Effect of the Implementation of the French Hospital Regionalization Policy on Patient Mobility.

A new law was voted in France in 2016 to increase cooperation between public sector hospitals. Hospitals were encouraged to work under the leadership of local referral centers and to share their support functions (e.g., information systems) with newly created hospital groups, called "Regional Hospital Groups." The law made it compulsory for each public sector hospital to become affiliated with one of 136 newly created hospital groups. The policy's aim was to ensure that all patients were sent to the hospital best qualified to treat their unique condition, among the hospitals available at the regional level. Therefore, we aimed to assess whether this regionalization policy was associated with changes in observed patterns of patient mobility between hospitals. This nationwide observational study followed an interrupted time series design. For each stay occurring from 2014 to 2019, we ascertained whether or not the stay was followed by mobility toward another hospital within 90 days, and whether or not the receiving hospital was part of the same Regional Hospital Group as the sender hospital. The proportion of mobility directed toward the same regional hospital group increased from 22.9% in 2014 (95% CI 22.7-23.1) to 24.6% in 2019 (95% CI 24.4-24.8). However, the absence of discontinuity during the policy change year was consistent with the hypothesis of a preexisting trend toward regionalization. Therefore, the policy did not achieve major changes in patterns of mobility between hospitals. Other objectives of the reform, including long-term consequences on the healthcare offer, remain to be assessed.