The impact of smoking prevalence on the spatial relationship between lung cancer screening access and mortality across U.S. counties

<title>Abstract</title> <p>Background Lung cancer is the leading cause of cancer death in the United States, yet uptake of low-dose computed tomography screening remains low. Geographic access to screening facilities is a recognized barrier, but the spatial relationship between screening-center distribution and lung cancer mortality burden has not been formally quantified. Methods We conducted a cross-sectional spatial analysis linking 2024 American College of Radiology Designated Lung Cancer Screening Centers with 2018–2022 age-adjusted lung cancer mortality and 2023 CDC PLACES smoking prevalence across 2701 U.S. counties. We used bivariate mapping to identify facility and mortality clusters, and a multivariable Spatial Error Model (SEM) to evaluate the independent association between population-standardized facility density and mortality, adjusting for spatial autocorrelation, smoking prevalence, and rurality. Results Bivariate mapping identified Low Facility–High Mortality clusters concentrated in the Southeast and Appalachia. However, spatial regression revealed this ecological pattern was primarily driven by geographic disparities in smoking prevalence (Estimate = 2.04, p &lt; 0.001) and rurality. After adjustment, population-standardized screening facility density was not a statistically significant independent predictor of lung cancer mortality (Estimate = 0.28, p = 0.109). Conclusions The spatial mismatch between screening facilities and lung cancer mortality is heavily confounded by regional smoking prevalence. Needs-based screening expansion must be integrated with comprehensive smoking cessation programs to effectively reduce geographic mortality disparities.</p>