Estimates of throughput and utilization at freestanding compared to low-volume hospital-based emergency departments

Our investigation compared throughput metrics and utilization measures for freestanding emergency departments (FSEDs) versus hospital-based emergency departments (HBEDs) of similar volumes in the United States.

This study is a cross sectional survey of 183 FSEDs and 317 HBEDs located across the United States using the Emergency Department Benchmarking Alliance (EDBA) Database. We measured common emergency department (ED) throughput metrics. Primary outcomes included overall length of stay, length of stay for admitted, and length of stay for treated and released patients. Outcomes were weighted based on the proportion of ED volume per facility as per a prior pilot study. Multiple linear regression analysis was used to adjust for measured differences between FSEDs and HBEDs. The variables that were controlled for in regression analysis included geographic location of the ED (urban, suburban, and rural), percent of high acuity capacity, ED volume, percentage of patients arriving via emergency medical services (EMS), and percentage of pediatric patients.

Nationally, the median length of stay in minutes (104.2 vs 140.0), length of stay for treated and released patients (98.6 vs 122.9), door-to-bed (4.0 vs 8.0), door-to-doctor (11.0 vs 16.0), percentage of patients admitted through the ED (4.0 vs 11.0), and percentage of patients leaving the ED without being seen (LWBS) (0.9 vs 1.5), were significantly lower at FSEDs compared to HBEDs (P < 0.0001 for all comparisons). Length of stay for admitted patients (265.9 vs 241.8) and median boarding time (96.8 vs. 71.3) were significantly lower in HBEDs compared to FSEDs. X-ray, computed tomography, and ECG utilization per 100 patients was significantly lower at the FSEDs compared to HBEDs. Multiple linear regression analysis demonstrated that the length of stay for treated and released patients was 8.67 minutes shorter for FSEDs as compared to HBEDs (95% confidence interval [CI] = -1.4 to -16.0). The length of stay for admitted patients was 44 minutes longer for FSEDs as compared to HBEDs (95% CI = 25.5 to 63.0).

In this study of similarly sized EDs in the United States, throughput metrics for FSEDs tended to be significantly shorter from the arrival of the patient until their departure, except for patients requiring hospital admission. For measures favoring FSEDs, throughput times range from 20%-50% shorter than HBEDs.