Breast cancer screening programme participation and socioeconomic deprivation in France.

The objective was to quantify the relationship between deprivation and national breast cancer screening programme (NBCSP) participation at an ecological level in mainland France. Data from 4,805,390 women-living in 36,209 municipalities within 95 departments-participating in the 2013-2014 NBCSP were analysed using the French Deprivation Index (FDep). FDep population quintiles by municipality were computed to describe NBCSP participation according to deprivation. To better examine the relationship between continuous value of deprivation index and participation rates at the municipality level, we built a generalized linear mixed model. Geographical variations in participation rates were marked. The national standardized participation rate was higher in the intermediate quintiles (55%), 45% for the least deprived one and 52% for the most deprived one. Using our model, we also obtained an inverted U-curve for the relationship between NBCSP participation and municipality deprivation: participation was lower for both the least and most deprived municipalities. This relationship was also observed for each of the two subpopulations-urban municipalities and rural ones-considered separately. Introducing the FDep in the model reduced slightly the unexplained variations in participation rates between departments and between municipalities (with a proportional change in variance of 14% and 12% respectively). We highlight major disparities in departmental participation rates and FDep/participation profiles. However, deprivation appears to have only little influence on geographical variation in participation rates. There is a need to further understand the factors affecting geographical variation in participation rates, in particular the use of opportunistic screening.