Development of lengths of stay and DRG cost weights in dermatology from 2003 to 2006.

Background: The G-DRG per case payments are calculated annually on the basis of present output and cost data provided from German hospitals. The economic valuation of dermatology-related DRGs depends largely on inpatients' length of stay. At present, longitudinal analyses of dermatologic hospital data considering the development of length of stay under DRG conditions are not available.
Methods: A multicenter, longitudinal study of clinical data from hospitals with different care levels was performed (n = 23). Frequent and relevant dermatologic diagnoses were grouped and analyzed over a time period of four years (2003-2006). The development of lengths of stay and of G-DRG cost weights were studied in detail. Descriptive statistical methods were applied.
Results: After introduction of DRG, the data reveal a) reduction of length of stay in inpatient dermatology and b) after an initial abrupt rise, DRG valuation of dermatologic groups moderately decreased over time. Both trends changed most rapidly in the early years but reached a stable niveau in 2006. The study furthermore points out that not only length of stay, but also other type of costs influence DRG calculations.
Conclusions: German dermatology reflects the international trend showing reductions of length of stay after introduction of a DRG-based hospital funding system. The DRG calculation and valuation of inpatient services depend on the duration of hospital stay. However, increasing per diem costs resulting from higher performances of every inpatient bed day are also taken into account. Further reduction of length of stay must not threaten the quality of inpatient care in dermatology.