Predictors and in-hospital mortality associated with prolonged emergency department length of stay in New South Wales tertiary hospitals from 2017 to 2018.

OBJECTIVE: To determine specific patient, clinical and service factors associated with increased ED length of stay and investigate whether prolonged ED length of stay, as measured by emergency treatment performance (ETP) non-compliance, is an independent predictor of all cause 30-day mortality for patients presenting to, and admitted from ED.

METHODS: This was a retrospective analysis of linked state-wide emergency, inpatient and death data from New South Wales. All patients who presented to a tertiary level public hospital (level 5 or 6) ED and admitted to an in-patient unit were included. Outcomes were the proportion of admitted patients who met ETP targets, and 30-day all-cause mortality.

RESULTS: A total of 697 600 eligible cases were identified and analysed. The odds of meeting ETP benchmarks were 62% lower in those with complex or multiple medical comorbidities (odds ratio 0.38, 95% confidence interval 0.37-0.40, P < 0.001) compared with patients with no medical comorbidities. Admission under psychiatry, surgical and oncology service-related groups were associated with decreased ETP. The hazard ratio for 30-day all-cause mortality over time was 28% higher in those not meeting ETP benchmarks after adjusting for age, triage category, comorbidities, ICU and service-related group (hazard ratio 1.28, 95% confidence interval 1.26-1.30, P < 0.001).

CONCLUSION: Patients with complex and multiple medical comorbidities, and those admitted under certain service-related groups such as psychiatry, surgery and oncology were found to have poorer ETP performance. Overall, failure to meet ETP was associated with increased mortality after adjusting for age, case-mix, comorbidities and acuity.