Who is more likely to receive up-to-date lung cancer screening? Identifying key barriers using principal component analysis and SHAP modeling: a weighted cross-sectional analysis of the 2024 BRFSS.

Background: Up-to-date lung cancer screening (UTD-LCS) uptake remains low. This cross-sectional study examines how social determinants and physical or mental well-being are associated with UTD-LCS using multiple analytical methods with appropriate survey weighting. Methods: We analyzed 6,234 eligible adults aged 50-79 from the 2024 Behavioral Risk Factor Surveillance System (BRFSS), applying complex survey weights throughout all analyses. Principal Component Analysis (PCA) was used to combine 14 social determinants and health indicators into latent dimensions. Partitioning Around Medoids (PAM) clustering stratified the population into distinct subgroups based on the optimal number of clusters determined by silhouette coefficients, and SHapley Additive exPlanations (SHAP) were employed to visualize the specific predictors of screening uptake within each cluster. A sensitivity analysis was conducted excluding adults aged 78-79 to assess the potential implications of the Medicare coverage gap on screening behaviors. Results: The weighted UTD-LCS uptake was 20.0% (SE = 1.1%). PCA identified four components explaining 56.0% of the variance: Socioeconomic Resources, Physical Health, Psychosocial Health, and Employment & Neighborhood. In the fully adjusted weighted logistic regression, only Socioeconomic Resources was independently associated with screening (OR = 0.822, 95% CI: 0.713-0.948, Conclusion: Socioeconomic deprivation is the primary barrier to UTD-LCS. While poor physical health prompts screening, the Medicare coverage gap may potentially hinder this pathway.