Background: Cream skimming can be defined as the selective treatment of patients that demand little resources while providing high economic refunds. We test whether cream skimming occurs after the introduction of DRG-based activity-based financing (ABF) in Norway in 1997 and if the problem further increases after the 2002
organizational reform where hospitals were turned into trusts. The DRG-system offers the same economic reimbursement for patients classified within day-surgical DRGs irrespective of whether the patient receives same-day treatment or in-patient care over several days. This both gives a potential for cream skimming and allow us to investigate cream skimming within the actual diagnoses.
Method: Patient data from the period 1999-2005 is analyzed. Waiting time, as an indicator of patient selection, is analyzed as a function of severity within each diagnosis, controlling for age and gender of the patient, as well as institutional and time-dependent variables.
Results: The analysis gives some evidence of cream skimming in the period of ABF, in particular within the lighter orthopaedic diagnosis. However, cream skimming does not increase after the 2002 organizational reform but is stable, or for some DRGs even reduced. Conclusion: The study indicates that cream skimming may occur if the reimbursement system is not particularly sophisticated, but also that political signalling can reduce the problem.