Abstract
BACKGROUND: The number of immunocompromised patients with community-acquired pneumonia (CAP) admitted to intensive care unit (ICU) is rising, accompanied by high mortality. Although glucocorticoid (GC) therapy is recommended for severe CAP by Society of Critical Care Medicine (SCCM) in 2024, its efficacy in immunocompromised patients remains uncertain. This study aimed to evaluate the impact of GC therapy on mortality in immunocompromised patients with CAP in the ICU. METHODS: A retrospective cohort study was conducted using the MIMIC-IV 3.1 database. Primary outcomes was twenty-eight days (28-d) mortality. Secondary outcomes included six months (6-m) and twelve months (12-m) mortality, in-hospital mortality, ICU mortality, hospital and ICU length of stay, and 28-d ventilator-free days. Propensity score matching (PSM) was applied to minimize selection bias. Cox proportional hazards models were used to assess the association between GC therapy and mortality, also including analyses of timing, duration, and average daily dose of GC administration. Sensitivity analysis was performed using E-values. RESULTS: A total of 1770 patients were included, with 593 receiving antibiotics plus GC therapy. After PSM, 521 patients were included in both the GC and non-GC treatment groups. GC therapy was associated with increased 28-d mortality (GC vs non-GC, after PSM: 29% vs 23%, HR = 1.373, p < 0.05). Secondary outcome, GC therapy was associated with increased 6-m and 12-m mortality (GC vs non-GC, after PSM: 6-m, 47% vs 43%; 12-m, 56% vs 51%, HR = 1.215; p < 0.05). Six different Cox models confirmed GC therapy was associated with increased 28-d mortality (HR = 1.337-1.374, p < 0.05). Initiating GC therapy > 48 hours after ICU admission, treatment duration > 7 days, and low-dose GC (≤0.5 mg/kg/d) were also linked to higher 28-d mortality (p < 0.05). E-value analysis indicated the results were relatively robust. CONCLUSION: Among immunocompromised CAP patients in the ICU, GC therapy may increase 28-d，6-m and 12-m mortality, an association potentially attributable to its late initiation, prolonged duration, and insufficient dosage. Further research is needed to define the optimal GC treatment regimen for this population.