Mode of arrival to the emergency department - a national, cross-sectional study in Sweden

Background: Swedish Emergency Departments (EDs) see 2.6 million visits annually. Sweden has a strong tradition of health care databases, but mode of arrival to the ED is not documented in any registry. The situation is similar in most of Europe. The aim of the study was to provide a national overview of the mode of arrival, medical acuity according to triage, chief complaints, and hospital admission rates for adult patients ( ≥ 18 years) visiting Swedish EDs during 24h. Methods: A national cross-sectional study including all patients at 43 of Sweden’s 72 EDs during 24 hours on April 25 th , 2018. Mode of arrival, medical acuity at triage, admission and basic demographics were registered by dedicated assessors present at every ED for the duration of the study. Descriptive data are reported. Results: A total of 3875 adult patients (median age 59; range 18 to 107; 50% men) were included in the study. Complete data for mode of arrival was reported for 3693 patients (98%). The most common mode of arrival was self-referred walk-in (n=1310; 34%), followed by ambulance (n=920; 24%), referral from a general practitioner (n=497; 13%), and telephone triage referral by the national healthcare guide service “Healthcare Guide 1177” (n=409; 10%). In patients 18 to 64 years, self-referred walk-in was most common, whereas transport by ambulance dominated in patients >64 years. Of the 3365 patients that received an acuity level at triage, 4% were classied as Red (Immediate), 18% as Orange (very urgent), 47% as Yellow (Urgent), 26% as Green (Standard), and 5% as Blue (Non-Urgent). Patients presented with very diverse complaints but about a quarter had abdominal or chest pain. Overall, the admission rate was 27%. Arrival by ambulance was associated with the highest rate of admission (486 of 920; 53%), self-referred walk-in and telephone triage referrals were less often admitted. Conclusion: Self-referred walk-in was the overall most common mode of arrival followed by ambulance.

The quality of emergency care is an area of increasing interest both in Sweden and elsewhere. Sweden has a tradition of comprehensive healthcare quality registries but the National Quality Registry for EDs (2) has little governmental support and the coverage is as of yet approximately 40%. Hence, national data on ED health care delivery, such as mode of arrival, is lacking.
There are only a few single-centre studies on the mode of ED arrival in Sweden. The most recent study indicated that ambulance was the most common mode of arrival followed by referrals or recommendations from various telephone-based healthcare services, such as the national service "Healthcare Guide 1177" or primary care telephone services (3). Other single-centre studies con rm that many patients are referred to the ED from a previous encounter with healthcare (3,4). As in other highincome countries, there is an ongoing debate in Sweden concerning the appropriate use of emergency care, speci cally focusing on self-referred walk-in and low-acuity patients in EDs (5). To date, however, this debate is largely uninformed since the national panorama of ED arrivals and their associated medical acuity remains unknown.
Thus, the aim of this study was to provide a national overview of the mode of arrival, medical acuity according to triage, chief complaints and hospital admission rates for adult patients visiting Swedish EDs during 24h.

Methods
This was a national, cross sectional study including all adult (18 years or above) patients attending Swedish EDs during 24 hours on April 25th, 2018.
The study was approved by the regional ethics review board in Linköping (permit number 2018/50 − 31).
Patients were informed about the study by posters in the waiting rooms in all participating EDs, and consent was presumed unless patients actively declined participation.
Participating sites were recruited in a two-step process: All Swedish EDs were initially contacted by an email to the head of the department, followed by a telephone call. Participation was con rmed in writing by the head of department. Each participating ED was instructed to appoint a local study coordinator who was responsible for the study at the site.

Acuity Assessment
Most EDs in Sweden use the RETTS system (6) to classify patients to one of ve triage levels -blue, green, yellow, orange or red re ecting the planned acceptable waiting time to assessment by a doctor. Blue indicates a limited need of emergency care and red an immediately life-threatening condition. The reported RETTS classi cations were used as indicators of medical acuity.

Data collection
Data collection was divided into an initial phase and a secondary phase. In the initial phase, each ED lled in a form (Appendix 1) to register mode of arrival and information on each adult arriving to the ED during the 24-hour study period. The patients were asked by the front desk personnel about prior contacts with any healthcare provider relating to the present chief complaint. Data collection was supervised by the local coordinators based on instructions from the central study coordinator. Typically, the initial patient registration was performed either by dedicated personnel at the front desk or by the ED nurse receiving the ambulance for patients arriving by ambulance. Standardized training was provided in video-format and supplemented by written instructions.
Data acquisition concerning medical acuity according to RETTS, chief complaints, admission to inhospital care and data losses was performed in the secondary phase of data collection, after the initial 24-hour study period.
All data was compiled in a spreadsheet by the local coordinator at each ED and delivered to the central study coordinator.

De nitions
In the present study, mode of arrival was broadly de ned as the most recent, previous healthcare encounter or physical pathway leading up to the ED visit. Self-referred patients without prior healthcare contacts before presentation to the ED were registered as walk-in arrivals. Other patients were assigned one of the following categories: (referral from) Healthcare Guide 1177; general practitioner with referral; general practitioner without referral; other in-hospital doctor with referral; other in-hospital doctor without referral; internet medical service with referral; internet medical service without referral; referred by other healthcare provider; return visit (scheduled); arrival by ambulance. Only one alternative was allowed for each patient. Patients arriving by ambulance were not asked about previous contacts, since only the most proximal events leading to the ED visit was considered in this study.

Data analysis
The number of patients with the different modes of ED arrival was counted and divided by the total number of patients to gain the percentage distribution. A similar procedure was used to calculate percentage distribution of different modes of arrival for each ED that participated in the study.
The total number of patients per reported medical acuity level was calculated and divided by the total number of patients, as well as for each ED respectively, and presented as a percentage distribution. For the assessment of medical acuity patients classi ed as Orange and Red according to RETTS were considered as one group named Critical illness.
The percentage distribution for the in-hospital admission rate for respective mode of arrival was calculated by adding up all admitted patients per mode of arrival and dividing that by the total number for each mode of arrival, respectively.

Results
Of the invited 72 EDs, 55 agreed to participate, 11 declined and six never responded. Two EDs left the study before submitting data (Fig. 1). Forty-three of the remaining EDs (60%) submitted data for analysis, see Appendix 2. In total, 3875 adult patients were included, median 59 years of age; range 18 to 107 years; 50% men. The number of complete data for the different variables is presented in Table 1.  Figure 2 shows that the most common mode of arrival was self-referred walk-in (34%), followed by arrival by ambulance (24%), referral from a general practitioner (13%), and referral from Healthcare Guide 1177 (10%).
Self-referred Walk-in was also the most common mode of arrival for patients aged 18 to 29 years (271 of 596; 45%) and 30 to 64 years (614 of 1638; 37%). Arrival by ambulance was the most common mode of arrival for patients between 65 and 80 years (341 of 1081; 32%) and for those 81 years and older (294 of 569; 52%) ( Fig. 3).
Of the 3875 included patients, were 3365 (87%) triaged according to RETTS (remaining patients were either incorrectly triaged using acuity levels not included in the RETTS system or lacked acuity level). Of these, 4% were triaged as Red, 18% as Orange, 47% as Yellow, 26% as Green and 5% as Blue.
Three hundred eighty six of the 920 patients arriving by ambulance (42%) were triaged as critically ill (RETTS Red or Orange), and 180 of the 1310 self-referred walk-in patients (14%) ( Table 2).  Table 3 shows that the most common chief complaint at ED presentation was abdominal pain (524; 14%), followed by chest pain (369; 10%) and breathing problems (278; 7%). Table 3 The 20 most common chief complaints as reported by the patients upon presentation to a ED, categorized in accordance with the triage system (RETTS). The Average column shows the total number and proportion of patients with a speci c chief complaint in relation to the total number of patients in the study (3875 The overall hospital admission rate for the entire cohort was 27% (1056 patients). Arrival by ambulance was associated with the highest rate of hospital admission at 53% (486 of 920), followed by self-referred walk-in at 17% (222 of 1310), see Table 4. The admission rate for those triaged as critically ill was 59% (446 of 755), and it was 26% (405 of 1574) for the Yellow, 13% (112 of 884) for the Green, and 2% (4 of161) for the Blue patient groups, respectively.

Discussion
This is the rst nationwide study in Sweden describing mode of ED arrival, as well as the associated medical acuity, chief complaints, and hospital admissions rates for adult patients. The most common mode of arrival was self-referred walk-in which corresponded to approximately one third of all ED arrivals. A large proportion of the self-referred walk-ins were young and had less urgent medical needs, as indicated by low triage levels and admission rates. In contrast, patients arriving by ambulance were often elderly, critically ill, and were often admitted to in-hospital care.
The present results also show that a common mode of arrival is referral to the ED by the national healthcare guide service, Healthcare Guide 1177 (11%). For these patients, critical illness or need for hospital admission were rare. Similar patterns have been reported in previous studies (7-10) which leads to the question whether some of these patients could be managed elsewhere in the healthcare system, and thereby decrease the strain on the EDs. This is an important issue, since crowding leads to an increased ED workload and longer waiting times, potentially affecting the quality of care especially for patients with time-sensitive conditions (8, 11).
Limited availability of primary care may partly explain why so many low acuity patients come to the ED, since primary care in Sweden mostly operates during o ce hours, and usually requires an appointment (11)(12)(13). In addition, some patients may believe they will receive better care at the hospital ED or overestimate the urgency of their health issue (9,10). Another factor is that emergency medicine is under development as a medical specialty in Sweden, and other specialities may sometimes still consider the ED as convenient venue for the management of semi-urgent outpatients. Hence there are several explanations to why the proportion of low acuity patients is large.
Further, the current study highlights large differences in modes of arrival between hospitals. This may partly be explained by geographical differences in the organization of acute care since, in some parts of the country, the ED may be the only healthcare available outside of o ce hours, and an ambulance may be the only available means of transportation for e.g., the elderly. However, geography cannot explain the large variation of low acuity patients arriving by self-referred walk-in, or those who have been in previous contact with primary care. Rather, our results indicate that there may be differences in the decisionmaking process leading up to ED referrals, and point to a need for clear criteria for ED care.
The ndings of the current study underscore the need for continuous reporting of mode of arrival, as well as other basic information on ED patients on a national level. In contrast to Sweden and most other European countries, Australia has a well-developed system for continuously reporting mode of arrival for all ED patients (7) and we strongly suggest that such a model for national reporting be implemented in Europe as well. Such information would provide a better understanding of ED operations and allow us to optimize resource use and continuously monitor outcomes within emergency healthcare.

Limitations
There are some methodological limitations to this study. The initial triage classi cation and admission rate are rather blunt instruments for estimating medical acuity but are commonly used. Information about previous health care contacts was reported by patients and manually recorded with no means of quality control. Although two thirds of all EDs in Sweden participated, several EDs in the major cities (3 in Stockholm and 2 in Gothenburg) declined participation. However, the participating EDs are geographically evenly distributed in Sweden and include EDs of all sizes, and we therefore believe that the results are generalizable. It is a limitation that the study results are point estimates from one 24-hour period. However, the speci c date was chosen to represent a day in the middle of the week and not during a holiday period to make it representative of regular ED operations.

Conclusion
Self-referred walk-in, arrival by ambulance and referral from primary care, either after a physical or telephone contact, were the predominating modes of arrival at Swedish EDs. Declarations Ethics approval: The study was approved by the regional ethics review board in Linköping (permit number 2018/50-31). Patients were informed about the study by posters in the waiting rooms in all participating EDs, and consent was presumed unless patients actively declined participation.

Consent for publication: Not applicable
Availability of data and materials: The dataset used and analysed during the current study are available from the corresponding author on reasonable request.
Competing interests: The authors declare that they have no competing interests.
Funding: This work was supported by two grants from Region Östergötland to author DBW (LIO-532001 and LIO-700271).
Author UE is part of the AIR Lund (Arti cially Intelligent use of Registers at Lund University) research environment and received funding from the Swedish Research Council (VR; grant no. 2019-00198).
The funding bodies had no role or in uence over any aspect of this study. Open access funding was provided by Linköping University.
Author's contributions: DBW, LK, UE and BZ conceived the study. DBW obtained the necessary permits. DBW and UE obtained funding. DBW, JH and JHa coordinated data collection. JH, JHa and DBW analyzed the data and drafted the manuscript. All authors discussed the results and commented on the manuscript.

Figure 1
Schematic of the recruitment process, data acquisition processes and number of participating emergency departments (EDs) in the study. Figure 2