Background: The German diagnosis-related group (G-DRG) system is based on the belief that there is only one specific coding for each case. The aim of this study was to compare coding results of identical cases coded by different coding specialists.
Material and methods: Charts of six anonymous cases -- except final letter and coding -- were sent to 20 German departments of urology. They were asked to let their coding specialists do a DRG coding of these cases. The response rate was 90%.
Results: Each case was coded in a different way by each coding specialist. The DRG refunding varied by 6-23%. The coding differences were caused by different interpretations of definitions in the DRG system and also by inaccurate chart analysis.
Conclusion: The present DRG system allows a wide range of interpretation, leading to aggravation of the ongoing disputes between hospitals and insurance companies.