German Registry Data Do not Adequately Reflect Reality

Correspondence regarding the article Allocation Rules and Age-Dependent Waiting Times for Kidney Transplantation by Dr. med. Benedikt Kolbrink, Dr. med. Nassim Kakavand, Jakob C. Voran, Prof. Dr. rer. nat. Helena U. Zacharias, Dr. med. Axel Rahmel, Dr. Serge Vogelaar, Prof. Dr. rer. nat. Silke Schicktanz, Prof. Dr. med. Felix Braun, Prof. Dr. med. Roland Schmitt, Dr. med. Friedrich A. von Samson-Himmelstjerna, and PD Dr. med. Kevin Schulte in issue 17/2024

The authors address an important issue in transplantation medicine: the age group-dependent waiting times for kidney transplantation (NTx) (1). On the basis of data from the German Transplant Registry (TxR), it is shown that in the patient group up to the age of 18, the waiting time is 1.7 years, up to the age 65 it is 7.0 years and from the age of 65 onwards only 3.8 years (1). The consequence of this is different survival chances on the waiting list and after transplantation, which are discussed but were not the subject of the investigation.

The analysis is apparently based on the “elements transplantation” of old and new data from the TxR, covering 32 255 kidney transplants. After excluding living donations and further data adjustments, the analysis included 19,664 KTx. Using the same criteria, we arrived at a total of 18 359 patients. The new TxR data only includes 46% of the patients transplanted according to the Eurotransplant statistics (2), and allocations in the Acceptable Mismatch Program amounted to 4.8% (2014–2018), while the authors report 2.1%. These discrepancies reflect the limitations of the registry (3, 4). Further studies, such as simulation models to equalize waiting time differences among adults, require a complete and precise dataset for the entire process from listing to follow-up, excluding “garbage in, garbage out” effects. In the TxR, deficient data acquisition, incompleteness, inaccuracies, and arbitrary evaluations due to redundancies lead to unscientific results, making analyses with consequences for survival-related decisions impossible.

The authors deserve credit for presenting differences in waiting times that are difficult to justify. Unfortunately, the data of the German Transplant Registry is unusable for further conclusions.

DOI: 10.3238/arztebl.m2024.0220

Prof. em. Dr. med. Gerd Otto
Ehem. Abteilung für Hepatobiliäre und Transplantationschirurgie
Universitätsmedizin Mainz, Mainz Germany

Prof. Dr. med. Christoph Bara
Klinik für Herz-, Thorax- und Gefäßchirurgie, Herzzentrum
Universitätsmedizin Göttingen, Göttingen, Germany

Prof. Dr. med. Jens Gottlieb
Klinik für Pneumologie und Infektiologie
Medizinische Hochschule Hannover, Hannover, Germany

Prof. Dr. med. Klemenz Budde
Medizinische Klinik mit Schwerpunkt Nephrologie und
Internistische Intensivmedizin
Charité Berlin, Berlin, Germany

Conflict of interest

The authors declare no conflict of interest.

References

1. Kolbrink B, Kakavand N, Voran JC, et al.: Allocation rules and age-dependent waiting times for kidney transplantation—an analysis of data from the German Transplantation Registry. Dtsch Arztebl Int 2024; 121: 559–65

2. Eurotransplant Statistics Report Library: https://statistics.eurotransplant.org/index.php?search_type=waiting±list&search_or gan=kidney&search_region=Germany&search_period=2018&search_cha racteristic=&search_text=&search_collection= (last accessed on 26 March 2025).

3. Otto G, Budde K, Bara C, Gottlieb J: Das Deutsche Transplantationsregister – eine Analyse der Altdaten 2006–2016. Gesundheitswesen 2024; 86: 633–9

4. Otto G, Budde K, Bara C, Gottlieb J: Unzureichende Datenqualität der Neudaten 2017–2020 des deutschen Transplantationsregisters. Dtsch Med Wochenschr 2024; 149: e76–e83