Early Corticosteroid Exposure and Hospital Mortality in Critically Ill Patients With Cancer and Nonviral Pneumonia: A Target Trial Emulation

Abstract Purpose Adjunctive corticosteroids reduce mortality in selected patients with severe community-acquired pneumonia, but their benefit in critically ill patients with cancer remains uncertain because this population is underrepresented in randomized trials. We emulated a target trial to evaluate early corticosteroid initiation and hospital mortality in critically ill adults with malignancy and nonviral pneumonia. Methods We emulated a target trial using MIMIC-IV among adults with active malignancy and nonviral pneumonia who remained alive and hospitalized 48 hours after ICU admission. Treatment strategies were corticosteroid initiation within 48 hours or no corticosteroids during this period. The primary outcome was hospital mortality. Propensity score-based IPTW was used for confounding adjustment, with prespecified sensitivity analyses using a 24-hour exposure window and propensity score matching. Results The landmark cohort included 2,227 patients, of whom 531 (23.8%) received early corticosteroids. The primary IPTW analysis included 2,160 complete cases. IPTW achieved adequate balance across all covariates in the primary propensity score model. Early corticosteroid initiation was not associated with hospital mortality (OR, 1.01; 95% CI, 0.80–1.27; P = 0.925). Findings were consistent after multivariable adjustment, propensity score matching, and alternative exposure definitions. Early corticosteroid initiation was associated with shorter hospital but not ICU length of stay or invasive mechanical ventilation duration. Conclusion Among critically ill adults with active malignancy and nonviral pneumonia, early corticosteroid initiation was not associated with hospital mortality. These findings do not support extrapolating evidence favoring adjunctive corticosteroids in selected patients with severe community-acquired pneumonia to critically ill patients with cancer.