A Congestion Game Framework for Emergency Department Overcrowding

Hospitals often manage capacity and resource constraints by different strategies implemented at their system access points. Emergency departments are key portals where timely access to care is a crucial quality of service and safety metric. Individuals vying for both urgent and nonurgent care seek these services analogous to the Tragedy of the Commons archetype. In a commons, a resource is used as if it belonged to everyone. Competition for a finite, decentralized, and shared resource risks its depletion as individuals optimize their own objectives while impacting the choices of others. As a result, overall system performance degrades. Ambulance diversion, extensive wait times and patient elopements, referred to as left without being seen, epitomize overutilization and inefficient load balancing. Traditionally, many hospitals were able to build their way out of congestion. Adding capacity, however, is at odds with concerted efforts to reign in the costs of health care. In an effort to break with this tradition, we exploited insights from game theory to inform the development of policies for more effective capacity management related to emergency department use, and to highlight related challenges. We examined emergency department overcrowding within the framework of a congestion game, the El Farol Bar Game and its variants, which illustrate the Tragedy of the Commons. In a series of agent-based simulations of the games, we found no statistically significant difference between the predictions of two games and our empirical observations during our most congested time periods of nonurgent patient attendance. Given the new competitive social context of real-time publicly advertised door-to-doctor wait times, and the implications that burgeoning information technologies have for the strategies invoked by providers and patients, it seems a bar might be the best metaphor to understand emergency department congestion.