Disparities related to myelofibrosis: A retrospective analysis of US mortality data

Abstract

Abstract Background Myelofibrosis (MF) is a rare clonal myeloproliferative neoplasm characterized by progressive bone marrow fibrosis, cytopenias, and reduced survival. Although therapeutic advances such as JAK inhibitors have become available over the past decade, the population-level burden and sociodemographic disparities in MF-related mortality remain poorly characterized. This study evaluates nationwide trends and disparities in MF-related mortality across demographic and geographic subgroups in the United States over 22 years. Method We conducted a retrospective population-based analysis using the CDC WONDER Underlying Cause of Death database to identify all deaths from 1999 to 2020 in which myelofibrosis (ICD-10 code D47.1) was listed as an underlying cause. Age-adjusted mortality rates (AAMRs) per 100,000 population were calculated using the 2000 United States standard population. Mortality was stratified by sex, race, ten-year age group, urbanization, place of death, and state of residence. Results A total of 28,668 MF-related deaths occurred in the United States from 1999 to 2020, with an overall AAMR of 0.390 per 100,000 (95% CI: 0.386–0.395). Males had a significantly higher AAMR than females (0.524 vs. 0.296), accounting for 55.0% of all deaths. AAMRs were highest among White individuals (0.410), followed by Black (0.284), Asian/Pacific Islander (0.207), Hispanic (0.195), and American Indian/Alaska Native (0.142). Adults aged ≥65 accounted for 88.2% of all MF-related deaths, with the highest crude mortality rate observed in those aged ≥85 years (6.95 per 100,000). Rural populations experienced disproportionately higher mortality. AAMRs were highest in small metropolitan (0.427), micropolitan (0.427), and non-core rural areas (0.415), compared to large central metropolitan areas (0.350). Most deaths occurred in inpatient medical facilities (39.1%), followed by home (31.4%) and nursing homes or long-term care facilities (17.7%). The highest state-level rates were observed in Wisconsin (0.544), Nebraska (0.526), and Montana (0.540), while the lowest were in Mississippi (0.261), Arizona (0.288), and Nevada (0.317). Conclusion From 1999 to 2020, older males and those in rural populations consistently experienced higher myelofibrosis-related mortality. The predominance of deaths among individuals over age 65 underscores the prognostic weight of age, a core variable in established scoring systems such as the International Prognostic Scoring System (IPSS). These findings highlight the ongoing need to ensure timely diagnosis, equitable access to treatment, and individualized care strategies, including palliative care, particularly for older adults and medically underserved populations.