Relationship Between Emergency Department Patient Volume on Arrival and Adverse Outcomes for Admitted Patients: A...

To describe the association between concurrent patient volume in the emergency department (ED) and adverse outcomes for admitted patients.

This was a data linkage analysis using routinely collected data from Level six EDs in New South Wales Australia. Adult patients (aged ≥ 16 years) presenting to ED between 1 April 2022 and 31 March 2023 and admitted to an inpatient unit from ED were included. The exposures of interest were ED patient (total and admitted) volume at the time of patient arrival. The primary outcome was an adverse outcome, defined as 30-day all-cause mortality or intensive care unit admission from an inpatient ward. Multivariable logistic and Cox proportional hazards models were used to adjust for covariates.

There were 142,362 cases analysed. There was a relationship between ED patient volume deciles and proportion of adverse outcomes, increasing from 5% to 7%. The adjusted odds of adverse outcomes associated with the second quintile of total patient volume was 16% higher (odds ratio, OR [95% confidence interval] 1.16 [1.07-1.25]) and 26% higher in the third quintile (1.26 [1.17-1.36]) relative to the first quintile. Based on modelling, excess mortality associated with increasing ED patient volumes was estimated to be around 1000 deaths per annum.

We found a relationship between increasing ED patient volumes at the time of arrival and adverse outcomes for admitted patients.