Assessment of predictive efficacy for prognosis of pediatric severe Mycoplasma pneumoniae pneumonia: a comprehensive study based on high-resolution computed tomography imaging and platelet parameters.

BACKGROUND

Severe Mycoplasma pneumoniae pneumonia (SMPP) in children can be associated with persistent pulmonary abnormalities and delayed recovery, making early identification of patients at risk of an unfavorable post-discharge physiological outcome clinically important for follow-up planning. This study aimed to evaluate the associations of early high-resolution computed tomography (HRCT) findings and hematologic parameters with a 3-month Pediatric Critical Illness Score (PCIS)-defined physiological outcome in children with SMPP and to explore the internal performance of a parsimonious model combining complementary imaging and hematologic information.

METHODS

This secondary analysis used a publicly available, de-identified dataset containing 153 children with SMPP, of whom 39 had PCIS <80 three months after discharge. Distribution-appropriate comparative methods were used. Derived platelet ratios were excluded from primary model development to avoid redundancy with their component variables. A parsimonious logistic model incorporated lobar pneumonia, lung consolidation, and platelet count (PLT); PLT was modeled using a 3-knot restricted cubic spline because of evidence of nonlinearity. Internal validation used 1,000 bootstrap resamples. Discrimination, calibration, Brier score, and decision-curve analysis were evaluated.

RESULTS

Lobar pneumonia and lung consolidation were more frequent and PLTs were lower among children with PCIS <80. PLT showed a significant nonlinear association with the outcome. The model had an apparent area under the receiver operating characteristic curve (AUC) of 0.890 [95% bootstrap confidence interval (CI): 0.832-0.940] and an optimism-corrected AUC of 0.877. The apparent and optimism-corrected Brier scores were 0.117 and 0.129, respectively; the optimism-corrected calibration intercept was -0.041 and the calibration slope was 0.890.

CONCLUSIONS

Early HRCT abnormalities and PLT provided complementary information regarding a 3-month PCIS-defined physiological outcome in this severe-disease cohort. Because of the limited number of outcome events and the absence of external validation, the model should be considered exploratory and should not yet be used as a clinical decision rule.