County-level palliative care physician density and socioeconomic determinants of place of cancer death in the United States, 2021-2023.

12032 Background: Palliative care, a specialized approach focused on care for individuals with serious illness including cancer, has been shown to improve end-of-life outcomes, including higher rates of death in preferred settings. However, access to palliative care remains inequitable due to significant geographic disparities in workforce distribution. This study examines the association between county-level palliative care physician density and place of death among US decedents died from cancer. Methods: We conducted a retrospective cohort study using CDC WONDER multiple cause of death data (2021-2023) linked with palliative care physician supply data from the American Medical Association (AMA) Physician Masterfile. The primary exposure was county-level palliative care physician density, categorized as zero, below-median, or above-median (among non-zero counties). The primary outcome was the county-level percentage of cancer deaths (ICD: C00-C97) occurring in non-hospital settings (home, hospice, long-term care, or nursing home). Covariates include county sociodemographic characteristics (race/ethnicity, median income, region, metropolitan status) and hospice facility availability. Multivariable regression models estimated associations between physician density and place of death, adjusting for other covariates. All models incorporated county population weighting and state-level clustering. Results: Most U.S. counties (n = 2056, 66.27%) had no palliative care physicians in 2020. Counties with palliative care physicians showed higher median household incomes, more hospice facilities and metropolitan status, and were concentrated in the Northeast and West (all p < 0.001). The average percentage of non-hospital facility deaths across all counties was 56.6% (SD = 7.1) for all causes, 60.5% (SD = 8.1) for heart disease, and 70.7% (SD = 8.0) for malignant neoplasms. Multivariable regression models revealed a dose-response relationship: counties with non-zero below median and above-median palliative care physician density showed 0.9 percentage points (ppts, p < 0.05) and 1.1 ppts (p < 0.05) higher proportions of cancer death at non-hospital facility-based facilities than counties without palliative care physicians. In addition, Metropolitan and Micropolitan counties had 2.5 ppts (p < 0.001) and 2.1 ppts (p < 0.001) higher proportions of cancer death at non-hospital facility-based facilities than non-metropolitan counties respectively. Conclusions: Higher county-level palliative care physician density is associated with increased non-hospital facility-based deaths for cancer, demonstrating a clear dose-response relationship. These findings suggest that ensuring access to palliative care, through workforce expansion or care delivery model innovation may facilitate end-of-life care planning aligned with patient preferences.