Patterns of Ophthalmology-related Interfacility Transfers to the Emergency Department by Temporal Trends

Background: Interfacility transfer patients are associated with inferior outcomes, higher costs, and emergency department (ED) overcrowding. Previous studies have analyzed the general trends influencing interfacility transfers, but the patterns affecting ophthalmology-related transfer rates remain unclear. The purpose of this study was to identify and quantify the patterns of interfacility ophthalmology-specific transfers to the ED by temporal trends and to determine the type of ophthalmic services required by the transferred population. Methods: All patients transferred to the ED of a single level 1 trauma center because of ophthalmology-related complaints from 2016 to 2023 were analyzed retrospectively. Transfer and nontransfer patient visits were sorted by season, day of the week, time of day, and federal holiday status. Results: A total of 2,660 patients were included. The overall volumes of ophthalmology-related interfacility transfers and direct ED visits were highest during the summer and lowest during the winter (P < 0.05). Ophthalmology-related interfacility transfers were highest on weekend days and lowest on Wednesdays, representing 40% and 10.1% of total transfers, respectively (P < 0.01). Nontransfer ophthalmology-related ED visits were more equally distributed throughout the week (P = 0.16). Over half of all transfers occurred during the afternoon (52.9%); however, most direct ED visits were equally distributed between mornings (44.7%) and afternoons (44.1%). Statistically significant differences regarding the time of the day were apparent in both groups (P < 0.05). Additionally, the most common ophthalmic category among interfacility transfer patients was trauma to the eye (32.1%), followed by oculoplastic maladies (27.5%). Glaucoma (2.9%) and neuro-ophthalmology (0.1%) received fewer number of patients. Conclusions: Interfacility transfer patients represent a large proportion of the ophthalmology-related ED volume on weekends and during the night shift, which could contribute to ED overcrowding and staffing shortages.