a sensitivity of 82.8%, and a specificity of 83.8%. Conclusion RPR is significantly associated with mortality in PICU patients. A prediction model incorporating RPR is valuable for prognostic assessment in PICU patients, with an optimal early warning threshold of 0.037. Moreover, integrating RPR with other key indicators provides higher predictive accuracy. </p>