Associations Between Systemic Immunity Inflammation Index, Aggregate Index of Systemic Inflammation, and Hospital Acquired Otitis Media in Children Aged ≤12 years with Bacterial Pneumonia

Purpose: Hospital-acquired otitis media (OM) is a common complication in children with bacterial pneumonia, associated with prolonged morbidity. Systemic inflammation indices (SII and AISI) may serve as biomarkers for OM risk. This study aimed to evaluate the association of SII and AISI with hospital-acquired OM risk in children (≤ 12 years) with bacterial pneumonia. Patients and Methods: A total of 388 children (aged ≤ 12 years) diagnosed with bacterial pneumonia were enrolled in this study from January 2024 to June 2025.. Data included demographic characteristics, birth history, feeding history, and laboratory tests. Logistic regression analysis was used to analyze the relationship between SII, AISI, and the risk of OM. This study constructed a nomogram prediction model, and the performance of the model was assessed by the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA). Results: The majority of patients were male (54.90%) and aged ≤ 3 years (55.93%). Based on OM status, children were divided into No-OM group (n = 289) and OM group (n = 99). The OM group showed significantly elevated levels of inflammatory markers (WBC, NEU, MON, PLT, CRP, SII and AISI), alongside lower levels of RBC, HGB, and TP, compared to the No-OM group (all p 0.05), with inflection points at 9.71 (log2-SII) and 8.16 (log2-AISI). Conclusion: This study established the predictive value of SII and AISI for hospital acquired OM in children aged ≤ 12 years with bacterial pneumonia. Integrating them into clinical practice can guide targeted prevention and thereby improve prognosis. Keywords: systemic immunity inflammation index, aggregate index of systemic inflammation, bacterial pneumonia, otitis media, inflammation