Socio-Territorial Inequities in the French National Breast Cancer Screening Programme-A Cross-Sectional Multilevel Study.

Background: France implemented in 2004 the French National Breast Cancer Screening Programme (FNBCSP). Despite national recommendations, this programme coexists with non-negligible opportunistic screening practices.

Aim: Analyse socio-territorial inequities in the 2013-2014 FNBCSP campaign in a large sample of the eligible population.

Method: Analyses were performed using three-level hierarchical generalized linear model. Level one was a 10% random sample of the eligible population in each ( = 397,598). For each woman, age and travel time to the nearest accredited radiology centre were computed. These observations were nested within 22,250 residential areas called "Îlots Regroupés pour l'Information Statistique" (IRIS), for which the European Deprivation Index (EDI) is defined. IRIS were nested within 41 , for which opportunistic screening rates and gross domestic product based on purchasing power parity were available, deprivation and the number of radiology centres for 100,000 eligible women were computed.

Results: Organized screening uptake increased with age (OR = 1.05 [1.04-1.06]) and decreased with travel time (OR = 0.94 [0.93-0.95]) and EDI (OR = 0.84 [0.83-0.85]). Between , organized screening uptake decreased with opportunistic screening rate (OR = 0.84 [0.79-0.87]) and deprivation (OR = 0.91 [0.88-0.96]). Association between EDI and organized screening uptake was weaker as opportunistic screening rates and as deprivation increased. Heterogeneity in FNBCSP participation decreased between IRIS by 36% and between by 82%.

Conclusion: FNBCSP does not erase socio-territorial inequities. The population the most at risk of dying from breast cancer is thus the less participating. More efforts are needed to improve equity.