Supplementary file 1_Prediction models for refractory Mycoplasma pneumoniae pneumonia and corticosteroid treatment escalation in hospitalized children: a retrospective cohort study.docx

No admission-day prediction tool has been validated to identify children at risk for either outcome.</p>Methods<p>Children admitted to a single tertiary centre with a diagnosis of MPP between January 2022 and June 2025 were enrolled in a retrospective cohort study. Two penalised logistic regression models were constructed from routine admission-day clinical and laboratory variables: one targeting RMPP occurrence across the full eligible cohort (Cohort A) and one targeting corticosteroid escalation within the treated subgroup (Cohort B).

Candidate predictors were screened by LASSO-penalised regression, and model performance was optimism-corrected via bootstrap resampling. Discrimination, calibration, and clinical utility were assessed by corrected AUC, calibration metrics, and decision curve analysis, with nomograms derived from the final coefficients.</p>Results<p>Of 383 Cohort A patients, 106 met criteria for RMPP. Within Cohort B (n = 197), 61 children (31.0%) required treatment escalation.