Outcomes of pneumococcal disease in patients with B-cell malignancies: A retrospective cohort study.

e23110 Background: Streptococcus pneumoniae disproportionately affects adults with B-cell hematologic malignancies due to profound humoral immune dysfunction and B-cell–depleting therapies. Although ACIP recommends pneumococcal conjugate vaccination for all immunocompromised adults, guidance does not distinguish B-cell malignancies from other hematologic cancers. National data defining severe inpatient outcomes in this high-risk subgroup are limited. We evaluated outcomes of pneumococcal disease hospitalizations among adults with B-cell hematologic malignancies. Methods: We conducted a retrospective study of hospitalizations with a principal diagnosis of pneumococcal disease using in the HCUP all-payer database (2018–2021). The primary exposure was B-cell hematologic malignancy. Primary outcome was in-hospital mortality; key secondary outcomes were invasive mechanical ventilation (IMV), length of stay (LOS), and total hospital charges. Weighted multivariable logistic regression (odds ratios OR, 95% confidence intervals CI) and linear regression (beta B) adjusted for demographics, payer, socioeconomic status, comorbidity burden, sepsis severity, and hospital factors were used to estimate effects. Results: Among an estimated 186, 860 pneumococcal hospitalizations, B-cell hematologic malignancy was independently associated with higher odds of IMV (OR 1. 87, 95% CI 1. 73–2. 02; p < 0. 001) but not increased in-hospital mortality (OR 0. 97, 95% CI 0. 86–1. 10; p = 0. 629). B-cell malignancy was associated with longer LOS (B = 0. 69 days; p < 0. 001) and a marginal increase in cost (B = 4, 729; p = 0. 051). Acute illness severity dominated outcomes: ventilator use strongly predicted mortality (OR 8. 18, 95% CI 7. 80–8. 57; p < 0. 001), and sepsis/severe sepsis were major drivers of IMV and death (all p < 0. 001). In secondary analyses, results were directionally consistent when expanding exposure to all hematologic malignancies (IMV OR 1. 87; mortality OR 0. 95). Conclusions: Adults with B-cell hematologic malignancies hospitalized for pneumococcal disease experienced significantly higher risk of invasive mechanical ventilation and longer hospital stays, without increased adjusted in-hospital mortality. These findings support prioritization and systematic delivery of pneumococcal conjugate vaccination strategies in B-cell malignancy populations to reduce severe respiratory morbidity and healthcare utilization. Adjusted association of B-Cell hematologic malignancy with inpatient outcomes. Outcome Adjusted Effect Estimate 95% CI p-value In-hospital mortality OR 0. 97 0. 86–1. 10 0. 629 Invasive mechanical ventilation OR 1. 87 1. 73–2. 02 <0. 001 Length of stay (days) B = +0. 69 0. 43–0. 96 <0. 001 Total hospital charges (USD) B = +4, 729 −29 to 9, 487 0. 051