Pulmonary Versus Nonpulmonary Mucormycosis: A Comparative Analysis of Clinical Characteristics and Inpatient Outcomes Using the National Inpatient Sample

Background: Comparative data on pulmonary and nonpulmonary mucormycosis are limited. Methods: We analyzed adult hospitalizations in the United States Healthcare Cost and Utilization Project National Inpatient Sample from 2018 through 2021. Pulmonary involvement was identified by ICD-10-CM code B46.0. Survey-weighted models adjusted for age, sex, diabetes, hematologic malignancy, and hematopoietic stem cell transplantation; mortality was examined separately with additional illness-severity adjustment. Results: Among 1120 sampled adult hospitalizations, representing approximately 5600 weighted hospitalizations, 308 (27.5%) had pulmonary involvement. Pulmonary cases more often had hematologic malignancy, transplantation, and extreme illness severity while having diabetes less often. Pulmonary involvement was associated with acute respiratory failure defined by J96.0 codes (adjusted odds ratio [aOR], 1.54; 95% confidence interval [CI], 1.14–2.07) and invasive mechanical ventilation (aOR, 1.49; 95% CI, 1.08–2.06). In-hospital mortality did not differ significantly in the crude comparison (24.03% versus 20.57%; p = 0.1916), baseline-adjusted model (aOR, 1.11; 95% CI, 0.81–1.53), or model additionally adjusted for illness severity (aOR, 0.96; 95% CI, 0.69–1.34). Respiratory associations persisted after excluding pulmonary cases with concurrent nonpulmonary mucormycosis coding. Conclusions: Pulmonary involvement was associated with greater respiratory morbidity among US hospitalizations with coded mucormycosis. No statistically significant mortality association was detected; these findings do not establish equivalence or a causal effect of infection site.