Clinical and longitudinal patterns of frequent presenters to emergency departments: A multi-centre data linkage analysis.

OBJECTIVE: To describe clinical characteristics and longitudinal patterns of representation in a cohort of patients who frequently present to EDs for care. METHODS: A retrospective data analysis linking routinely collected ED data across three hospitals. The study population consisted of patients who presented to any ED on 10 or more occasions in any continuous 365-day period from 1 July 2015 to 30 June 2021. Presenting complaints were divided into those with any mental health, drug and alcohol, or social presentations (MHDAS group) and those without (non-MHDAS group). Outcomes of interest were number of presentations as well as temporal and facility clustering of presentations. A per patient regression analysis was performed to identify independent risk factors for increased presentations. RESULTS: Presentations by 1640 frequent ED presenters in the study constituted 4.6% of total ED presentations. MHDAS study group were younger, predominantly English speaking, twice as likely to be married, had lower hospital admission rates and almost three times as many of them did not wait for treatment. Statistically significant differences were also found between these groups regarding presentation clustering, facility entropy, each of the four categories of the number of ED presentations, and Index of Relative Socio-Economic Advantage and Disadvantage. CONCLUSION: Representations associated with MHDAS have a different trajectory of representation episodes compared to non-MHDAS group. Escalating number of presentations and clustering are important predictors of future representation numbers. Those 'did not waits' who appear to be representing would be the highest risk of ongoing and persistent representations in the future and should be the target of early interventions to ensure they are accessing appropriate care before this happens.

24 hours - Life in the E.R.: A state-wide data linkage analysis of in-patients with prolonged emergency department length of stay in New South Wales, Australia.

OBJECTIVE: Describe the characteristics and predictors of mortality for patients who spend more than 24 h in the ED waiting for an in-patient bed and compare baseline clinical and demographic characteristics between tertiary and non-tertiary hospitals. METHODS: This was a state-wide analysis data linkage analysis of adult (age >16 years) ED presentations across New South Wales from 2019 to 2020. Cases were included if their mode of separation from ED indicated admission to an in-patient unit including critical care ward and their ED length of stay was greater than or equal to 24 h. Cases were categorised by service-related groups based on principle diagnosis. RESULTS: A total of 26 854 eligible cases were identified. The most common diagnosis groups were psychiatry, cardiology and respiratory. The odds ratio (OR) for 30-day all-cause mortality in admitted patients with an ED length of stay greater than 24 h were highest in those aged >75 years (OR 15.18, 95% confidence interval [CI] 9.99-23.07, P < 0.001), oncology (OR 10.45, 95% CI 7.93-13.77, P < 0.001) and haematology patients (OR 2.95, 95% CI 2.01-4.33, P < 0.001). CONCLUSION: Interventions and models of care to address ED access block need to focus on mental health patients, older patients particularly those with cardiorespiratory illness and oncology and haematology patients for whom risk of mortality is disproportionately higher.

Does volume or occupancy influence emergency access block? A multivariate time series analysis from a single emergency department in Sydney, Australia during the COVID-19 pandemic.

OBJECTIVE: The study aims to determine whether ED presentation volume or hospital occupancy had a greater impact on ED performance before and during the COVID-19 health response at a tertiary referral hospital in Sydney, Australia. METHODS: Single centre time series analysis using routinely collected hospital and ED data from January 2019 to September 2020. The primary outcome was ED access block measured by emergency treatment performance (ETP; i.e. percentage of patients who were discharged or transferred to a ward from ED within 4 h of ED arrival time). Secondary outcomes were hospital occupancy, elective theatre cases and ambulance ramping. Multivariate time series analysis was performed using vector autoregression, to model effects of changes in various endogenous and correlated variables on ETP. RESULTS: There was an increase in ETP, drop in ED presentations and decrease in hospital occupancy between April and June 2020. Elective surgery and hospital occupancy had significant effects up to 2 days prior on ETP, while there were no significant effects of either ED or ambulance presentations on ETP. Hospital occupancy itself increased with ED presentations after 2-4 days and decreased with elective surgery after 1 day. Shocks (a one standard deviation increase) in hospital occupancy had a peak impact nearly two times greater compared to ED presentations (-1.43, 95% confidence interval -1.92, -0.93 vs -0.73, 95% confidence interval -1.21, -0.25). CONCLUSION: The main determinants of the reduction of ED overcrowding and access block during the pandemic were associated with reductions in hospital occupancy and elective surgery levels, and more research is required to assess more complex associations beyond the scope of this manuscript.

Incidence and outcomes of aortic dissection for emergency departments in New South Wales, Australia 2017-2018: A data linkage study.

OBJECTIVE: The aims of the present study were to describe the age-specific incidence and 30-day mortality of aortic dissection patients presenting to the EDs in New South Wales (NSW). METHODS: This was a data linkage study involving emergency, inpatient and death registry administrative data from NSW. RESULTS: The present study found 273 instances of aortic dissection in NSW from July 2017 to July 2018. Calculated incidence was 3.47 per 100 000. Incidence increased exponentially with age. The 30-day mortality rate among this cohort was 35.53% (n = 97). Mortality was significantly associated with age and pre-existing comorbidity burden, but was not associated with gender, level of hospital or time of presentation. CONCLUSIONS: The present study found the incidence of aortic dissection within the NSW population to be 3.4 per 100 000. The incidence of aortic dissection in our population increased from 8.6 per 100 000 for people aged between 60 and 80 years to 32 per 100 000 for those aged over 80 years.

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.

The Sydney triage to admission risk tool (START) to improve patient flow in an emergency department: a model of care implementation pilot study.

BACKGROUND: The Sydney Triage to Admission Risk Tool (START) is a validated clinical analytics tool designed to estimate the probability of in-patient admission based on Emergency Department triage characteristics. METHODS: This was a single centre pilot implementation study using a matched case control sample of patients assessed at ED triage. Patients in the intervention group were identified at triage by the START tool as likely requiring in-patient admission and briefly assessed by an ED Consultant. Bed management were notified of these patients and their likely admitting team based on senior early assessment. Matched controls were identified on the same day of presentation if they were admitted to the same in-patient teams as patients in the intervention group and same START score category. Outcomes were ED length of stay and proportion of patients correctly classified as an in-patient admission by the START tool. RESULTS: One hundred and thirteen patients were assessed using the START-based model of care. When compared with matched control patients, this intervention model of care was associated with a significant reduction in ED length of stay [301 min (IQR 225-397) versus 423 min (IQR 297-587) p < 0.001] and proportion of patients meeting 4 h length of stay thresholds increased from 24 to 45% (p < 0.001). CONCLUSION: In this small pilot implementation study, the START tool, when used in conjunction with senior early assessment was associated with a reduction in ED length of stay. Further controlled studies are now underway to further examine its utility across other ED settings.

Diagnoses, damned diagnoses and statistics: Dealing with disparate diagnostic coding systems within the New South Wales Emergency Department Data Collection.

OBJECTIVES: The aims of the present study were to describe the distribution of Systematised Nomenclature of Medicine - Clinical Terms (SNOMED-CT) codes used in the current New South Wales Emergency Department Data Collection (NSW EDDC) and classify duplicate and redundant terms into clinically meaningful sub-groups for future analyses. METHODS: This was an analysis of ED diagnosis codes using a large state-wide administrative ED dataset between 2015 and 2018. RESULTS: A total of 7.4 million (77%) of ED episode diagnoses were coded with SNOMED-CT. Of those coded with SNOMED-CT, 12 152 unique codes were identified. Around 1000 of the most frequently used codes accounted for 90% of the presentations coded with SNOMED-CT and 5000 codes accounted for 99.8% of these. Around 7000 codes were deemed to be redundant, and duplication in terms exists across all sub-groups. CONCLUSION: The use of SNOMED-CT in the NSW EDDC has resulted in substantial use of non-specific, duplicate and redundant codes, limiting the capacity of the NSW EDDC to be used for effective data analysis.

Extending the Sydney Triage to Admission Risk Tool (START+) to predict discharges and short stay admissions.

OBJECTIVE: This study aims to validate previously reported triage tool titled Sydney Triage to Admission Risk Tool (START+) and investigate whether an extended version of the tool could be used to identify and stream appropriate short stay admissions to ED observation units or specialised short stay inpatient wards. METHODS: This was a prospective study at two metropolitan EDs in Sydney, Australia. Consecutive triage encounters were observed by a trained researcher and START scores calculated. The primary outcome was length of stay <48 hours. Multivariable logistic regression was used to estimate area under curve of receiver operator characteristic (AUROC) for START scores. The original START tool was then extended to include frailty and multiple or major comorbidities as additional variables to assess for further predictive accuracy. RESULTS: There were 894 patients analysed during the study period. Of the 894 patients, there were 732 patients who were either discharged from ED or admitted for <2 days. The AUROC for the original START+ tool was 0.80 (95% CI 0.77 to 0.83). The presence of frailty was found to add a further five points and multiple comorbidities added another four points on top of the START score, and the AUROC for the extended START score 0.84 (95% CI 0.81 to 0.88). CONCLUSION: The overall performance of the extended ED disposition prediction tool that included frailty and multiple medical comorbidities significantly improved the ability of the START tool to identify patients likely to be discharged from ED or require short stay admission <2 days. TRIAL REGISTRATION NUMBER: ACTRN12618000426280.

Presentations to NSW emergency departments with self-harm, suicidal ideation, or intentional poisoning, 2010-2014.

OBJECTIVE: To evaluate population trends in presentations for mental health problems presenting to emergency departments (EDs) in New South Wales during 2010-2014, particularly patients presenting with suicidal ideation, self-harm, or intentional poisoning. DESIGN, SETTING AND PARTICIPANTS: This was a retrospective, descriptive analysis of linked Emergency Department Data Collection registry data for presentations to NSW public hospital EDs over five calendar years, 2010-2014. Patients were included if they had presented to an ED and a mental health-related diagnosis was recorded as the principal diagnosis. MAIN OUTCOME MEASURES: Rates of mental health-related presentations to EDs by age group and calendar year, both overall and for the subgroups of self-harm, suicidal ideation and behaviour, and intentional poisoning presentations. RESULTS: 331 493 mental health-related presentations to 115 NSW EDs during 2010-2014 were analysed. The presentation rate was highest for 15-19-year-old patients (2014: 2167 per 100 000 population), but had grown most rapidly for 10-14-year-old children (13.8% per year). The combined number of presentations for suicidal ideation, self-harm, or intentional poisoning increased in all age groups, other than those aged 0-9 years; the greatest increase was for the 10-19-year-old age group (27% per year). CONCLUSIONS: The rate of mental health presentations to EDs increased significantly in NSW between 2010 and 2014, particularly presentations by adolescents. Urgent action is needed to provide better access to adolescent mental health services in the community and to enhance ED models of mental health care. The underlying drivers of this trend should be investigated to improve mental health care.

The Sydney Triage to Admission Risk Tool (START): A prospective validation study.

OBJECTIVE: The present study aims to prospectively validate the Sydney Triage to Admission Risk Tool (START) to predict ED disposition. METHODS: This was a prospective validation study at two metropolitan EDs in Sydney, Australia. Consecutive triage encounters were observed by a trained researcher and START scores calculated. The primary outcome was patient disposition (discharge or inpatient admission) from the ED. Multivariable logistic regression was used to estimate area under curve of receiver operator characteristic (AUC ROC) for START scores as well as START score in combination with other variables such as frailty, general practitioner referral, overcrowding and major medical comorbidities. RESULTS: There were 894 patients analysed during the study period. The START score when applied to the data had AUC ROC of 0.80 (95% CI 0.77-0.83). The inclusion of other clinical variables identified at triage did not improve the overall performance of the model with an AUC ROC of 0.81 (95% CI 0.78-0.84) in the present study. CONCLUSION: The overall performance of the START tool with respect to model discrimination and accuracy has been prospectively validated. Further clinical trials are required to test the clinical effectiveness of the tool in improving patient flow and overall ED performance.

Influenza-associated delays in patient throughput and premature patient departure in emergency departments in New South Wales, Australia: A time series analysis.

OBJECTIVES: Influenza outbreaks cause overcrowding in EDs. We aimed to quantify the impact of influenza on the National Emergency Access Targets and premature patient departure in New South Wales, Australia. METHODS: This was a retrospective observational study of 11 million presentations to 115 hospitals during 2010-2014, using routinely collected administrative records. A time series generalised additive regression model was used to assess the correlation between weekly influenza activity and the weekly proportion of patients leaving the ED in >4 h and the proportion that departed before commencing or completing treatment ('did not wait'), after controlling for background winter and holiday effects. RESULTS: During 2011-2014, peak annual circulating influenza was associated with the peak weekly proportion of presentations that left in >4 h. The maximum estimated absolute weekly change in that proportion was 3.88 (95% confidence interval 3.02-4.74) percentage points in 2014. For presentations that did not wait, influenza circulation was associated with statistically significant increases in all years, with a maximum weekly value of 2.68 (95% confidence interval 2.31-3.06) percentage points in 2012. CONCLUSIONS: Circulating influenza was associated with sustained increases and peaks in delayed patient throughput and premature patient departures. Influenza surveillance information may assist with development of health system and hospital workforce planning and bed management activities.

Emergency Department demand associated with seasonal influenza, 2010 through 2014, New South Wales, Australia.

INTRODUCTION: Influenza's impact on health and health care is underestimated by influenza diagnoses recorded in health-care databases. We aimed to estimate total and non-admitted influenza-attributable hospital Emergency Department (ED) demand in New South Wales (NSW), Australia. METHODS: We used generalized additive time series models to estimate the association between weekly counts of laboratory-confirmed influenza infections and weekly rates of total and non-admitted respiratory, infection, cardiovascular and all-cause ED visits in NSW, Australia for the period 2010 through 2014. Visit categories were based on the coded ED diagnosis or the free-text presenting problem if no diagnosis was recorded. RESULTS: The estimated all-age, annual influenza-attributable respiratory, infection, cardiovascular and all-cause visit rates/100 000 population/year were, respectively, 120.6 (99.9% confidence interval [CI] 102.3 to 138.8), 79.7 (99.9% CI: 70.6 to 88.9), 14.0 (99.9% CI: 6.8 to 21.3) and 309.0 (99.9% CI: 208.0 to 410.1). Among respiratory visits, influenza-attributable rates were highest among < 5-year-olds and ≥ 85-year-olds. For infection and all-cause visits, rates were highest among children; cardiovascular rates did not vary significantly by age. Annual rates varied substantially by year and age group, and statistically significant associations were absent in several years or age groups. Of the respiratory visits, 73.4% did not require admission. The non-admitted proportion was higher for the other clinical categories. Around 1 in 100 total visits and more than 1 in 10 respiratory or infection visits were associated with influenza. DISCUSSION: Influenza is associated with a substantial and annually varying burden of hospital-attended illness in NSW.

Age-related trends in injury and injury severity presenting to emergency departments in New South Wales Australia: Implications for major injury surveillance and trauma systems.

OBJECTIVES: To describe population based trends and clinical characteristics of injury related presentations to Emergency Departments (EDs). DESIGN AND SETTING: A retrospective, descriptive analysis of de-identified linked ED data across New South Wales, Australia over five calendar years, from 2010 to 2014. PARTICIPANTS: Patients were included in this analysis if they presented to an Emergency Department and had an injury related diagnosis. Injury severity was categorised into critical (triage category 1-2 and admitted to ICU or operating theatre, or died in ED), serious (admitted as an in-patient, excluding above critical injuries) and minor injuries (discharged from ED). MAIN OUTCOME MEASURES: The outcomes of interest were rates of injury related presentations to EDs by age groups and injury severity. RESULTS: A total of 2.09 million injury related ED presentations were analysed. Minor injuries comprised 85.0%, and 14.1% and 1.0% were serious and critical injuries respectively. There was a 15.8% per annum increase in the rate of critical injuries per 1000 population in those 80 years and over, with the most common diagnosis being head injuries. Around 40% of those with critical injuries presented directly to a major trauma centre. CONCLUSION: Critical injuries in the elderly have risen dramatically in recent years. A minority of critical injuries present directly to major trauma centres. Trauma service provision models need revision to ensure appropriate patient care. Injury surveillance is needed to understand the external causes of injury presenting to hospital.

Feeling the HEAT: Using Hourly Emergency Activity Tracking to demonstrate a novel method of describing activity and patient flow.

OBJECTIVE: The objective of the present study is to demonstrate a novel method of mapping ED activity to analyse patterns presentations, occupancy and performance trends. METHODS: This was a retrospective, descriptive analysis of de-identified and linked ED presentations across NSW, Australia, over five calendar years, 2010-2014. It was undertaken as part of the Demand for Emergency Services Trend in Years 2010-2014 (DESTINY) study. The DESTINY project analysed 10.8 million presentations during 2010-2014. Hourly Emergency Activity Tracking (HEAT) maps were generated to visually represent and analyse the number of emergency arrivals to ED occupancy and proportion of patients leaving the ED within 4 h per hour of day across consecutive months of the year. RESULTS: HEAT maps provided a means of visually representing ED activity to demonstrate hour-to-hour trends in presentations, occupancy and performance between 2010 and 2014. This analysis has shown that the most marked increase in presentations per hour has occurred during the 10.00-14.00 hour period, associated with an improvement in ED performance during the same period. CONCLUSION: HEAT maps may be used to facilitate further analyses of ED demand, patterns of patient presentations and patient flow and future health system redesign.

The Sydney Triage to Admission Risk Tool (START) to predict Emergency Department Disposition: A derivation and internal validation study using retrospective state-wide data from New South Wales, Australia.

BACKGROUND: Disposition decisions are critical to the functioning of Emergency Departments. The objectives of the present study were to derive and internally validate a prediction model for inpatient admission from the Emergency Department to assist with triage, patient flow and clinical decision making. METHODS: This was a retrospective analysis of State-wide Emergency Department data in New South Wales, Australia. Adult patients (age ≥ 16 years) were included if they presented to a Level five or six (tertiary level) Emergency Department in New South Wales, Australia between 2013 and 2014. The outcome of interest was in-patient admission from the Emergency Department. This included all admissions to short stay and medical assessment units and being transferred out to another hospital. Analyses were performed using logistic regression. Discrimination was assessed using area under curve and derived risk scores were plotted to assess calibration. RESULTS: 1,721,294 presentations from twenty three Level five or six hospitals were analysed. Of these 49.38% were male and the mean (sd) age was 49.85 years (22.13). Level 6 hospitals accounted for 47.70% of cases and 40.74% of cases were classified as an in-patient admission based on their mode of separation. The final multivariable model including age, arrival by ambulance, triage category, previous admission and presenting problem had an AUC of 0.82 (95% CI 0.81, 0.82). CONCLUSION: By deriving and internally validating a risk score model to predict the need for in-patient admission based on basic demographic and triage characteristics, patient flow in ED, clinical decision making and overall quality of care may be improved. Further studies are now required to establish clinical effectiveness of this risk score model.

Major trauma mortality in rural and metropolitan NSW, 2009-2014: a retrospective analysis of trauma registry data.

OBJECTIVE: To determine trends in crude and risk-adjusted mortality for major trauma patients injured in rural or metropolitan New South Wales, 2009-2014. DESIGN: A retrospective analysis of NSW statewide trauma registry data. PARTICIPANTS: Adult patients (aged 16 years or more) who presented with major trauma (Injury Severity Scores greater than 15) to a NSW hospital during 2009-2014. MAIN OUTCOME MEASURES: The main covariate of interest was geographic location of injury (metropolitan v rural/regional areas). Inpatient mortality was analysed by multivariable logistic regression. RESULTS: Data for 11 423 eligible patients were analysed. Inpatient mortality for those injured in metropolitan locations was 14.7% in 2009 and 16.1% in 2014 (P = 0.45). In rural locations, there was a statistically significant decline in in-hospital mortality over the study period, from 12.1% in 2009 to 8.7% in 2014 (P = 0.004). Risk-adjusted mortality for those injured in a rural location was lower in 2013 than during 2009, but remained stable for those injured in metropolitan locations. CONCLUSION: Crude and risk-adjusted mortality after major trauma have remained stable in those injured in metropolitan areas of NSW between 2009 and 2014. The apparent downward trend in mortality associated with severe trauma in rural/regional locations requires further analysis.

Trends and characteristics of short-term and frequent representations to emergency departments: A population-based study from New South Wales, Australia.

OBJECTIVE: The objective of this study is to describe the trends and characteristics of short-term and frequent representations to EDs in New South Wales, Australia. METHODS: This was a retrospective analysis of a linked population-based registry of ED representations in New South Wales, conducted as part of the Demand for Emergency Services in Years 2010-2014 project. Trend analysis of unplanned representations to ED within 3 days of discharge from ED, readmission to an in-patient unit within 30 days of index in-patient admission from ED and demographic data and trends for frequent and very frequent ED presenters is discussed. RESULTS: A total of 10 798 797 ED presentations were identified from 4 188 283 individual patients. Within 1 year, 48.9% of ED presentations had a previous presentation, and 4.9% had represented within 3 days of a previous presentation. The readmission rate within 30 days was 2.8%, the proportion of frequent (representing 5212 [0.1%] individual patients) and very frequent representations (representing 1186 [0.03%] individual patients) were 1.7% and 1.0%, respectively. The overall rate of representations within 3 days has decreased from 5.1% in 2010 to 4.7% in 2014 (P < 0.001). The rate of readmissions within 30 days has increased from 2.4% in 2010 to 3.1% in 2014 (P < 0.001). CONCLUSIONS: In this population-based study, short-term representations were highest in the infant patient population, in-patient readmission rates were highest in the elderly and very frequent representations to ED were characterised by middle-aged patients with mental health or drug and alcohol related presentations.

Statewide retrospective study of low acuity emergency presentations in New South Wales, Australia: who, what, where and why?

OBJECTIVE: The present study aims to use a statewide population-based registry to assess the prevalence of low acuity emergency department (ED) presentations, describe the trend in presentation rates and to determine whether they were associated with various presentation characteristics such as the type of hospital as well as clinical and demographic variables. DESIGN AND SETTING: This was a retrospective analysis of a population-based registry of ED presentations in New South Wales (NSW). Generalised estimating equations with log links were used to determine factors associated with low acuity presentations to account for repeat presentations and the possibility of clustering of outcomes. PARTICIPANTS: Patients were included in this analysis if they presented to an ED between January 2010 and December 2014. The outcomes of interest were low acuity presentation, defined as those who self-presented (were not transported by ambulance), were assigned a triage category of 4 or 5 (semiurgent or non-urgent) and discharged back to usual residence from ED. RESULTS: There were 10.7 million ED presentations analysed. Of these, 45% were classified as a low acuity presentation. There was no discernible increase in the rate of low acuity presentations across NSW between 2010 and 2014. The strongest predictors of low acuity ED presentation were age <40 years of age (OR 1.77); injury or musculoskeletal administrative and non-urgent procedures (OR 2.96); ear, nose and throat, eye or oral (OR 5.53); skin or allergy-type presenting problems (OR 2.84). CONCLUSIONS: Low acuity ED presentations comprise almost half of all ED presentations. Alternative emergency models of care may help meet the needs of these patients.

Demand for Emergency Services Trends in New South Wales Years 2010-2014 (DESTINY): Age and Clinical Factors Associated with Ambulance Transportation to Emergency Departments.

OBJECTIVES: The study aimed to analyze ambulance transportations to Emergency Departments (EDs) in New South Wales (NSW) and to identify temporal changes in demographics, acuity, and clinical diagnoses. METHODS: This was a retrospective analysis of a population based registry of ED presentations in New South Wales. The NSW Emergency Department data collection (EDCC) collects patient level data on presentations to designated EDs across NSW. Patients that presented to EDs by ambulance between January 2010 and December 2014 were included. Patients dead on arrival, transferred from another hospital, or planned ED presentations were excluded. RESULTS: A total of 10.8 million ED attendances were identified of which 2.6 million (23%) were transported to ED by ambulance. The crude rate of ambulance transportations to EDs across all ages increased by 3.0% per annum over the five years with the highest rate observed in those 85 years and over (620.5 presentations per 1,000 population). There was an increase in the proportion of category 1 and 2 (life-threatening or potentially life-threatening) cases from 18.1% to 24.0%. CONCLUSION: Demand for ambulance services appears to be driven by older patients presenting with higher acuity problems. Alternative models of acute care for elderly patients need to be planned and implemented to address these changes.