ED Throughput
ED throughput refers to the efficiency of patient flow through the emergency department, measured by door-to-provider time, length of stay by acuity, LWBS rate, and boarding hours — all directly affecting patient experience, safety outcomes, and hospital revenue.
What is ED Throughput?
ED throughput encompasses the full spectrum of patient flow metrics from arrival to departure or admission. Door-to-provider time targets less than 30 minutes, with the national average around 26 minutes but wide variation across facilities. The LWBS (Left Without Being Seen) rate — patients who register but leave before evaluation — should remain below 2%; high-volume urban EDs can reach 5–8%. ED length of stay for discharged patients targets under 3 hours, while boarding (admitted patients waiting in the ED for an inpatient bed) drives the national average for admitted patient LOS above 3.5 hours. Each boarding hour costs approximately $99 in ED revenue through crowding effects. The Emergency Severity Index (ESI) 5-level triage system governs resource allocation and LOS prediction by acuity category. Left-against-medical-advice (LAMA) rates and post-visit HCAHPS scores for ED encounters — covering door-to-doctor communication, pain management, and discharge instructions — round out the throughput performance picture.
Why It Matters for Healthcare Analytics
Poor ED throughput creates a compounding revenue and safety problem: boarding admits consume ED beds, increasing crowding and LWBS rates, each of which represents $500–$1,500 in lost revenue per patient. LWBS patients are also 5 times more likely to require hospitalization within 72 hours when they seek care elsewhere — making throughput a genuine patient safety issue. HCAHPS scores affected by throughput contribute to CMS Value-Based Purchasing performance.
How Vizier Tracks ED Throughput
Upload your ED registration and EHR timestamp data, then ask "What are our peak LWBS hours and which ESI levels are leaving most?" — Vizier identifies throughput bottlenecks by hour, day, and acuity level, and quantifies the revenue impact of LWBS and boarding on your ED's financial performance.