Many OECD countries have introduced systems of payment per activity to finance their health establishments. In 2004 France adopted the “activity-based pricing” reform (T2A) to encourage these establishments to adopt greater efficiency. The implementation of this reform has so far primarily incorporated economic necessities as a first concern. However for the regulator, it is important to monitor the effects of this reform in terms of quality of care. A measurement of the quality of patient care can be seen through the readmission rate after thirty days. The purpose of this study is to focus on readmission both during the period preceding the T2A and during the period following its implementation. The study period is from 2002 to 2012. Using data from the hospital information system program (PMSI), for each hospital stay for surgery, readmission thirty days after the release is determined using PMSI chain-linking, provided that these readmissions are neither treatment sessions nor for neonatology. The probability of readmission is modelled using multiple logistic regression which includes the following cofactors: year, age, gender, mode of admission, length of stay, morbidity, legal status of the establishment and the terms of interactions. The results highlight an increased risk of readmission observed overall, but which is explained by a change in the population structure (aging) as well as by changes in care. This increase in readmissions cannot be explained by the implementation of the T2A.