The Impact of Batching Advanced Imaging Tests in Emergency Departments

2025, Paper: "Using detailed electronic health record data from two major U.S. emergency departments (EDs), we use practice variation across physicians to uncover the operational impact of batch ordering imaging tests. Using causal inference approaches, we find that assignment of an arriving patient to an ED physician who is a “batcher” versus a “sequencer” causally increases patient length of stay, time to disposition, and the number of imaging tests ordered. We find evidence that the impact of batching on length of stay is heavily mediated by the additional imaging tests as well as probability of being admitted to the hospital post ED service, suggesting this ordering strategy may lead to more conservative clinical decision-making and critical bottlenecks in patient flow. Conversely, sequencing imaging tests by ED physicians poses an “information gain” advantage compared to batching: the information obtained from a prior test allows eliminating the need for ordering some future tests. Put together, our findings indicate that batch ordering may not be an optimal strategy for managing diagnostic imaging in emergency care, and that interventions to reduce physician discretion and behavioral tendencies in batch ordering may be warranted."