Evolutionary drivers of China’s interprovincial healthcare service network: a temporal exponential random graph analysis of provincial panel data

Background High-quality healthcare resources remain unevenly distributed across China, while cross-provincial care seeking, teleconsultation, and regional medical collaboration are increasingly common. Existing studies have mainly explained regional disparities in terms of resource endowments, geographic proximity, and spatial accessibility, with less attention to network structure, tie formation and persistence, and changes during public health crises. Methods Using panel data for 31 provincial-level administrative units in mainland China from 2009 to 2023, we constructed a directed interprovincial healthcare service association network with a modified gravity model. Social network analysis, temporal exponential random graph models (TERGMs), and separable temporal exponential random graph models (STERGMs) were used to examine network structure, endogenous mechanisms, sender and receiver effects, and differences before and during the COVID-19 pandemic. Results The network shifted from expansion and integration toward contraction and differentiation. The number and density of ties increased from 2009 to 2013, declined after 2014, and fell markedly in 2019, while rising hierarchy indicated stronger core-periphery differentiation. Beijing, Shanghai, and Jiangsu formed the core of tie reception and path control; Zhejiang, Fujian, Henan, and Guangdong served as regional bridges; and the Northeast, Northwest, and several border regions remained weakly embedded. Reciprocity was positive in both formation and persistence and was the principal endogenous driver of network evolution. Transitivity mainly promoted new ties, whereas negative cyclicality indicated localized clustering, hierarchy, and asymmetric flows. Digital infrastructure and transport accessibility promoted outgoing ties in the aggregate model, whereas fiscal autonomy and population aging reduced them. Transport accessibility mainly promoted tie formation, while government support, fiscal autonomy, and population aging were more closely associated with persistence. The public health crisis increased reliance on reciprocity, transport accessibility, and fiscal capacity. Robustness and goodness-of-fit analyses supported these findings. Conclusion China’s interprovincial healthcare service network is a dynamic relational system jointly shaped by reciprocal cooperation, transport accessibility, fiscal capacity, digital infrastructure, and external shocks. Policy should reduce institutional costs, strengthen reciprocal cooperation, insurance payment and digital interoperability, reorient core nodes from resource-absorbing centers toward capacity-diffusion hubs, and improve network access and resilience in underserved regions.