Does German Hospital Financing Lead to Distorted Incentives in the Billing of Intensive Care Ventilation Therapy?

Introduction: In the German statutory health insurance system, hospitals are reimbursed according to the services provided. One important variable in the calculation of reimbursements is the hours of mechanical ventilation provided in the course of intensive care treatment. The amount of compensation is directly proportional to the number of hours of ventilation and increases when certain thresholds are reached (96, 250, 500, and 1000 h of ventilation). From an economic point of view, this is an incentive structure toward prolonged ventilation regardless of medical implications in order to increase the amount of compensation received. Methods: In this study, the frequency of ventilation hours at and shortly after the critical thresholds were examined for anomalies in all cases billed to health insurers from 2009 to 2019. It was examined whether a significant accumulation of ventilation hours could be observed at and shortly after a threshold was reached. Results: Descriptive analysis of the data showed that the mean values of ventilation hours around the critical thresholds (96, 250, 500, and 1000) are higher than before the critical thresholds for most years. Accordingly, the rates of change at and shortly after critical thresholds are also higher than otherwise. Statistical analysis was used to examine the differences in rates of change between critical and non-critical thresholds. It was shown that the median and mean rates of change are significantly higher for critical thresholds than for non-critical thresholds. Therefore, the null hypothesis that there is no difference in the rates of change between the critical and non-critical thresholds can be rejected. Application of the bootstrap test confirmed the robustness of these results. Conclusions: The results at the descriptive, exploratory and inductive levels showed a clear trend toward increased ventilation hour frequency at critical thresholds. The results of this study may help to develop strategies to lower the frequency of ventilation hours and thereby reduce overall healthcare costs.