Beyond Resource Expansion: Building Resilient Hospital Surge Capacity for Sustained Crisis Response

Background: Hospital surge-capacity assessment has traditionally emphasized the expansion of beds, staff, equipment, and medical supplies, but provides limited insight into how these resources are transformed into sustained operational capabilities under uncertainty. This study develops a resilience-oriented function-capability framework to assess hospital surge capacity from a systems perspective. Methods: Hospital surge capacity theory and hospital resilience theory were integrated to define 5 capability dimensions: functional reconfiguration, resource configuration, operational continuity, regional coordination, and collaborative optimization. FRAM was used to model 24 operational functions and their couplings under 4 synthesized surge scenarios. An improved K-shell algorithm quantified structural importance, while Monte Carlo derived functional-performance uncertainty was represented by truncated-normal prior distributions. Bayesian network was then used for performance assessment, propagation, sensitivity, and robustness analyses. Results: The estimated overall surge-capacity performance was 0.5479, 0.5631, 0.5723, and 0.5867 for S₁-S₄, respectively. Influential functional nodes differed across scenarios, whereas operational continuity capability consistently showed the greatest sensitivity to overall performance. Cumulative 50% degradation of structurally important functions reduced overall surge capacity by 23.54%, 16.91%, 20.51%, and 19.75% in S₁-S₄, respectively. Robustness analyses showed that the main scenario ordering and principal influential nodes remained generally stable under alternative modeling assumptions. Conclusions: Hospital surge capacity depends not only on resource availability but also on the coordinated performance of interconnected operational functions. The proposed FRAM-K-shell-BN framework separates structural importance from functional-performance uncertainty and links function level variability to capability level and overall system performance, providing a structured approach for assessing hospital surge capacity under uncertain emergency conditions.