[Self-critical, multicenter analysis of treatment and coding quality using the example of nephroureterectomy on the basis of billing data].

Background: Urothelial carcinomas of the upper urinary tract (UTUC) are rare, accounting for approximately 5-10% of all urothelial carcinomas. In contrast to urothelial carcinomas of the bladder, UTUCs are often invasive at the time of diagnosis. Radical nephroureterectomy (RNU) is the gold standard for treatment, with minimally invasive procedures gaining increasing importance. Aim of this study was to examine the development of RNU in terms of case numbers, surgical methods, treatment quality, and guideline adherence.

Materials and methods: This study is based on a retrospective analysis of German Diagnosis-Related Groups (G-DRG) billing data from 87 Helios hospitals in Germany for the period 2016-2022. Patients with a primary diagnosis of UTUC who had undergone RNU were included. Surgical procedures were classified as open surgery or minimally invasive (laparoscopic or robot-assisted). Various parameters such as length of hospital stay (LOS), complications and postoperative interventions were analyzed. A post hoc survey of the clinics served to validate billing data.

Results: A total of 594 patients underwent RNU. The proportion of robot-assisted RNU steadily increased, while open procedures decreased. Minimally invasive procedures resulted in shorter hospital stays (9.9 days vs. 12.3 days; p < 0.001), fewer complications such as anemia due to bleeding (12% vs. 26%), and a decreasing need for intensive care (57% vs. 71%; p < 0.001). Bladder cuff resection was less frequently performed in minimally invasive RNU (6.6% vs. 46%; p < 0.001). However, intravesical instillation of chemotherapeutic agents was only performed in a small proportion of patients regardless of surgical method (10% vs. 6.9%; p = 0.116), although the post hoc survey revealed a coding bias and showed a cuff resection rate of 92% and an instillation rate of 52%.

Conclusion: Robotic surgeries demonstrated significant advantages with regard to hospital stay and complications. However, insufficient guideline adherence was noted regarding postoperative instillation, highlighting points for improvement. The analysis shows a clear discrepancy (real-world evidence gap) between coded DRG data and actual clinical care. This disparity influences key structural and service decisions in the German healthcare system and must be urgently taken into account when interpreting administrative datasets.