It would be preferable to increase the add-on payments for difficult cases to progressively eliminate these disparities, as DRG payments could allow only a partial reduction of the heterogeneity of patients across establishments (Milcent, 2016a; Veran, 2016). They may also give incentives to optimise the reporting of activity and overstate the difficulties of each patient. In France, DRG groups capture less than half of patients’ heterogeneity (Milcent, 2016b), and up-coding (i.e. deliberately overstating the case-mix) appears significant, as in the United States (Milcent, 2016a and 2016b; Dafny, 2005). Moreover, as in primary care, the payment structure provides little incentive for prevention and co-ordination between care providers.