Abstract
OBJECTIVE: Lung cancer remains the leading cause of cancer death in the United States. Mobile screening units have reduced access barriers. To assess lung cancer screening spatial access, we utilized a two-step floating catchment analysis (2SFCA) and an enhanced two-step floating catchment analysis (E2SFCA) to identify areas for mobile screening deployment. METHODS: A spatial analysis was conducted using 2019-2023 census block group population data (ages 50-80) and a validated list of 165 lung cancer screening facilities in Oklahoma collected between December 2024 - May 2025, United States. Block groups were categorized into four spatial access groups. Analyses incorporated rural-urban continuum area codes. The 2SFCA used 30-min drive-time catchments, while the E2SFCA applied gravity-weighted 10-, 20-, and 30-min catchments. RESULTS: Across both methods, 41 % of eligible Oklahomans resided in low or no spatial access areas, covering over 60 % of the state's land. Small rural areas had the highest proportion of residents (up to 67 %) with limited or no spatial access. Urban areas showed better spatial access, but up to 19 % of eligible residents still lacked 30-min access. CONCLUSIONS: Large sections of Oklahoma, particularly rural, lack spatial access to lung cancer screening. The 2SFCA and E2SFCA methods effectively identified underserved regions.