Socioeconomic Deprivation, Primary Care Physician Workload and Colorectal Cancer Screening Adherence Across Italian...

Background: Socioeconomic deprivation is a well-established determinant of participation in colorectal cancer (CRC) screening. However, less is known about the geographic clustering of screening adherence and whether spatial inequalities mirror regional patterns of socioeconomic disadvantage. This study investigated the association between socioeconomic deprivation and adherence to CRC screening across Italian regions and explored the presence of spatial autocorrelation using geographic analytical methods. Methods: We conducted a nationwide ecological cross-sectional study including 21 Italian regional units. Pearson correlation analysis was performed to explore associations between colorectal cancer (CRC) screening adherence, primary care physician (PCP) workload and socioeconomic deprivation. Multivariable linear regression was used after assessment of multicollinearity using variance inflation factors (VIFs). Sensitivity analyses included alternative deprivation indicators and leave-one-region-out analyses. Spatial dependence was evaluated using Global Moran's I and Local Indicators of Spatial Association (LISA). Results: CRC screening adherence showed substantial geographic variability across Italy, with higher participation in northern regions and lower participation in southern areas. Screening adherence was inversely associated with socioeconomic deprivation. Sensitivity analyses confirmed the robustness of the association across alternative deprivation measures and sequential exclusion of each regional unit. Spatial analysis demonstrated significant positive spatial autocorrelation (Moran's I = 0.275; p = 0.039), indicating that neighbouring regions tended to exhibit similar screening behaviours. LISA analysis identified significant High-High clusters in northern Italy, Low-Low clusters in southern and insular regions, and isolated spatial outliers, highlighting persistent territorial inequalities in preventive healthcare utilisation. Conclusions: Regional disparities in CRC screening participation were associated with socioeconomic deprivation and modest but significant spatial clustering. These findings provide a regional-level description of inequalities in screening participation and may help inform future public health strategies aimed at reducing disparities in organised colorectal cancer screening.