A comparison of actual registered costs and costs derived from diagnosis-related groups (DRGs) for patients undergoing heart transplantation, lung transplantation, and thoracotomy for other lung diseases

The Norwegian health care system, like other health care systems in the world, is in the midst of a changing financial environment for hospital reimbursement for patient care. Since 1997 the Norwegian government has introduced a new financing model of block grant and activity-based financing. In this model, diagnosis-related groups (DRGs) play an important role in hospital financing. The initial motive for developing the DRGs was to improve hospital productivity and efficiency and to develop a tool to control increasing hospital costs better. We raised the question as to whether the DRG system in fact covers actual costs in patient groups undergoing heart transplantation (n = 12), lung transplantation (n = 4), and thoracotomy for other diseases (n = 10). A new prospective cost model was developed to measure actual costs related to individual patients. The patients were closely observed and the related data collected during the hospital stay. Each patient's hospital stay was divided into four different categories of resource requirements, defined as heavy intensive care, light intensive care, intermediate care, and ordinary care. In addition, the number of staff involved and the duration of surgery and procedures were recorded, as were medicine costs and material costs. Based on these data, the actual costs for each patient were calculated. These were then compared with the respective DRG reimbursement (100% coverage) for the corresponding group. We found that the median cost for heart transplantation was US$ 50,590 (1 US$ = 7.5 NOK based on the exchange rate at the time of the study), while the respective DRG reimbursement was US$ 65,662. For lung transplantation, the respective figures were US$ 46,668 vs US$ 65,662, and for thoracotomy, US$ 24,307 vs US$ 11,004. We found that our method was applicable to a hospital setting. DRG coverage for heart and lung transplantation seems to overestimate the actual costs. For the thoracotomy procedure, the DRG coverage did not cover the actual costs.