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Public Health & Policy | Epidemiology

Epidemiological trends in emergency department visits by age group: a report from the National Emergency Department Information System (NEDIS) of Korea, 2020–2024

Hang A Park1,*orcid, Taehui Kim2,*orcid, Hyo Jin Kim2orcid, So-hyun Han2orcid
Clinical and Experimental Emergency Medicine 2025;12(4):405-413.
Published online: December 17, 2025

1Department of Emergency Medicine, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea

2National Emergency Medical Center, National Medical Center, Seoul, Korea

Correspondenc to: So-hyun Han National Emergency Medical Center, National Medical Center, 245 Eulji-ro, Jung-gu, Seoul 04564, Korea Email: peacehoi@nmc.or.kr

Hang A Park and Taehui Kim contributed equally to this study as co-first authors.

• Received: November 29, 2025   • Accepted: December 3, 2025

Copyright © 2025 The Korean Society of Emergency Medicine

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/).

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Emergency departments (EDs) provide essential acute and non-routine care and serve as a safety net for populations with diverse medical needs. Monitoring trends in ED visits and outcomes is important for evidence-based emergency care policy development and for understanding how health systems respond to demographic, epidemiologic, and policy changes [1–3].
Over the past decade, many countries have experienced increased ED volumes, greater clinical complexity, and evolving admission practices [3]. These shifts were further intensified during the COVID-19 pandemic, which challenged healthcare system capacity, resource allocation, and the timeliness of emergency care [4].
Trends in post-ED outcomes, such as hospitalizations, transfers, and mortality, offer important insights into emergency care system performance [5]. Understanding these longitudinal patterns helps identify shifts in patient demand and supports data-driven policy decisions. Therefore, by extending prior National Emergency Department Information System (NEDIS) analyses to include the later phase of the COVID-19 pandemic and the 2024 medical crisis in Korea, this report provides updated national data on ED utilization and outcomes across adults, children, and older adults, including those with severe illness diagnosis codes (SIDC).
Ethics statement
This study was approved by the Institutional Review Board of the National Medical Center (No. NMC-2023-08-094). The requirement for informed consent was waived due to the retrospective, observational, and anonymous nature of the study. All methods were performed in accordance with the relevant ethical guidelines and regulations.
Data sources and study population
The study was conducted using data from the NEDIS, a mandatory nationwide database that collects standardized administrative and clinical information from all designated emergency medical institutions in Korea [6]. Data are automatically transferred to a central server and monitored by coordinators at the National Emergency Medical Center (NEMC) [7]. Participating EDs are classified into level I (regional emergency medical and trauma centers), level II (local emergency medical centers), and level III (local emergency medical agencies) [8].
All ED visits recorded in NEDIS from January 1, 2020, to December 31, 2024, were analyzed using methods consistent with a previous study (2018–2022) [5]. Variables included demographics and prehospital and hospital information, such as age, sex, insurance type, visit characteristics, Korean Triage and Acuity Scale (KTAS) score, chief complaint, and primary and discharge diagnoses (Korean Standard Classification of Diseases [KCD], 8th Revision), as well as ED and hospital outcomes.
Statistical analysis
Descriptive analyses summarized annual ED visit counts, patient demographics, clinical characteristics, and outcomes. Age- and sex-standardized ED visit rates per 100,000 population were calculated using direct standardization with the 2020 Korean mid-year census. Standardized mortality, admission, and transfer rates were computed as weighted averages of age- and sex-specific rates within the ED population. Five-year trends were evaluated using linear regression analysis, and comparisons between 2023 and 2024 were performed using the Z-test.
Critical illness outcomes were examined using the 28 predefined SIDC categories established by the Korean Ministry of Health and Welfare [5]. Additional high-risk conditions were defined using expanded criteria: sepsis included standard sepsis codes or infection-related diagnoses accompanied by intensive care unit (ICU) admission or ED death, and cardiac arrest included either a cardiac arrest diagnosis code or documented cardiopulmonary resuscitation in the ED. Operational definitions for all categories are detailed in Supplementary Table 1.
Patient demographics, visit characteristics, and outcomes
A total of 37,098,865 ED visits were recorded during the study period (Table 1). Of these, 21.3 million (57.4%) were adults aged 18–64 years, 5.5 million (14.8%) were pediatric patients aged <18 years, and 10.3 million (27.7%) were older adults aged ≥65 years. The mean patient age was 46.9±24.8 years, and the median time from symptom onset to ED arrival was 290 minutes (interquartile range [IQR], 62–1,440 minutes), with the longest delays observed in older adults (median, 430 minutes; IQR, 92–2,782 minutes). Overall, 20.7% of ED visits occurred at level I centers. Disease-related presentations accounted for 72.3% of ED visits, whereas injuries accounted for 26.5%. Unintentional injuries comprised 58.1% of all injuries and were most frequent among pediatric patients (70.8%). Most patients arrived directly (90.9%), and 20.3% used the 119 ambulance service, with higher use among older adults (33.2%) compared with pediatric patients (8.5%). At initial triage, 53.4% were classified as KTAS 4–5, whereas only 5.9% were KTAS 1–2. SIDC cases accounted for 11.4% of all visits, occurring predominantly in older adults (22.0%) and least often in pediatric patients (3.3%). The mean ED length of stay was 2.8±9.8 hours, and 0.9% of patients remained in the ED for ≥24 hours. Older adults tended to stay longer (4.3±11.3 hours; ≥24 hours, 1.9%) than adults and pediatric patients. Regarding ED disposition, 77.3% of patients were discharged, 20.0% were admitted (16.9% to general wards and 3.1% to ICUs), and 0.7% died in the ED. Admission rates were highest among older adults (36.8%), whereas pediatric patients were more often discharged (90.2%). Overall in-hospital mortality was 1.7% (adults, 0.8%; pediatric patients, 0.1%; older adults, 4.7%).
Common chief complaints and diagnoses
Table 2 presents the 15 most common chief complaints and primary diagnoses overall and by age group. Abdominal pain was the most frequent chief complaint (8.8%), followed by fever (7.9%), dizziness (4.1%), and headache (4.0%). The most frequent diagnosis was acute gastroenteritis (A099), accounting for 4.8% of all ED diagnoses. U071 coronavirus disease (COVID-19, virus identified) emerged among the top 15 diagnoses during the study period.
In pediatric patients, fever (23.9%) was the most common chief complaint, followed by abdominal pain (9.7%) and vomiting (4.2%). In older adults, abdominal pain (7.8%), dyspnea (7.3%), and dizziness (6.6%) were common, and lightheadedness (R42, 4.3%) and pneumonia (J189, 2.8%) appeared among the most frequent diagnoses.
Annual changes in ED visits and ED outcomes
Standardized ED visits per 100,000 population increased from 15,562 in 2020 to 20,322 in 2023; however, they declined by 18.6% in 2024 compared with 2023 (P<0.001) (Table 3). By age group, standardized ED visits per 100,000 population decreased in 2024 compared with 2023 by 20.8% in adults, 11.0% in older adults, and 32.7% in pediatric patients (P<0.001). The 5-year linear trend was not statistically significant for the total population, any age group, or either sex.
Age- and sex-standardized hospital admission rates showed no significant linear trends; however, admission rates increased significantly across all age groups in 2024 compared with 2023 (Fig. 1). Age- and sex-standardized transfer rates declined consistently across adults, older adults, and pediatric patients, with statistically significant trends (P<0.05 in all age groups). Age- and sex-standardized in-hospital mortality rates showed no significant linear trend over the 5-year period. Rates were lowest in 2023, when the impact of the COVID-19 pandemic had largely waned, but increased significantly in 2024 compared with 2023 despite the decline in ED visits (P<0.001).
Burden and outcomes of SIDC
Table 4 summarizes ED visit volumes and outcomes for the 28 SIDC conditions, as well as traumatic brain injury, suicide attempt or self-harm, and COVID-19. COVID-19 was the most common category (24.5 visits per 1,000 ED visits), followed by sepsis using the expanded definition (18.9 per 1,000 ED visits), severe trauma (15.1 per 1,000 ED visits), ischemic stroke (14.7 per 1,000 ED visits), gastrointestinal bleeding or foreign body (11.5 per 1,000 ED visits), arrhythmia (10.9 per 1,000 ED visits), and acute kidney injury (10.9 per 1,000 ED visits). Among these high-volume categories, sepsis (expanded definition) and acute kidney injury had in-hospital mortality rates exceeding 10% (22.2% and 17.2%, respectively). Other disease groups with in-hospital mortality >10% included intracranial hemorrhage (14.5%), subdural hemorrhage (16.7%), aortic dissection (14.4%), severe burn (11.0%), acute respiratory distress syndrome/pulmonary edema (20.9%), disseminated intravascular coagulation (46.7%), and cardiac arrest (77.6%). Among time-dependent illnesses, myocardial infarction had an in-hospital mortality rate of 9.4%, and ischemic stroke had a mortality rate of 5.0%.
This analysis presents 5-year nationwide data on ED utilization and outcomes across pediatric, adult, and older adult populations in Korea using the NEDIS database. Previous reports showed a decline in ED visits early in the COVID-19 pandemic, whereas admission, transfer, and mortality rates remained relatively stable [5]. In contrast, the present analysis demonstrates a gradual recovery in ED visit rates throughout the pandemic period, consistent with findings from other studies [4]. However, the decline in ED visits observed in 2024 appears to reflect changes in healthcare-seeking behavior or ED access restrictions during the 2024–2025 medical crisis in Korea [9,10]. The prolonged disruption of health services may have limited timely access to emergency care, leading some patients to delay care or shift toward primary care settings [10,11]. Despite the reduction in ED volume, in-hospital mortality increased in 2024, suggesting that a larger proportion of patients presenting to the ED during this period were severely ill, as reported in a previous study [11]. However, given that earlier studies have found minimal effects of strike actions on in-hospital mortality, and considering the large sample size and the absence of detailed adjustments in this analysis, the observed increase in 2024 should be interpreted cautiously [12,13]. This rise may partly reflect the substantial reduction in ED visits, particularly among less severe patients during that period, although the underlying reasons for the increased mortality require further investigation. In addition, this analysis showed a decline in transfer rates over the study period; however, the reasons for this pattern are unclear and may involve multiple contributing factors. Further investigation is needed to clarify the underlying causes. Continued monitoring of national ED trends is essential for ensuring timely and effective emergency care, not only during future public health emergencies such as infectious disease outbreaks, but also in responding to ongoing changes in population demographics, disease burden, and healthcare system dynamics.

Author contributions

Conceptualization: all authors; Data curation: TK, HJK; Methodology: all authors; Project administration: SH; Visualization: HAP, TK; Writing–original draft: HAP, TK; Writing–review & editing: all authors. All authors read and approved the final manuscript.

Conflicts of interest

The authors have no conflicts of interest to declare.

Funding

The authors received no financial support for this study.

Data availability

Data from this study were obtained from the National Emergency Medical Center (NEMC) under the Korean Ministry of Health and Welfare, and were used under license for the current study. Although the data are not publicly accessible, they are available from the corresponding author upon reasonable request with permission from the NEMC.

Supplementary Table 1.

Diagnosis codes and definitions for data extraction including 28 severe illness
ceem-25-291-Supplementary-Table-1.pdf
Supplementary materials are available from https://doi.org/10.15441/ceem.25.291.
Fig. 1.
Age- and sex-standardized data by year. (A) Hospital admissions. (B) Transfer rates. (C) In-hospital mortality rates. *P<0.05 (statistically significant differences between 2023 and 2024).
ceem-25-291f1.jpg
Table 1.
Patient demographics, ED visit characteristics, and outcome by age group
Table 1.
Variable Total (n=37,098,865) Age groupa)
Adults (18–64 yr) (n=21,305,650) Pediatric patients (<18 yr) (n=5,501,234) Older adults (≥65 yr) (n=10,291,711)
Age (yr) 46.9±24.8 42.8±13.7 7.2±5.4 76.6±7.8
 0–1 405,175 (1.1) 405,175 (7.4)
 1–6 2,456,213 (6.6) 2,456,213 (44.6)
 7–12 1,419,031 (3.8) 1,419,031 (25.8)
 13–17 1,220,815 (3.3) 1,220,815 (22.2)
 18–40 9,268,739 (25.0) 9,268,739 (43.5)
 41–64 12,036,911 (32.4) 12,036,911 (56.5)
 65–74 4,509,591 (12.2) 4,509,591 (43.8)
 75–84 3,954,033 (10.7) 3,954,033 (38.4)
 85–130 1,828,087 (4.9) 1,828,087 (17.8)
 Unknown 270 (0.0)
Sex
 Male 18,653,101 (50.3) 10,626,641 (49.9) 3,127,825 (56.9) 4,898,480 (47.6)
 Female 18,445,764 (49.7) 10,679,009 (50.1) 2,373,409 (43.1) 5,393,231 (52.4)
Time from the symptom onset to ED arrivalb)
 No. of patients 24,301,333 13,298,057 4,001,763 7,001,485
 Median (IQR) (min) 290 (62–1,440) 246 (60–1,341) 240 (60–1,224) 430 (92–2,782)
Visit day
 Weekday 21,699,904 (58.5) 12,125,872 (56.9) 3,028,348 (55.0) 6,545,534 (63.6)
 Weekend or holiday 15,398,961 (41.5) 9,179,778 (43.1) 2,472,886 (45.0) 3,746,177 (36.4)
Visit time
 08:00–16:00 13,840,820 (37.3) 7,173,397 (33.7) 1,499,496 (27.3) 5,167,806 (50.2)
 16:00–24:00 16,258,209 (43.8) 9,536,775 (44.8) 3,055,231 (55.5) 3,666,088 (35.6)
 24:00–08:00 6,999,836 (18.9) 4,595,478 (21.6) 946,507 (17.2) 1,457,817 (14.2)
Type of ED
 Level I 7,679,592 (20.7) 3,862,042 (18.1) 1,436,792 (26.1) 2,380,745 (23.1)
 Level II 16,931,322 (45.6) 9,643,124 (45.3) 2,590,383 (47.1) 4,697,782 (45.6)
 Level III 12,487,951 (33.7) 7,800,484 (36.6) 1,474,059 (26.8) 3,213,184 (31.2)
Disease categoryb)
 Disease 26,821,758 (72.3) 15,053,977 (70.7) 3,643,168 (66.2) 8,124,482 (78.9)
 Injury 9,834,738 (26.5) 6,006,541 (28.2) 1,818,233 (33.1) 2,009,878 (19.5)
 Dead on arrival 77,004 (0.2) 21,461 (0.1) 479 (0.0) 55,059 (0.5)
 Other or unknown 365,365 (1.0) 223,671 (1.0) 39,354 (0.7) 102,292 (1.0)
Intentionalityb) 9,834,738 (100) 6,006,541 (100) 1,818,233 (100) 2,009,878 (100)
 Accident 5,713,123 (58.1) 3,266,460 (54.4) 1,286,562 (70.8) 1,160,094 (57.7)
 Suicidal 176,345 (1.8) 138,006 (2.3) 17,376 (1.0) 20,962 (1.0)
 Violence 168,204 (1.7) 137,662 (2.3) 16,354 (0.9) 14,187 (0.7)
 Other 154,695 (1.6) 121,129 (2.0) 13,613 (0.7) 19,953 (1.0)
 Unknown 3,622,371 (36.8) 2,343,284 (39.0) 484,328 (26.6) 794,682 (39.5)
Insurance type
 National health insurance 32,686,548 (88.1) 18,600,780 (87.3) 5,231,604 (95.1) 8,854,094 (86.0)
 Automobile insurance 1,096,922 (3.0) 814,934 (3.8) 80,074 (1.5) 201,911 (2.0)
 Occupational health and safety insurance 108,774 (0.3) 94,770 (0.4) 124 (0.0) 13,868 (0.1)
 Private insurance 2,774 (0.0) 2,133 (0.0) 142 (0.0) 499 (0.0)
 Medical aid type 1 1,987,662 (5.4) 888,746 (4.2) 73,877 (1.3) 1,025,021 (10.0)
 Medical aid type 2 337,566 (0.9) 259,560 (1.2) 57,906 (1.1) 20,100 (0.2)
 General insurance 596,661 (1.6) 456,905 (2.1) 36,965 (0.7) 102,658 (1.0)
 Other 185,924 (0.5) 133,198 (0.6) 10,508 (0.2) 42,200 (0.4)
 Unknown 96,034 (0.3) 54,624 (0.3) 10,034 (0.2) 31,360 (0.3)
Route of arrival
 Direct visit 33,704,570 (90.9) 19,834,372 (93.1) 5,126,142 (93.2) 8,743,841 (85.0)
 Transfer from other hospital 2,786,344 (7.5) 1,197,493 (5.6) 325,863 (5.9) 1,262,981 (12.3)
 Referred from outpatient clinics 561,269 (1.5) 246,002 (1.2) 43,356 (0.8) 271,909 (2.6)
 Other 13,642 (0.0) 7,240 (0.0) 1,840 (0.0) 4,561 (0.0)
 Unknown 33,040 (0.1) 20,543 (0.1) 4,033 (0.1) 8,419 (0.1)
Transport
 119 Ambulance 7,540,276 (20.3) 3,653,827 (17.1) 468,942 (8.5) 3,417,462 (33.2)
 Other medical institution ambulance 234,759 (0.6) 83,574 (0.4) 6,638 (0.1) 144,542 (1.4)
 Other ambulance 962,218 (2.6) 318,770 (1.5) 24,056 (0.4) 619,384 (6.0)
 Police or official transport 40,390 (0.1) 35,135 (0.2) 1,361 (0.0) 3,892 (0.0)
 Air transport 22,516 (0.1) 13,856 (0.1) 2,063 (0.0) 6,597 (0.1)
 Other transport 27,570,000 (74.3) 16,740,000 (78.6) 4,895,705 (89.0) 5,936,108 (57.7)
 Walk-in 632,413 (1.7) 413,509 (1.9) 93,463 (1.7) 125,432 (1.2)
 Other 58,881 (0.2) 24,398 (0.1) 4,810 (0.1) 29,673 (0.3)
 Unknown 33,974 (0.1) 21,111 (0.1) 4,196 (0.1) 8,621 (0.1)
Initial triage (KTAS score)b)
 1 433,313 (1.2) 142,187 (0.7) 13,775 (0.3) 277,324 (2.7)
 2 1,768,107 (4.8) 750,860 (3.5) 148,111 (2.7) 869,113 (8.4)
 3 13,891,416 (37.4) 7,224,035 (33.9) 1,935,311 (35.2) 4,732,014 (46.0)
 4–5 19,827,228 (53.4) 12,465,924 (58.5) 3,265,397 (59.4) 4,095,783 (39.8)
 Other/unknown 1,178,801 (3.2) 722,644 (3.4) 138,640 (2.5) 317,477 (3.1)
Severe illness diagnosisc) 4,212,883 (11.4) 1,765,999 (8.3) 182,292 (3.3) 2,264,557 (22.0)
Length of stayd)
 Mean±SD (hr) 2.8 ± 9.8 2.4 ± 8.9 1.9 ± 9.9 4.3 ± 11.3
 Median (IQR) (hr) 1.7 (0.7–3.1) 1.5 (0.6–2.7) 1.1 (0.4–2.4) 2.5 (1.3–4.6)
 0–6 hr 33,529,765 (90.4) 19,799,501 (92.9) 5,247,371 (95.4) 8,482,680 (82.4)
 6–12 hr 2,302,211 (6.2) 981,546 (4.6) 191,904 (3.5) 1,128,754 (11.0)
 12–24 hr 883,020 (2.4) 365,174 (1.7) 47,259 (0.9) 470,585 (4.6)
 ≥24 hr 322,786 (0.9) 121,986 (0.6) 6,902 (0.1) 193,898 (1.9)
 Unknown 61,083 (0.2) 37,443 (0.2) 7,798 (0.1) 15,794 (0.2)
ED disposition
 Discharge 28,664,776 (77.3) 17,735,758 (83.2) 4,961,195 (90.2) 5,967,668 (58.0)
 Admissione) 7,428,617 (20.0) 3,148,829 (14.8) 496,811 (9.0) 3,782,930 (36.8)
  General ward 6,255,742 (16.9) 2,717,747 (12.8) 468,081 (8.5) 3,069,880 (29.8)
  Intensive care unit 1,139,056 (3.1) 411,771 (1.9) 27,642 (0.5) 699,630 (6.8)
 Transfer 613,224 (1.7) 253,858 (1.2) 24,618 (0.5) 334,737 (3.3)
 Hopeless discharge 2,523 (0.0) 570 (0.0) 48 (0.0) 1,905 (0.0)
 Death 247,944 (0.7) 71,147 (0.3) 2,667 (0.1) 174,120 (1.7)
 Other 90,239 (0.2) 63,810 (0.3) 9,490 (0.2) 16,939 (0.2)
 Unknown 51,542 (0.1) 31,678 (0.2) 6,405 (0.1) 13,412 (0.1)
Hospital disposition
 Discharge 34,875,444 (94.0) 20,536,840 (96.4) 5,441,353 (98.9) 8,897,076 (86.5)
 Transfer 1,272,225 (3.4) 444,129 (2.1) 32,193 (0.6) 795,888 (7.7)
 Hopeless discharge 6,466 (0.0) 1,826 (0.0) 71 (0.0) 4,569 (0.0)
 Death 643,034 (1.7) 159,152 (0.8) 4,109 (0.1) 479,762 (4.7)
 Other 111,287 (0.3) 72,422 (0.3) 10,186 (0.2) 28,679 (0.3)
 Unknown 190,409 (0.5) 91,281 (0.4) 13,322 (0.2) 85,737 (0.8)

Values are presented as number (%), unless otherwise indicated. Percentages may not total 100 due to rounding.

ED, emergency department; KTAS, Korean Triage Acuity Scale; IQR, interquartile range; SD, standard deviation.

a)Patients with missing age information were excluded from the analysis (n=270).

b)Reporting not obligatory for level III EDs (recording KTAS scores became mandatory starting from 2021); hence, there is a higher likelihood of missing data for level III EDs.

c)28 Severe illness diagnosis codes are listed in Supplementary Table 1.

d)Any ED length of stay over 5 days was treated as 5 days.

e)Admission locations include areas other than general wards or intensive care units, including unspecified locations.

Table 2.
Top 15 chief complaints by UMLS code and main diagnosis by KCD code
Table 2.
Rank UMLS code No. of patients (%) KCD code No. of patients (%)
Total (n=37,098,865)
 1 Abdominal pain 3,946,827 (8.8) A099 (gastroenteritis and colitis of unspecified origin) 1,776,048 (4.8)
 2 Fever 3,530,106 (7.9) R1049 (unspecified abdominal pain) 1,054,325 (2.9)
 3 Dizziness 1,853,536 (4.1) R42 (lightheadedness) 1,024,586 (2.8)
 4 Headache 1,795,042 (4.0) R5099 (hyperpyrexia NOS) 927,726 (2.5)
 5 Dyspnea 1,416,604 (3.2) Z115 (special screening examination for other viral disease) 703,181 (1.9)
 6 Vomiting 1,088,639 (2.4) R51 (headache) 617,324 (1.7)
 7 Diarrhea 907,524 (2.0) S610 (open wound of finger(s) without damage to nail) 609,640 (1.7)
 8 Nausea 869,155 (1.9) U071 (coronavirus disease, virus identified [COVID-19, virus identified]) 607,018 (1.6)
 9 Generalized weakness 819,326 (1.8) S0600 (concussion, without open intracranial wound) 574,796 (1.6)
 10 Epigastric pain 805,449 (1.8) L509 (urticaria, unspecified) 457,785 (1.2)
 11 Chest pain 786,829 (1.8) R074 (chest pain, unspecified) 456,768 (1.2)
 12 Cough 766,726 (1.7) N201 (calculus of ureter) 447,421 (1.2)
 13 Sore throat 739,620 (1.7) J189 (pneumonia, unspecified) 425,612 (1.2)
 14 Back pain 704,491 (1.6) J069 (upper respiratory disease, acute) 390,925 (1.1)
 15 Myalgia 638,766 (1.4) T140 (superficial injury of unspecified body region) 338,815 (0.9)
Pediatric patients (<18 yr) (n=5,501,234)
 1 Fever 1,287,825 (23.9) R5099 (hyperpyrexia NOS) 405,286 (7.4)
 2 Abdominal pain 522,431 (9.7) A099 (gastroenteritis and colitis of unspecified origin) 367,155 (6.7)
 3 Vomiting 226,766 (4.2) R1049 (unspecified abdominal pain) 178,629 (3.3)
 4 Headache 137,165 (2.6) S0600 (concussion, without open intracranial wound) 138,802 (2.5)
 5 Cough 125,886 (2.3) B349 (viraemia NOS) 123,296 (2.3)
 6 Skin rash 115,726 (2.2) L509 (urticaria, unspecified) 115,099 (2.1)
 7 Urticaria 100,383 (1.9) J069 (upper respiratory disease, acute) 105,648 (1.9)
 8 Head trauma 82,159 (1.5) S018 (open wound of other parts of head) 104,287 (1.9)
 9 Pain in finger 78,938 (1.5) U071 (coronavirus disease, virus identified [COVID-19, virus identified]) 97,579 (1.8)
 10 Ankle pain 70,816 (1.3) J00 (acute rhinitis) 94,703 (1.7)
 11 Sore throat 66,482 (1.2) J029 (acute bronchitis, unspecified) 81,158 (1.5)
 12 Seizures 61,706 (1.1) J101 (seasonal influenza virus identified influenza with other respiratory manifestations) 76,562 (1.4)
 13 Dyspnea 61,571 (1.1) J111 (influenza with other respiratory manifestations, virus not identified) 71,384 (1.3)
 14 Pain in elbow 60,525 (1.1) T140 (superficial injury of unspecified body region) 64,390 (1.2)
 15 Diarrhea 45,409 (0.8) S010 (open wound of scalp) 63,683 (1.2)
Older adults (≥65 yr) (n=10,291,711)
 1 Abdominal pain 786,086 (7.8) R42 (lightheadedness) 443,418 (4.3)
 2 Dyspnea 735,053 (7.3) J189 (pneumonia, unspecified) 284,860 (2.8)
 3 Dizziness 659,342 (6.6) A099 (gastroenteritis and colitis of unspecified origin) 262,824 (2.6)
 4 Fever 586,141 (5.8) R1049 (unspecified abdominal pain) 216,558 (2.1)
 5 Generalized weakness 442,056 (4.4) U071 (coronavirus disease, virus identified [COVID-19, virus identified]) 202,537 (2.0)
 6 Headache 287,664 (2.9) R5099 (hyperpyrexia NOS) 159,802 (1.6)
 7 Chest pain 250,831 (2.5) I639 (cerebral infarction, unspecified) 152,858 (1.5)
 8 Back pain 198,484 (2.0) R060 (shortness of breath) 146,773 (1.4)
 9 Coxalgia 169,863 (1.7) R074 (chest pain, unspecified) 136,173 (1.3)
 10 Epigastric pain 142,541 (1.4) N390 (urinary tract infection, site not specified) 128,721 (1.3)
 11 Syncope 107,119 (1.1) S0600 (concussion, without open intracranial wound) 125,233 (1.2)
 12 Chest discomfort 101,352 (1.0) R51 (headache) 118,924 (1.2)
 13 Vomiting 97,364 (1.0) R53 (chronic debility) 117,842 (1.2)
 14 Low back pain 96,639 (1.0) Z115 (special screening examination for other viral diseases) 107,380 (1.1)
 15 Diarrhea 96,029 (1.0) K5909 (other and unspecified constipation) 106,371 (1.0)

UMLS, Unified Medical Language System; KCD, Korean Standard Classification of Diseases.

Table 3.
Age- and sex-standardized emergency department visits per 100,000 population (2020–2024)
Table 3.
Sex Year
 P for trend
2020 2021 2022 2023 2024a)
Total 15,562 16,093 17,973 20,322 16,543 0.378
 Male 16,873 17,102 19,150 21,650 17,860 0.362
 Female 14,250 15,084 16,797 18,995 15,226 0.398
Adults (18–64 yr) 11,913 12,147 12,336 13,051 10,341 0.558
 Male 12,071 11,871 11,899 12,450 10,016 0.297
 Female 11,755 12,424 12,772 13,651 10,667 0.830
Pediatric patients (<18 yr) 11,702 11,596 15,144 19,024 12,796 0.406
 Male 12,984 12,845 16,874 21,008 14,215 0.403
 Female 10,419 10,347 13,414 17,040 11,378 0.409
Older adults (≥65 yr) 23,380 25,048 28,684 32,736 29,140 0.085
 Male 26,682 28,096 32,279 36,917 33,231 0.073
 Female 20,078 21,999 25,090 28,554 25,050 0.102

a)All comparisons between 2023 and 2024 showed statistically significant differences.

Table 4.
Summary of ED outcomes for 28 severe illness codes and selected diagnostic categories (including traumatic brain injury, suicide attempt/self-harm, and COVID-19)
Table 4.
Disease category No. of patients No. of patients per 1,000 ED visits ED discharge rate (%) Transfer rate (%) Admission rate (%) ICU admission rate (%) No. of hospital deaths In-hospital mortality (%)
Myocardial infarction 213,538 5.8 4.7 9.2 84.3 55.7 20,012 9.4
Ischemic stroke 546,175 14.7 15.0 4.3 80.4 23.2 27,359 5.0
Intracranial hemorrhage 142,413 3.8 6.3 10.9 81.5 57.4 20,613 14.5
Cardiac arrest (diagnosis code) 165,481 4.5 0.7 5.4 33.3 27.9 130,353 78.8
Cardiac arrest (diagnosis code or cardiopulmonary resuscitation in ED)a) 205,617 5.5 2.9 5.6 26.6 24.1 159,527 77.6
Subdural hemorrhage 53,370 1.4 4.0 16.5 77.4 65.8 8,894 16.7
Severe trauma 559,392 15.1 21.0 7.7 69.6 25.1 29,494 5.3
Sepsis (diagnosis code) 229,397 6.2 5.3 3.3 90.1 37.3 54,413 23.7
Sepsis (extended definition)a),b) 701,157 18.9 1.9 1.6 93.4 72.5 155,928 22.2
Aortic dissection 24,069 0.6 9.0 21.3 64.3 44.8 3,467 14.4
Biliary disease 358,891 9.7 11.7 6.0 82.1 6.5 10,224 2.8
Surgical diagnosis 261,395 7.0 5.8 5.5 88.2 12.3 12,608 4.8
GI bleeding/FB 428,153 11.5 22.4 3.8 72.9 18.5 25,468 5.9
Tracheal bleeding/FB 65,731 1.8 36.0 3.2 59.8 10.5 4,131 6.3
Intoxication 302,148 8.1 71.2 2.4 25.5 12.9 3,652 1.2
Perinatal disease 70,139 1.9 8.7 1.2 90.0 3.2 67 0.1
Premature (low birth weight) 17,465 0.5 15.8 1.4 82.7 61.0 109 0.6
Severe burn 1,312 0.0 17.9 18.5 61.7 33.3 144 11.0
Status epilepticus 24,218 0.7 9.9 4.9 84.9 44.5 1,746 7.2
Meningitis 54,079 1.5 28.9 2.0 68.9 13.5 1,893 3.5
Diabetic encephalopathy 47,813 1.3 9.0 5.9 83.8 45.1 3,977 8.3
Pulmonary embolism/DVT 106,614 2.9 17.2 2.8 79.2 22.2 10,313 9.7
Arrhythmia 403,265 10.9 22.3 2.0 75.2 26.4 31,470 7.8
ARDS/pulmonary edema 207,161 5.6 5.6 3.2 89.8 36.2 43,339 20.9
DIC 14,370 0.4 3.2 0.7 94.2 53.4 6,713 46.7
Intussusception/ileus 95,320 2.6 13.7 4.5 81.5 6.6 3,308 3.5
Amputation 36,441 1.0 23.9 5.2 69.3 30.2 1,241 3.4
Acute kidney injury 404,505 10.9 8.6 3.8 86.7 30.8 69,408 17.2
Ophthalmic emergency 40,811 1.1 55.8 0.4 43.6 3.1 209 0.5
Urologic emergency 19,529 0.5 69.4 1.3 29.2 1.4 69 0.4
TBIa),c) 246,811 6.7 19.5 8.7 70.7 38.8 18,118 7.3
Suicide attempt and self-harma),d) 209,746 5.7 63.4 3.9 29.1 15.5 8,129 3.9
COVID-19a) 907,336 24.5 63.7 2.2 32.8 4.7 28,482 3.1

ED, emergency department; ICU, intensive care unit; GI, gastrointestinal; FB, foreign body; DVT, deep vein thrombosis; ARDS, acute respiratory distress syndrome; DIC, disseminated intravascular coagulation; TBI, traumatic brain injury.

a)In addition to the 28 predefined severe illness codes, several diagnostic codes were additionally selected and included in this table.

b)(Infection diagnosis code AND ICU admission/ED death) OR sepsis/septic shock diagnosis code.

c)Identified based on International Classification of Diseases, 10th Revision (ICD-10) diagnostic codes (S06.1–S06.9) that correspond to the TBI definition established by the Korea Disease Control and Prevention Agency.

d)Any of the following three conditions: (1) the intention of self-harm or suicide; (2) initial severity classification falls into the suicide attempt, suicidal intent, or suicidal ideation categories under the Korean Triage and Acuity Scale (KTAS); or (3) discharge diagnosis codes based on the Korean Standard Classification of Disease (KCD), X60–X84 (excluding X65).

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Epidemiological trends in emergency department visits by age group: a report from the National Emergency Department Information System (NEDIS) of Korea, 2020–2024
Clin Exp Emerg Med. 2025;12(4):405-413.   Published online December 31, 2025
DOI: https://doi.org/10.15441/ceem.25.291
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Epidemiological trends in emergency department visits by age group: a report from the National Emergency Department Information System (NEDIS) of Korea, 2020–2024
Clin Exp Emerg Med. 2025;12(4):405-413.   Published online December 31, 2025
DOI: https://doi.org/10.15441/ceem.25.291
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Epidemiological trends in emergency department visits by age group: a report from the National Emergency Department Information System (NEDIS) of Korea, 2020–2024
Image
Fig. 1. Age- and sex-standardized data by year. (A) Hospital admissions. (B) Transfer rates. (C) In-hospital mortality rates. *P<0.05 (statistically significant differences between 2023 and 2024).

Fig. 1.

Epidemiological trends in emergency department visits by age group: a report from the National Emergency Department Information System (NEDIS) of Korea, 2020–2024
Variable Total (n=37,098,865) Age groupa)
Adults (18–64 yr) (n=21,305,650) Pediatric patients (<18 yr) (n=5,501,234) Older adults (≥65 yr) (n=10,291,711)
Age (yr) 46.9±24.8 42.8±13.7 7.2±5.4 76.6±7.8
 0–1 405,175 (1.1) 405,175 (7.4)
 1–6 2,456,213 (6.6) 2,456,213 (44.6)
 7–12 1,419,031 (3.8) 1,419,031 (25.8)
 13–17 1,220,815 (3.3) 1,220,815 (22.2)
 18–40 9,268,739 (25.0) 9,268,739 (43.5)
 41–64 12,036,911 (32.4) 12,036,911 (56.5)
 65–74 4,509,591 (12.2) 4,509,591 (43.8)
 75–84 3,954,033 (10.7) 3,954,033 (38.4)
 85–130 1,828,087 (4.9) 1,828,087 (17.8)
 Unknown 270 (0.0)
Sex
 Male 18,653,101 (50.3) 10,626,641 (49.9) 3,127,825 (56.9) 4,898,480 (47.6)
 Female 18,445,764 (49.7) 10,679,009 (50.1) 2,373,409 (43.1) 5,393,231 (52.4)
Time from the symptom onset to ED arrivalb)
 No. of patients 24,301,333 13,298,057 4,001,763 7,001,485
 Median (IQR) (min) 290 (62–1,440) 246 (60–1,341) 240 (60–1,224) 430 (92–2,782)
Visit day
 Weekday 21,699,904 (58.5) 12,125,872 (56.9) 3,028,348 (55.0) 6,545,534 (63.6)
 Weekend or holiday 15,398,961 (41.5) 9,179,778 (43.1) 2,472,886 (45.0) 3,746,177 (36.4)
Visit time
 08:00–16:00 13,840,820 (37.3) 7,173,397 (33.7) 1,499,496 (27.3) 5,167,806 (50.2)
 16:00–24:00 16,258,209 (43.8) 9,536,775 (44.8) 3,055,231 (55.5) 3,666,088 (35.6)
 24:00–08:00 6,999,836 (18.9) 4,595,478 (21.6) 946,507 (17.2) 1,457,817 (14.2)
Type of ED
 Level I 7,679,592 (20.7) 3,862,042 (18.1) 1,436,792 (26.1) 2,380,745 (23.1)
 Level II 16,931,322 (45.6) 9,643,124 (45.3) 2,590,383 (47.1) 4,697,782 (45.6)
 Level III 12,487,951 (33.7) 7,800,484 (36.6) 1,474,059 (26.8) 3,213,184 (31.2)
Disease categoryb)
 Disease 26,821,758 (72.3) 15,053,977 (70.7) 3,643,168 (66.2) 8,124,482 (78.9)
 Injury 9,834,738 (26.5) 6,006,541 (28.2) 1,818,233 (33.1) 2,009,878 (19.5)
 Dead on arrival 77,004 (0.2) 21,461 (0.1) 479 (0.0) 55,059 (0.5)
 Other or unknown 365,365 (1.0) 223,671 (1.0) 39,354 (0.7) 102,292 (1.0)
Intentionalityb) 9,834,738 (100) 6,006,541 (100) 1,818,233 (100) 2,009,878 (100)
 Accident 5,713,123 (58.1) 3,266,460 (54.4) 1,286,562 (70.8) 1,160,094 (57.7)
 Suicidal 176,345 (1.8) 138,006 (2.3) 17,376 (1.0) 20,962 (1.0)
 Violence 168,204 (1.7) 137,662 (2.3) 16,354 (0.9) 14,187 (0.7)
 Other 154,695 (1.6) 121,129 (2.0) 13,613 (0.7) 19,953 (1.0)
 Unknown 3,622,371 (36.8) 2,343,284 (39.0) 484,328 (26.6) 794,682 (39.5)
Insurance type
 National health insurance 32,686,548 (88.1) 18,600,780 (87.3) 5,231,604 (95.1) 8,854,094 (86.0)
 Automobile insurance 1,096,922 (3.0) 814,934 (3.8) 80,074 (1.5) 201,911 (2.0)
 Occupational health and safety insurance 108,774 (0.3) 94,770 (0.4) 124 (0.0) 13,868 (0.1)
 Private insurance 2,774 (0.0) 2,133 (0.0) 142 (0.0) 499 (0.0)
 Medical aid type 1 1,987,662 (5.4) 888,746 (4.2) 73,877 (1.3) 1,025,021 (10.0)
 Medical aid type 2 337,566 (0.9) 259,560 (1.2) 57,906 (1.1) 20,100 (0.2)
 General insurance 596,661 (1.6) 456,905 (2.1) 36,965 (0.7) 102,658 (1.0)
 Other 185,924 (0.5) 133,198 (0.6) 10,508 (0.2) 42,200 (0.4)
 Unknown 96,034 (0.3) 54,624 (0.3) 10,034 (0.2) 31,360 (0.3)
Route of arrival
 Direct visit 33,704,570 (90.9) 19,834,372 (93.1) 5,126,142 (93.2) 8,743,841 (85.0)
 Transfer from other hospital 2,786,344 (7.5) 1,197,493 (5.6) 325,863 (5.9) 1,262,981 (12.3)
 Referred from outpatient clinics 561,269 (1.5) 246,002 (1.2) 43,356 (0.8) 271,909 (2.6)
 Other 13,642 (0.0) 7,240 (0.0) 1,840 (0.0) 4,561 (0.0)
 Unknown 33,040 (0.1) 20,543 (0.1) 4,033 (0.1) 8,419 (0.1)
Transport
 119 Ambulance 7,540,276 (20.3) 3,653,827 (17.1) 468,942 (8.5) 3,417,462 (33.2)
 Other medical institution ambulance 234,759 (0.6) 83,574 (0.4) 6,638 (0.1) 144,542 (1.4)
 Other ambulance 962,218 (2.6) 318,770 (1.5) 24,056 (0.4) 619,384 (6.0)
 Police or official transport 40,390 (0.1) 35,135 (0.2) 1,361 (0.0) 3,892 (0.0)
 Air transport 22,516 (0.1) 13,856 (0.1) 2,063 (0.0) 6,597 (0.1)
 Other transport 27,570,000 (74.3) 16,740,000 (78.6) 4,895,705 (89.0) 5,936,108 (57.7)
 Walk-in 632,413 (1.7) 413,509 (1.9) 93,463 (1.7) 125,432 (1.2)
 Other 58,881 (0.2) 24,398 (0.1) 4,810 (0.1) 29,673 (0.3)
 Unknown 33,974 (0.1) 21,111 (0.1) 4,196 (0.1) 8,621 (0.1)
Initial triage (KTAS score)b)
 1 433,313 (1.2) 142,187 (0.7) 13,775 (0.3) 277,324 (2.7)
 2 1,768,107 (4.8) 750,860 (3.5) 148,111 (2.7) 869,113 (8.4)
 3 13,891,416 (37.4) 7,224,035 (33.9) 1,935,311 (35.2) 4,732,014 (46.0)
 4–5 19,827,228 (53.4) 12,465,924 (58.5) 3,265,397 (59.4) 4,095,783 (39.8)
 Other/unknown 1,178,801 (3.2) 722,644 (3.4) 138,640 (2.5) 317,477 (3.1)
Severe illness diagnosisc) 4,212,883 (11.4) 1,765,999 (8.3) 182,292 (3.3) 2,264,557 (22.0)
Length of stayd)
 Mean±SD (hr) 2.8 ± 9.8 2.4 ± 8.9 1.9 ± 9.9 4.3 ± 11.3
 Median (IQR) (hr) 1.7 (0.7–3.1) 1.5 (0.6–2.7) 1.1 (0.4–2.4) 2.5 (1.3–4.6)
 0–6 hr 33,529,765 (90.4) 19,799,501 (92.9) 5,247,371 (95.4) 8,482,680 (82.4)
 6–12 hr 2,302,211 (6.2) 981,546 (4.6) 191,904 (3.5) 1,128,754 (11.0)
 12–24 hr 883,020 (2.4) 365,174 (1.7) 47,259 (0.9) 470,585 (4.6)
 ≥24 hr 322,786 (0.9) 121,986 (0.6) 6,902 (0.1) 193,898 (1.9)
 Unknown 61,083 (0.2) 37,443 (0.2) 7,798 (0.1) 15,794 (0.2)
ED disposition
 Discharge 28,664,776 (77.3) 17,735,758 (83.2) 4,961,195 (90.2) 5,967,668 (58.0)
 Admissione) 7,428,617 (20.0) 3,148,829 (14.8) 496,811 (9.0) 3,782,930 (36.8)
  General ward 6,255,742 (16.9) 2,717,747 (12.8) 468,081 (8.5) 3,069,880 (29.8)
  Intensive care unit 1,139,056 (3.1) 411,771 (1.9) 27,642 (0.5) 699,630 (6.8)
 Transfer 613,224 (1.7) 253,858 (1.2) 24,618 (0.5) 334,737 (3.3)
 Hopeless discharge 2,523 (0.0) 570 (0.0) 48 (0.0) 1,905 (0.0)
 Death 247,944 (0.7) 71,147 (0.3) 2,667 (0.1) 174,120 (1.7)
 Other 90,239 (0.2) 63,810 (0.3) 9,490 (0.2) 16,939 (0.2)
 Unknown 51,542 (0.1) 31,678 (0.2) 6,405 (0.1) 13,412 (0.1)
Hospital disposition
 Discharge 34,875,444 (94.0) 20,536,840 (96.4) 5,441,353 (98.9) 8,897,076 (86.5)
 Transfer 1,272,225 (3.4) 444,129 (2.1) 32,193 (0.6) 795,888 (7.7)
 Hopeless discharge 6,466 (0.0) 1,826 (0.0) 71 (0.0) 4,569 (0.0)
 Death 643,034 (1.7) 159,152 (0.8) 4,109 (0.1) 479,762 (4.7)
 Other 111,287 (0.3) 72,422 (0.3) 10,186 (0.2) 28,679 (0.3)
 Unknown 190,409 (0.5) 91,281 (0.4) 13,322 (0.2) 85,737 (0.8)
Rank UMLS code No. of patients (%) KCD code No. of patients (%)
Total (n=37,098,865)
 1 Abdominal pain 3,946,827 (8.8) A099 (gastroenteritis and colitis of unspecified origin) 1,776,048 (4.8)
 2 Fever 3,530,106 (7.9) R1049 (unspecified abdominal pain) 1,054,325 (2.9)
 3 Dizziness 1,853,536 (4.1) R42 (lightheadedness) 1,024,586 (2.8)
 4 Headache 1,795,042 (4.0) R5099 (hyperpyrexia NOS) 927,726 (2.5)
 5 Dyspnea 1,416,604 (3.2) Z115 (special screening examination for other viral disease) 703,181 (1.9)
 6 Vomiting 1,088,639 (2.4) R51 (headache) 617,324 (1.7)
 7 Diarrhea 907,524 (2.0) S610 (open wound of finger(s) without damage to nail) 609,640 (1.7)
 8 Nausea 869,155 (1.9) U071 (coronavirus disease, virus identified [COVID-19, virus identified]) 607,018 (1.6)
 9 Generalized weakness 819,326 (1.8) S0600 (concussion, without open intracranial wound) 574,796 (1.6)
 10 Epigastric pain 805,449 (1.8) L509 (urticaria, unspecified) 457,785 (1.2)
 11 Chest pain 786,829 (1.8) R074 (chest pain, unspecified) 456,768 (1.2)
 12 Cough 766,726 (1.7) N201 (calculus of ureter) 447,421 (1.2)
 13 Sore throat 739,620 (1.7) J189 (pneumonia, unspecified) 425,612 (1.2)
 14 Back pain 704,491 (1.6) J069 (upper respiratory disease, acute) 390,925 (1.1)
 15 Myalgia 638,766 (1.4) T140 (superficial injury of unspecified body region) 338,815 (0.9)
Pediatric patients (<18 yr) (n=5,501,234)
 1 Fever 1,287,825 (23.9) R5099 (hyperpyrexia NOS) 405,286 (7.4)
 2 Abdominal pain 522,431 (9.7) A099 (gastroenteritis and colitis of unspecified origin) 367,155 (6.7)
 3 Vomiting 226,766 (4.2) R1049 (unspecified abdominal pain) 178,629 (3.3)
 4 Headache 137,165 (2.6) S0600 (concussion, without open intracranial wound) 138,802 (2.5)
 5 Cough 125,886 (2.3) B349 (viraemia NOS) 123,296 (2.3)
 6 Skin rash 115,726 (2.2) L509 (urticaria, unspecified) 115,099 (2.1)
 7 Urticaria 100,383 (1.9) J069 (upper respiratory disease, acute) 105,648 (1.9)
 8 Head trauma 82,159 (1.5) S018 (open wound of other parts of head) 104,287 (1.9)
 9 Pain in finger 78,938 (1.5) U071 (coronavirus disease, virus identified [COVID-19, virus identified]) 97,579 (1.8)
 10 Ankle pain 70,816 (1.3) J00 (acute rhinitis) 94,703 (1.7)
 11 Sore throat 66,482 (1.2) J029 (acute bronchitis, unspecified) 81,158 (1.5)
 12 Seizures 61,706 (1.1) J101 (seasonal influenza virus identified influenza with other respiratory manifestations) 76,562 (1.4)
 13 Dyspnea 61,571 (1.1) J111 (influenza with other respiratory manifestations, virus not identified) 71,384 (1.3)
 14 Pain in elbow 60,525 (1.1) T140 (superficial injury of unspecified body region) 64,390 (1.2)
 15 Diarrhea 45,409 (0.8) S010 (open wound of scalp) 63,683 (1.2)
Older adults (≥65 yr) (n=10,291,711)
 1 Abdominal pain 786,086 (7.8) R42 (lightheadedness) 443,418 (4.3)
 2 Dyspnea 735,053 (7.3) J189 (pneumonia, unspecified) 284,860 (2.8)
 3 Dizziness 659,342 (6.6) A099 (gastroenteritis and colitis of unspecified origin) 262,824 (2.6)
 4 Fever 586,141 (5.8) R1049 (unspecified abdominal pain) 216,558 (2.1)
 5 Generalized weakness 442,056 (4.4) U071 (coronavirus disease, virus identified [COVID-19, virus identified]) 202,537 (2.0)
 6 Headache 287,664 (2.9) R5099 (hyperpyrexia NOS) 159,802 (1.6)
 7 Chest pain 250,831 (2.5) I639 (cerebral infarction, unspecified) 152,858 (1.5)
 8 Back pain 198,484 (2.0) R060 (shortness of breath) 146,773 (1.4)
 9 Coxalgia 169,863 (1.7) R074 (chest pain, unspecified) 136,173 (1.3)
 10 Epigastric pain 142,541 (1.4) N390 (urinary tract infection, site not specified) 128,721 (1.3)
 11 Syncope 107,119 (1.1) S0600 (concussion, without open intracranial wound) 125,233 (1.2)
 12 Chest discomfort 101,352 (1.0) R51 (headache) 118,924 (1.2)
 13 Vomiting 97,364 (1.0) R53 (chronic debility) 117,842 (1.2)
 14 Low back pain 96,639 (1.0) Z115 (special screening examination for other viral diseases) 107,380 (1.1)
 15 Diarrhea 96,029 (1.0) K5909 (other and unspecified constipation) 106,371 (1.0)
Sex Year
 P for trend
2020 2021 2022 2023 2024a)
Total 15,562 16,093 17,973 20,322 16,543 0.378
 Male 16,873 17,102 19,150 21,650 17,860 0.362
 Female 14,250 15,084 16,797 18,995 15,226 0.398
Adults (18–64 yr) 11,913 12,147 12,336 13,051 10,341 0.558
 Male 12,071 11,871 11,899 12,450 10,016 0.297
 Female 11,755 12,424 12,772 13,651 10,667 0.830
Pediatric patients (<18 yr) 11,702 11,596 15,144 19,024 12,796 0.406
 Male 12,984 12,845 16,874 21,008 14,215 0.403
 Female 10,419 10,347 13,414 17,040 11,378 0.409
Older adults (≥65 yr) 23,380 25,048 28,684 32,736 29,140 0.085
 Male 26,682 28,096 32,279 36,917 33,231 0.073
 Female 20,078 21,999 25,090 28,554 25,050 0.102
Disease category No. of patients No. of patients per 1,000 ED visits ED discharge rate (%) Transfer rate (%) Admission rate (%) ICU admission rate (%) No. of hospital deaths In-hospital mortality (%)
Myocardial infarction 213,538 5.8 4.7 9.2 84.3 55.7 20,012 9.4
Ischemic stroke 546,175 14.7 15.0 4.3 80.4 23.2 27,359 5.0
Intracranial hemorrhage 142,413 3.8 6.3 10.9 81.5 57.4 20,613 14.5
Cardiac arrest (diagnosis code) 165,481 4.5 0.7 5.4 33.3 27.9 130,353 78.8
Cardiac arrest (diagnosis code or cardiopulmonary resuscitation in ED)a) 205,617 5.5 2.9 5.6 26.6 24.1 159,527 77.6
Subdural hemorrhage 53,370 1.4 4.0 16.5 77.4 65.8 8,894 16.7
Severe trauma 559,392 15.1 21.0 7.7 69.6 25.1 29,494 5.3
Sepsis (diagnosis code) 229,397 6.2 5.3 3.3 90.1 37.3 54,413 23.7
Sepsis (extended definition)a),b) 701,157 18.9 1.9 1.6 93.4 72.5 155,928 22.2
Aortic dissection 24,069 0.6 9.0 21.3 64.3 44.8 3,467 14.4
Biliary disease 358,891 9.7 11.7 6.0 82.1 6.5 10,224 2.8
Surgical diagnosis 261,395 7.0 5.8 5.5 88.2 12.3 12,608 4.8
GI bleeding/FB 428,153 11.5 22.4 3.8 72.9 18.5 25,468 5.9
Tracheal bleeding/FB 65,731 1.8 36.0 3.2 59.8 10.5 4,131 6.3
Intoxication 302,148 8.1 71.2 2.4 25.5 12.9 3,652 1.2
Perinatal disease 70,139 1.9 8.7 1.2 90.0 3.2 67 0.1
Premature (low birth weight) 17,465 0.5 15.8 1.4 82.7 61.0 109 0.6
Severe burn 1,312 0.0 17.9 18.5 61.7 33.3 144 11.0
Status epilepticus 24,218 0.7 9.9 4.9 84.9 44.5 1,746 7.2
Meningitis 54,079 1.5 28.9 2.0 68.9 13.5 1,893 3.5
Diabetic encephalopathy 47,813 1.3 9.0 5.9 83.8 45.1 3,977 8.3
Pulmonary embolism/DVT 106,614 2.9 17.2 2.8 79.2 22.2 10,313 9.7
Arrhythmia 403,265 10.9 22.3 2.0 75.2 26.4 31,470 7.8
ARDS/pulmonary edema 207,161 5.6 5.6 3.2 89.8 36.2 43,339 20.9
DIC 14,370 0.4 3.2 0.7 94.2 53.4 6,713 46.7
Intussusception/ileus 95,320 2.6 13.7 4.5 81.5 6.6 3,308 3.5
Amputation 36,441 1.0 23.9 5.2 69.3 30.2 1,241 3.4
Acute kidney injury 404,505 10.9 8.6 3.8 86.7 30.8 69,408 17.2
Ophthalmic emergency 40,811 1.1 55.8 0.4 43.6 3.1 209 0.5
Urologic emergency 19,529 0.5 69.4 1.3 29.2 1.4 69 0.4
TBIa),c) 246,811 6.7 19.5 8.7 70.7 38.8 18,118 7.3
Suicide attempt and self-harma),d) 209,746 5.7 63.4 3.9 29.1 15.5 8,129 3.9
COVID-19a) 907,336 24.5 63.7 2.2 32.8 4.7 28,482 3.1
Table 1. Patient demographics, ED visit characteristics, and outcome by age group

Values are presented as number (%), unless otherwise indicated. Percentages may not total 100 due to rounding.

ED, emergency department; KTAS, Korean Triage Acuity Scale; IQR, interquartile range; SD, standard deviation.

Patients with missing age information were excluded from the analysis (n=270).

Reporting not obligatory for level III EDs (recording KTAS scores became mandatory starting from 2021); hence, there is a higher likelihood of missing data for level III EDs.

28 Severe illness diagnosis codes are listed in Supplementary Table 1.

Any ED length of stay over 5 days was treated as 5 days.

Admission locations include areas other than general wards or intensive care units, including unspecified locations.

Table 2. Top 15 chief complaints by UMLS code and main diagnosis by KCD code

UMLS, Unified Medical Language System; KCD, Korean Standard Classification of Diseases.

Table 3. Age- and sex-standardized emergency department visits per 100,000 population (2020–2024)

All comparisons between 2023 and 2024 showed statistically significant differences.

Table 4. Summary of ED outcomes for 28 severe illness codes and selected diagnostic categories (including traumatic brain injury, suicide attempt/self-harm, and COVID-19)

ED, emergency department; ICU, intensive care unit; GI, gastrointestinal; FB, foreign body; DVT, deep vein thrombosis; ARDS, acute respiratory distress syndrome; DIC, disseminated intravascular coagulation; TBI, traumatic brain injury.

In addition to the 28 predefined severe illness codes, several diagnostic codes were additionally selected and included in this table.

(Infection diagnosis code AND ICU admission/ED death) OR sepsis/septic shock diagnosis code.

Identified based on International Classification of Diseases, 10th Revision (ICD-10) diagnostic codes (S06.1–S06.9) that correspond to the TBI definition established by the Korea Disease Control and Prevention Agency.

Any of the following three conditions: (1) the intention of self-harm or suicide; (2) initial severity classification falls into the suicide attempt, suicidal intent, or suicidal ideation categories under the Korean Triage and Acuity Scale (KTAS); or (3) discharge diagnosis codes based on the Korean Standard Classification of Disease (KCD), X60–X84 (excluding X65).

Table 1.

Table 2.

Table 3.

Table 4.

CEEM : Clinical and Experimental Emergency Medicine

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