Primary Performance Indicators for Emergency Departments
The Centers for Medicare and Medicaid Services mandates five core ED performance measures that hospitals must report: median time from ED arrival to departure for discharged patients, door-to-diagnostic evaluation by a qualified medical professional, patients who leave before being seen (LWBS), median time from ED arrival to departure for admitted patients, and median time from admit decision to departure for admitted patients. 1
Regulatory-Mandated Core Metrics
The Joint Commission and CMS have established these indicators as patient safety issues, particularly recognizing that ED crowding directly impacts quality of care across multiple domains including safety, timeliness, efficiency, and equitability 1. These measures became mandatory reporting requirements in 2014 1.
Time-Based Performance Indicators
Primary time metrics include:
- Time to Provider (TTP): Duration from ED arrival to initial evaluation by a qualified medical professional 2, 3
- Time to Disposition (TTD): Interval from ED arrival to final disposition decision (admit, discharge, or transfer) 2, 3
- Length of Stay (LOS): Total time from ED arrival to physical departure, measured separately for:
- Door-to-admit decision time: Time from arrival to the decision to admit 1
- Admit decision to departure time: Boarding interval after admission decision 1
Access and Flow Indicators
Left Without Being Seen (LWBS) rate is a critical quality metric reflecting both access barriers and patient safety concerns 1, 3. This proportion-based measure indicates patients who departed before medical evaluation and correlates strongly with ED crowding 1.
Patient elopement rates beyond LWBS (patients who leave after initial contact but before treatment completion) represent additional access failures 1.
Disease-Specific Time Targets
STEMI Performance Measures
For ST-elevation myocardial infarction, specific time benchmarks exist 1:
- Door-to-balloon time ≤90 minutes for primary PCI at PCI-capable facilities 1
- Door-to-fibrinolytic time ≤30 minutes at non-PCI-capable facilities when transfer time exceeds 120 minutes 1
- Door-to-ECG time: Should be performed immediately upon arrival 1
- ED arrival to ED departure time for transferred STEMI patients 1
Quality and Safety Indicators
Medication errors correlate directly with ED crowding levels, making error rates an important performance indicator 1. Studies demonstrate associations between crowding and preventable medical errors across both adult and pediatric populations 1.
Timeliness of critical interventions includes 1:
- Time to analgesic administration (particularly for pain crises and acute abdominal pain)
- Time to antibiotic administration for conditions like community-acquired pneumonia
- Delays in these interventions are associated with ED crowding and represent quality deficits
Patient-Centered Outcomes
Patient satisfaction serves as a quality indicator, though it requires careful analysis beyond simple scores 4. Satisfaction correlates with perceived wait times (which differ from actual wait times), staff communication quality, and understanding of care processes 5.
Cost metrics have been linked to ED crowding in large-scale studies, making efficiency measures relevant performance indicators 1.
Operational Definitions
A 2011 consensus summit of emergency medicine experts established standardized definitions for ED operational metrics, aligning with CMS, Emergency Nurses Association, and National Quality Forum standards 2. These definitions ensure consistent measurement across institutions.
Common Pitfalls in Performance Measurement
Avoid measuring only individual metrics in isolation 6. A 2020 scoping review identified 202 individual ED performance indicators, but comprehensive assessment requires examining outcomes across five domains: time, proportion, process, cost, and clinical outcomes 6.
Heterogeneity in measurement methods creates challenges 6. Performance measurement involves both automated information technology mechanisms and manual data collection, reflecting the multifaceted nature of ED care 6.
Context matters for intervention effectiveness 3. Meta-analysis shows that strategies like point-of-care testing and triage liaison physicians reduce time metrics, but effectiveness varies by practice environment and must be tailored appropriately 3.