Background: Social and geographical health inequalities remain a significant barrier to breast cancer screening (BCS). Mobile mammography units (MMUs), deployed according to the principle of proportionate universalism, could help mitigate these disparities by improving accessibility for underserved populations.
Objectives: To evaluate the contribution of MMUs to increasing screening participation through a prospective cluster-randomised controlled trial conducted in France. Additionally, to assess the cost-effectiveness of integrating MMUs into the French organised BCS program.
Methods: This interventional study was conducted among the general population in four departments of the Normandy region. Areas located >15 min from a radiology centre (RC) were grouped into clusters and randomly assigned (1:1) to either an intervention or control arm. The study included 320 clusters encompassing 87,449 women (aged 50–74): 49,067 in the control arm and 38,382 in the intervention arm. A cost-effectiveness analysis was conducted from the healthcare payer perspective, comparing the standard strategy (attendance at an RC only) with an alternative strategy offering the choice between an RC or an MMU, based on participant preference. The primary outcome was the BCS participation rate, compared using a cluster-adjusted proportion test. Economic outcomes were expressed as the incremental cost-effectiveness ratio.
Results: In the intervention arm, 22,964 women were screened out of the 38,382 invited, yielding a participation rate of 59.8% vs 51.1% in the control areas (25,099/49,067). The MMU intervention was associated with a statistically significant increase in participation of 8.7% (p<0.0001) compared with the control arm. In the intervention arm, women screened in the MMU tended to be younger and more deprived than those who opted for a radiology centre. In the intervention arm, the mean cost per woman invited was €69.18 compared to €43.75 in the control arm, representing an incremental cost of €25.43. The incremental cost per additional woman screened was €292.95.
Conclusions: Integrating MMUs into the organised breast cancer screening programme significantly increased participation among women living furthest from radiology centres and can reduce socio-geographical inequalities. With an ICER well below the suggested threshold of 1x GDP per capita (€37,567), the strategy combining UMM and CR is cost-effective. Ensuring the availability of qualified professionals to staff MMUs is essential for maintaining service quality