Testing the generalizability of national reimbursement rates with respect to local setting: the costs of abdominal aortic aneurysm surgery in Denmark

Søren Løvstad Christensen¹, Mette Kjoelby^1,2, Lars Ehlers^3
1Health Technology Assessment and Health Services Research, Centre for Public Health, Central Denmark Region, Denmark; ²School of Public Health, Aarhus University, Denmark; ³Health Economics and Management, Aalborg University, Denmark

Objective: The purpose of this study is to investigate if the Danish national diagnosis-related group (DRG) tariffs for surgery for abdominal aortic aneurysm (AAA) were good estimates of the actual costs in two local hospitals in the Central Region of Denmark.
Methods: We collected clinical data for 178 AAA patients operated at Skejby Hospital and Viborg Hospital in the period 2005–2006 from the Danish National Vascular Registry and economic data from the administrative systems in the hospitals. We used bootstrap methods to calculate 95% confidence intervals (CIs) for the mean costs of surgery for ruptured AAA, nonruptured AAA and AAA where the patient died within 30 days by applying a cost-trimming rule that the Danish National Board of Health uses in calculating national DRG tariffs.
Results: The national DRG tariff lies within the calculated Danish Krone (DKK) CIs (CI ruptured AAA, 98,178–195,327 [€13,196–€26,254]; CI nonruptured AAA, 79,039–98,178 [€10,624–€13,196]; CI dead, 42,023–111,685 [€5,648–€15,011]), and thus national DRG tariffs could be a good estimate for the actual costs in the local hospitals.
Conclusion: The bootstrap method is useful for testing the generalizability of national DRG tariffs as estimates of local surgical costs.

Keywords: bootstrap method, costs, DRG, abdominal aortic aneurysm