Modeling the Evolution of Interhospital Transfer: A Longitudinal Network Analysis

Interhospital transfers aim to provide super-specialty care and maintain patients' optimal health by transferring the patient to another hospital facility. As a complex undertaking, the interhospital transfer involves a multitude of factors that influence transfer formation, and transfer relationships among hospitals evolve over time. Although an extensive body of literature exists on factors determining where patients get transferred, less attention has been paid to understanding how interhospital transfer networks evolve and what important factors influence the evolution process. In this study, we empirically model the evolution process of the interhospital transfer network using a stochastic network modeling approach and identify key factors determining the network evolution. In particular, we consider digital health technologies that have great potential to assist coordinated healthcare delivery and demonstrate the role that three representative digital health technologies play in interhospital transfer. Using data from multiple databases on 178 hospitals over five years in the State of Florida, we find that both exogenous factors and endogenous network interactions influence the evolution of the interhospital transfer network. Besides identified factors, such as efficiency, distance, and relationship, digital health technologies significantly impact interhospital transfer networks' tie formation during the evolution process. Our study contributes to the literature on patient routing in healthcare operations by uncovering mechanisms of the evolution of interhospital transfer networks.