Influences on emergency department length of stay for older people.
OBJECTIVE
The aim of this study was to examine the influences on emergency department (ED) length of stay (LOS) for older people and develop a predictive model for an ED LOS more than 4 h.


METHODS
This retrospective cohort study used organizational data linkage at the patient level from a major Australian health service. The study population was aged 65 years or older, attending an ED during the 2013/2014 financial year. We developed and internally validated a clinical prediction rule. Discriminatory performance of the model was evaluated by receiver operating characteristic (ROC) curve analysis. An integer-based risk score was developed using multivariate logistic regression. The risk score was evaluated using ROC analysis.


RESULTS
There were 33 926 ED attendances: 57.5% (n=19 517) had an ED LOS more than 4 h. The area under ROC for age, usual accommodation, triage category, arrival by ambulance, arrival overnight, imaging, laboratory investigations, overcrowding, time to be seen by doctor, ED visits with admission and access block relating to ED LOS more than 4 h was 0.796, indicating good performance. In the validation set, area under ROC was 0.80, P-value was 0.36 and prediction mean square error was 0.18, indicating good calibration. The risk score value attributed to each risk factor ranged from 2 to 68 points. The clinical prediction rule stratified patients into five levels of risk on the basis of the total risk score.


CONCLUSIONS
Objective identification of older people at intermediate and high risk of an ED LOS more than 4 h early in ED care enables targeted approaches to streamline the patient journey, decrease ED LOS and optimize emergency care for older people.
School of Nursing and Midwifery.|Centre for Quality and Patient Safety Research - Eastern Health Partnership.
Maryann
M
Street
Biostatistics Unit, Faculty of Health, Deakin University, Geelong.
Mohammadreza
M
Mohebbi
School of Nursing and Midwifery.|Centre for Quality and Patient Safety Research - Eastern Health Partnership.
Debra
D
Berry
Intensive Care Services, Eastern Health, Box Hill.|Intensive Care Services, Northern Health, Epping, Victoria, Australia.
Anthony
A
Cross
School of Nursing and Midwifery.|Centre for Quality and Patient Safety Research - Eastern Health Partnership.
Julie
J
Considine
D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D015331:Cohort Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004638:Emergency Treatment / Q000379:methods*; D005260:Female; D015577:Geriatric Assessment; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D016896:Treatment Outcome; D014218:Triage