Association between age and length of stay in the emergency department in a tertiary care hospital: a retrospective observational study.

Background: Older patients' attendances at EDs are rising. There are concerns that these individuals have prolonged stays, which have been shown to be associated with adverse clinical outcomes. We assessed the length of stay in older patients in a single ED in Singapore.

Methods: This was an observational retrospective study of ED attendances between 2017 and 2019 at the Singapore General Hospital (SGH) using the SGH ED database. The primary outcome was ED length of stay, with prolonged stay defined as 4 hours or more. The association between age (categorised into 18-44, 45-64, 65-84 and 85+) and length of stay was analysed using a mixed-effects logistic regression adjusting for variables like gender, ethnicity and triage acuity. Associations are expressed as adjusted ORs (AOR) with 95% CI. A subgroup analysis was performed for all considered variables.

Results: 391 171 patients qualified for analysis; median age 57 years (IQR 37-70) and 51.5% male. The median length of stay increased across age categories (age 18-44, 3.53 hours; 45-64, 4.04 hours; 65-84, 4.32 hours; and 85+, 4.46 hours). Using patients aged 18-44 as a reference, the AORs for prolonged length of stay by age group were 45-64 AOR 1.17 (95% CI 1.13 to 1.21), 65-84 AOR 1.26 (95% CI 1.21 to 1.30) and 85+ AOR 1.25 (95% CI 1.18 to 1.31). In the subgroup analysis, there was no association between age and length of stay for patients admitted, having multiple comorbidities, having blood tests or having high acuity scores.

Conclusion: In this Singaporean tertiary hospital, older patients had increased median stays and were more likely to stay in the ED for more than 4 hours. However, this did not apply in some subpopulations. This potentially suggests the need for systematic changes in discharge planning and triaging to reduce prolonged stays and their consequences for older patients.