Trends in chronic lymphocytic leukemia mortality among patients with pneumonia in the United States (1999–2024): A CDC wonder database analysis

Abstract INTRODUCTION: Chronic lymphocytic leukemia (CLL) is a common hematologic malignancy among older adults, with pneumonia representing a frequent and life-threatening complication due to immune dysregulation. Despite advances in care, the mortality burden of coexisting CLL and pneumonia remains inadequately characterized. This study assesses national mortality trends in CLL patients with pneumonia from 1999 to 2024. METHODS: We used the CDC Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) database to analyze death certificate data from 1999 to 2024 for adults aged ≥65 years, where CLL was listed as the underlying cause of death and pneumonia as a contributing cause. Age-adjusted mortality rates (AAMRs) were calculated per 1000,000 population. Trends were assessed using Joinpoint regression to determine annual percent changes (APCs). RESULTS: A total of 13,951 deaths were recorded with CLL as the primary and pneumonia as a contributing cause. AAMRs decreased markedly by 68%, from 21.0 in 1999 to 6.7 in 2024. A significant decline occurred from 1999 to 2014 (APC: -4.18), followed by a steeper decline through 2021 (APC: -8.02), then stabilizing thereafter. Males had over twice the AAMR (20.4) compared to females (8.3). Non-Hispanic Whites (13.8) had the highest AAMRs. Rates were elevated in non-metropolitan (15.9) versus metropolitan (13.2) areas, with the Midwest showing the highest regional AAMR (14.7). CONCLUSION: Despite substantial improvements in CLL-pneumonia mortality over the past two decades, disparities by sex, race, and geography persist. Tailored public health efforts are needed to reduce mortality in vulnerable populations. Keywords: Chronic Lymphocytic Leukemia; Pneumonia; Age-Adjusted Mortality Rates; CDC WONDER; Hematologic Cancers; Rural Health Disparities; Epidemiologic Trends.