Abstract
BACKGROUND: This study aimed to optimize risk prediction of severe community-acquired pneumonia (CAP) in children through age-stratified selection of albumin-based inflammatory ratios. METHODS: This retrospective study analyzed 1,071 pediatric CAP patients (aged 1-12 years). Propensity score matching (1:2 severe-to-mild ratio) within three age strata (1-3 years, 4-6 years, 7-12 years) generated balanced cohorts (N = 360). Neutrophil percentage-to-albumin ratio (NPAR), C-reactive protein-to-albumin ratio (CAR), and CRP × lymphocyte-to-albumin ratio (CALLY) were evaluated using multivariate logistic regression and ROC analysis. RESULTS: Severe CAP incidence increased with age (1-3 years: 7.37%; 4-6 years: 12.80%; 7-12 years: 18.04%). Multivariate analysis identified NPAR as the sole independent predictor for younger children (1-3 years: OR = 10.289; 4-6 years: OR = 35.117), while CAR predicted severe CAP in older children (7-12 years: OR = 3.342). ROC analysis demonstrated robust performance for NPAR in 1-6 years (AUC: 0.748-0.807, NPV: 85.9-88.0%) and CAR in 7-12 years (AUC: 0.734, NPV: 83.0%). CONCLUSIONS: NPAR (for ages 1-6 years) and CAR (for ages 7-12 years) serve as effective, age-specific biomarkers for severe CAP, facilitating precise risk stratification with high negative predictive value.