United States' Performance on Emergency Department Throughput, 2006 to 2016.

STUDY OBJECTIVE: Studies of early data found that US emergency departments (EDs) were characterized by prolonged patient waiting, long visit times, frequent and prolonged boarding (ie, patients kept waiting in ED hallways or other space outside the ED on admission to the hospital), and patients leaving without receiving or completing treatment. We sought to assess recent trends in ED throughput nationally. METHODS: This was a retrospective cross-sectional analysis of data from the National Hospital Ambulatory Medical Care Survey from 2006 to 2016. We used survey-weighted generalized linear models to assess changes over time. The primary outcome variables were the number of visits, wait time to consult a physician, length of visit (time from arrival to leaving for home or hospital ward), boarding time, the proportion of patients leaving without being seen, the proportion treated within recommended waiting times, and the proportion dispositioned within 4, 6, and 8 hours. RESULTS: Between 2006 and 2016, the number of ED visits increased from 119.2 million to 145.6 million. During this period, annual median wait time decreased from 31 minutes (interquartile range 14 to 67) to 17 minutes (interquartile range 6 to 45). The proportion of patients who left without being seen declined from 2.0% (95% confidence interval [CI] 1.7% to 2.4%) to 1.1% (95% CI 0.8% to 1.4%). The proportion treated by a qualified practitioner within recommended waiting times increased from 75.5% (95% CI 72.7% to 78.3%) to 80.8% (95% CI 77.2% to 84.4%). Overall, there was no statistically significant change in median length of visit. However, over time, decreased proportions of the sickest patients were discharged within 4, 6, and 8 hours, whereas increased proportions of low-acuity patients were discharged within 4 hours. The distribution of patient boarding time remained fairly unchanged from 2009 to 2015, with a median of approximately 75 minutes. CONCLUSION: Overall, there was improvement in ED timeliness from 2006 to 2016. However, we observed a decrease in the proportion of the sickest patients discharged within 8 hours of arrival, although this may be due to increased ancillary testing or specially consultation over time.