Structural-Fiscal Alignment in German Hospital Reform: Network Analysis of Service Group Prerequisites and Comparative Policy Scenarios

BackgroundGermanys Hospital Care Improvement Act (Krankenhausversorgungsverbesserungsgesetz, KHVVG) establishes 65 hospital service groups (Leistungsgruppen, LGs) with codified structural prerequisites, creating a directed dependency network. It remains unclear whether this regulatory structure appropriately reflects the economic importance of different services, particularly for specialties serving aging populations. MethodsWe modeled KHVVG dependencies as a directed network and calculated centrality metrics for all 65 LGs. Using elastic net regression, we related network position to LG-specific revenue data (2021) as a proxy for real-world service importance. Residuals between actual and network-predicted revenue quantified structural-fiscal alignment. We compared three policy scenarios: baseline KHVVG structure, KHAG reform (eliminating infectious diseases and emergency medicine service groups), and a hypothetical GBA scenario (adding geriatrics as mandatory prerequisite for hip replacement services). ResultsThe regression model explained 56.6% of revenue variance (R{superscript 2}=0.566). Enablement index ({beta}=+0.38) and weighted in-degree ({beta}=-0.84) were primary predictors. Twenty-one LGs (35.6%) showed good alignment (|residual| <0.5 log units), including high-revenue services such as general internal medicine ({euro}9.8B, residual +0.03) and general surgery ({euro}12.1B, residual -0.06). Geriatrics (LG56) exhibited the largest positive residual (+2.24 log units), with actual revenue of {euro}1.84B versus network-predicted {euro}195M--a 9.4-fold gap. The GBA scenario reduced geriatrics residual to +1.52 (-0.72 change, 32% improvement) by transforming it from pure sink node to gateway node. The KHAG scenario produced negligible change (-0.002). ConclusionsNetwork analysis reveals systematic structural-fiscal misalignment for geriatrics despite high service utilization. Strategic prerequisite placement achieves substantially greater alignment improvement than service group elimination. These findings demonstrate a quantitative approach for evaluating how regulatory frameworks recognize service importance, with potential implications for hospital planning in aging populations. HighlightsO_LINetwork analysis quantifies structural-fiscal alignment in German hospital reform C_LIO_LI35.6% of service groups show good alignment between network position and revenue C_LIO_LIGeriatrics shows mathematical 9.4-fold gap: {euro}1.84B actual vs. {euro}195M predicted revenue C_LIO_LIStrategic prerequisite addition reduces alignment gap by 32% (in network-based predictions) C_LIO_LIMethod provides generalizable framework for evaluating health policy reforms in terms of network metrics C_LI