Correction: Evaluation of class participation in non-face-to-face CPR training for medical students.

[This corrects the article DOI: 10.1371/journal.pone.0278273.].

Framework Development of Non-Face-to-Face Training of Basic Life Support for Laypersons: A Multi-Method Study.

The spread of infectious diseases has accelerated the transition from face-to-face (F2F) to non-F2F (NF2F) education. To maintain the effect of successful NF2F education in cardiopulmonary resuscitation, reorganizing the curriculum to suit the NF2F educational environment is necessary. We propose an appropriate learning curriculum for NF2F basic life support (BLS) training for laypersons based on expert surveys and learners' performance outcomes. This study included three stages and used multiple methods. A draft curriculum was created through a literature review and three-round Delphi approach, and then applied as a test for actual education. After the training, the final curriculum of the NF2F BLS training for laypersons was proposed by reflecting on the performance outcomes of learners and expert opinions. NF2F theoretical education was simplified into five content items: concept of chain of survival, legal protection for first aiders, importance of bystander cardiopulmonary resuscitation, how to recognize a patient in cardiac arrest and activate the emergency medical services system, and reduced training time. In the hands-on skills session, it was recommended to practice chest compressions using a simple intuitive feedback device and to use automated external defibrillators step-by-step more than in F2F training. In conclusion, NF2F training is a suitable option for BLS training methods in situations where F2F training is difficult.

Dexamethasone therapy prevents delayed neuropsychiatric sequelae after carbon monoxide poisoning: a prospective registry-based study.

BACKGROUND: Delayed neuropsychiatric sequelae are major complications of carbon monoxide poisoning; carbon monoxide triggers brain oxidation and inflammation. Corticosteroids such as dexamethasone modulate neurological damage after carbon monoxide poisoning through anti-inflammatory actions and immune response inhibition. However, it is not known whether corticosteroids prevent delayed neuropsychiatric sequelae. We thus studied whether dexamethasone reduced the incidence of delayed neuropsychiatric sequelae. METHODS: This registry-based study enrolled patients with carbon monoxide poisoning treated in a Korean tertiary care hospital from March 1st, 2020 to November 30th, 2021. Data of patients were prospectively collected during the study period, and retrospectively analyzed. One group received intravenous dexamethasone. We performed multivariable logistic regression analysis to identify factors associated with delayed neuropsychiatric sequelae. RESULTS: A total of 128 patients were enrolled, of which 99 patients received dexamethasone therapy and 29 patients did not. The incidences of delayed neuropsychiatric sequelae in the dexamethasone and non-dexamethasone groups were 16.2% and 37.9%, respectively. Multivariable logistic regression analysis revealed that dexamethasone use (odds ratio = 0.122, 95% confidence interval 0.031-0.489) and a higher Glasgow Coma Scale (odds ratio = 0.818, 95% confidence interval 0.682-0.981) was associated with a lower incidence of delayed neuropsychiatric sequelae. CONCLUSION: Early dexamethasone treatment was significantly associated with a decreased incidence of delayed neuropsychiatric sequelae. A higher Glasgow Coma Scale at presentation also was associated with a lower incidence of delayed neuropsychiatric sequelae.

Predictors for Distinguishing Renal Infarction From Urolithiasis in the Emergency Department: A Randomly Matched Retrospective Case-Control Study.

BACKGROUND: Emergency department (ED) clinicians may misdiagnose renal infarction (RI) as urolithiasis because RI is a rare disease with presenting symptoms similar to the symptoms of urolithiasis. However, earlier diagnosis of RI can improve patient prognosis. OBJECTIVES: We investigated potential predictors for distinguishing RI from urolithiasis based on clinical findings and laboratory results. METHODS: This randomly matched retrospective case-control study included patients who had been diagnosed with acute RI or acute urolithiasis between January 2016 and March 2020. Patients were excluded if they were aged under 18 years, had a history of trauma, or had incomplete medical records. Using a matching ratio of 1:4, RI patients were randomly matched to urolithiasis patients. Multivariable logistic regression was performed to identify factors that could distinguish RI from urolithiasis. RESULTS: In total, 48 patients were included in the RI group and 192 patients were included in the urolithiasis group. Multivariable logistic regression showed that age ≥ 65 years (odds ratio [OR] 6.155; p = 0.022), atrial fibrillation (OR 18.472; p = 0.045), current smoking (OR 17.070; p = 0.001), costovertebral angle tenderness (OR 0.179; p = 0.037), aspartate aminotransferase level ≥ 27.5 U/L (OR 6.932; p = 0.009), sodium level ≥ 138.5 mEq/L (OR 0.079; p = 0.004), and hematuria (OR 0.042; p = 0.001) were significant predictors that could distinguish RI from urolithiasis. Based on these results, a nomogram was constructed. CONCLUSION: Age ≥ 65 years, atrial fibrillation, current smoking, absence of costovertebral angle tenderness, aspartate aminotransferase level ≥ 27.5 U/L, sodium level < 138.5 mEq/L, and absence of hematuria were predictors that can distinguish between RI and urolithiasis.

Analyzing willingness for extracorporeal cardiopulmonary resuscitation in refractory ventricular fibrillation.

Extracorporeal cardiopulmonary resuscitation (ECPR) for refractory ventricular fibrillation/ventricular tachycardia in out-of-hospital cardiac arrest has recently been recommended for selected patients with favorable prognostic features. We aimed to identify factors affecting the willingness of emergency physicians to implement extracorporeal cardiopulmonary resuscitation (ECPR). We conducted a factorial survey with nine experimental vignettes by combining three different scene time intervals and transportation time intervals. Emergency physicians reported willingness to implement ECPR (1-100 points). Respondent characteristics that could affect the willingness were studied. Multilevel analysis of vignettes and respondent factors was conducted using a mixed-effects regression model. We obtained 486 vignette responses from 54 emergency physicians. In the case of longer scene time intervals, there was a significant difference in the willingness scores at 9 and 12 min transportation time intervals. When the pre-hospital time interval was > 40 min, emergency physicians demonstrated lower willingness to implement ECPR. Clinical experience of 15-19 years showed a significant favorable effect on willingness to implement extracorporeal membrane oxygenation (ECMO). However, the mean willingness scores of EPs for ECMO implementation were more than 75 across all vignettes. In ECPR, the prehospital time interval is an important factor, and the willingness of emergency physicians to implement ECMO could be mutually affected by scene time intervals, transportation time intervals, and total prehospital time.

The impact of COVID-19 pandemic on revisits to emergency department.

AIM: This study presents the impact of COVID-19 on revisits to the emergency department comparing revisit rates and characteristics between the pre-COVID-19 and COVID-19 periods. METHODS: This multi-center retrospective study included patients over 18 years of age who visited emergency departments during the pre-COVID-19 period and the COVID-19 pandemic. The revisit rates were analyzed according to five age groups; 18-34, 35-49, 50-64, 65-79, and ≥ 80 years, and three revisit time intervals; 3, 9, and 30 days. Also, we compared the diagnosis and disposition at revisit between the study periods. RESULTS: The revisit rates increased with age in both study periods and the revisit rates among all age groups were higher in the COVID-19 period. The proportion of infectious and respiratory diseases decreased during the COVID-19 period. The ICU admission rate and mortality at the revisit among patients aged ≥ 80 years were lower in the COVID-19 period than in the pre-COVID-19 period. CONCLUSION: The revisit rates increased with age in both study periods and there were several changes in the diagnosis and disposition at the revisit in the COVID-19 period.

Evaluation of class participation in non-face-to-face CPR training for medical students.

BACKGROUND: Cardiopulmonary resuscitation (CPR) education requires that learners practice key skills to promote mastery. Our aim in this study was to evaluate differences in post-education performance and class participation during CPR training between face-to- face (FF) and non-face-to-face (NFF) learning formats. METHODS: This was a randomized controlled study of third-year medical students from two university hospital, allocated to either the FF or NFF format for CPR education. The learning scenario addressed single-person CPR, consisting of chest compression only, and excluded breathing. The Kahoot! application was used for NFF. Between-group comparisons for class participation and CPR skills were based on video recordings. RESULTS: Seventy students participated in our study, with 35 randomly allocated to the FF and NFF groups. There were no between-group differences in terms of age, sex, previous basic life support training, and willingness and confidence in performing CPR. Compared to the FF group, the NFF group demonstrated significant differences during CPR, including fewer calling for assistance and using of defibrillator (p = 0.006), as well as fewer checking for breathing (p = 0.007), and fewer counting during chest compression (p = 0.006). Additionally, < 30% of learners in the NFF group completed rhythm analysis after the last defibrillator shock delivery and resumed immediate chest compression (p < 0.001). All students in both groups passed the post-training assessment. CONCLUSION: Class participation in NFF learning was lower than that in FF learning. Although the post-education evaluation in the NFF group was not inferior, efforts on promoting active participation in NFF learning are required.

Extremity Injuries during Sporting Activities According to Life Course: Focusing on Fractures.

Background: The increased participation in sports has led to an increased number of sports-related injuries. We aimed to identify the incidence of sports-related injuries by life course and the risk factors for sports-related extremity fractures. Methods: We analyzed data of patients with sports-related extremity injuries from Emergency Department-based national injury surveillance systems, obtained from Jan 2013 to Dec 2016. A multiple logistic regression analysis was performed to identify risk factors of extremity fracture by life course after adjusting for sex, injury season, injury time, injury place, sports type, and mechanism of injury. Results: Overall, 23385 patients met our inclusion criteria. Soccer injuries were most common in the 5-14-year (32.4%), 15-24-year (43.0%), and 25-44-year groups (32.7%), and hiking injuries were most common in the 45-64-year (23.6%) and ≥65-year age groups (38.0%). The upper extremity injury and fracture rates were higher in the younger-age group; nevertheless, the injury and fracture rates of the lower extremities increased with increasing age. Moreover, the rate of hip and thigh injuries and fractures increased significantly in the ≥65-year age group. Conclusion: The incidence and severity of sports injuries are affected by player factors and the sports activity itself. The age of players is a major determinant that affects their medical and physiologic conditions and the sport of choice. The strategy for preventing sports injuries should be structured based on age.

Application of the Team Emergency Assessment Measure for Prehospital Cardiopulmonary Resuscitation.

INTRODUCTION: Communication and teamwork are critical for ensuring patient safety, particularly during prehospital cardiopulmonary resuscitation (CPR). The Team Emergency Assessment Measure (TEAM) is a tool applicable to such situations. This study aimed to validate the TEAM efficiency as a suitable tool even in prehospital CPR. METHODS: A multi-centric observational study was conducted using the data of all non-traumatic out-of-hospital cardiac arrest patients aged over 18 years who were treated using video communication-based medical direction in 2018. From the extracted data of 1494 eligible patients, 67 sample cases were randomly selected. Two experienced raters were assigned to each case. Each rater reviewed 13 or 14 videos and scored the TEAM items for each field cardiopulmonary resuscitation performance. The internal consistency, concurrent validity, and inter-rater reliability were measured. RESULTS: The TEAM showed high reliability with a Cronbach's alpha value of 0.939, with a mean interitem correlation of 0.584. The mean item-total correlation was 0.789, indicating significant associations. The mean correlation coefficient between each item and the global score range was 0.682, indicating good concurrent validity. The mean intra-class correlation coefficient was 0.804, indicating excellent agreement. DISCUSSION: The TEAM can be a valid and reliable tool to evaluate the non-technical skills of a team of paramedics performing CPR.

Emergency Transport Refusal during the Early Stages of the COVID-19 Pandemic in Gyeonggi Province, South Korea.

We analyzed the changes in patients' clinical characteristics and transport refusal pre- and post-COVID-19 and identified the reasons for transport refusal using emergency medical services run sheet data from pre-COVID-19 (April−December 2019) and post-COVID-19 (April−December 2020) in Gyeonggi Province, South Korea. We included patients aged ≥18 years. Univariate and multivariate logistic regression analyses were performed to identify the relationship between patients' personal factors and clinical characteristics and emergency transport refusal. During the control and study periods, 612,681 cases were reported; the transport refusal rates during the control and study periods were 6.7% and 8.2%, respectively. Emergency transport refusal was associated with younger age, the male sex, a normal mental status, a shock index < 1, and trauma in both the pre- and post-COVID-19 periods. Although fever prevented transport refusal during the pre-COVID-19 period (aOR, 0.620; 95% CI, 0.567−0.679), it became a significant risk factor for transport refusal during the post-COVID-19 period (aOR, 1.619; 95% CI, 1.534−1.709). The most common reason for transport refusal by critically ill patients was "because it was not accepted within the jurisdiction and remote transport was required." It is necessary to expand the response capacity of patients with fever in the community to reduce the refusal of transport by critically ill patients.

A Comparison of Emergency Department Revisit Rates of Pediatric Patients between Pre-COVID-19 and COVID-19 Periods.

Unscheduled revisits to emergency departments (EDs) are important because they indicate the quality of emergency care. However, the characteristics of pediatric patients visiting EDs changed during the coronavirus disease (COVID-19) pandemic, and these changes may have affected their revisit patterns. Therefore, we aimed to compare the ED revisit patterns of pediatric patients between the pre-COVID-19 and COVID-19 periods. This retrospective multicenter study included patients aged below 18 years who visited the ED in the pre-COVID-19 and COVID-19 periods. ED revisit rates were analyzed using five age groups and three visit-revisit intervals. In the pre-COVID-19 period, the revisit rates decreased with increasing age. In the COVID-19 period, the revisit rates were the lowest for the group aged 4-6 years, and the rates increased for those aged ≥7 years. In conclusion, there were changes in the patterns of revisit rates of pediatric patients according to age between the pre-COVID-19 and COVID-19 periods. Therefore, it is necessary to identify the reasons for revisits according to age and establish strategies to reduce the revisit rates of pediatric patients.

Nurse evaluation of stress levels during CPR training with heart rate variability using smartwatches according to their personality: A prospective, observational study.

BACKGROUND: Cardiopulmonary resuscitation (CPR) is a very critical phenomenon, and to prepare for it, most nurses undertake simulation training, during which learners' stress levels should be managed. This study aims to evaluate nurses' stress levels during CPR simulation training using heart rate variability (HRV) measured with a smartwatch and to determine the correlation between individual personality traits and stress levels. METHODS: This prospective observational study was conducted from July 2020 to December 2021. For nurses participating in advanced life support training with more than six months of clinical experience, their stress levels while performing as a CPR team leader were measured. Regarding stress levels, heart rate data measured with a smartwatch were processed using Kubios HRV Standard software to generate HRV parameters. The personality of participants was evaluated using the Big Five personality test. The degree of stress according to personality was determined using HRV parameters. Consequently, the correlation between personality and stress according to the clinical experience of cardiac arrest was analyzed. RESULTS: Of the 132 participants, 91.7% were female, and the median age of the sample was 27 years. Agreeable personality had the highest score (32.84±3.83). LF power (r = 0.18, p = 0.04) and HF power (r = 0.20, p = 0.02) showed a significant positive correlation with the agreeableness trait. In subgroup analysis according to the cardiac arrest experience, the agreeableness trait had a positive correlation with a standard deviation of NN intervals (r = 0.24, p = 0.01), root-mean-square of successive differences (r = 0.23, p = 0.02), LF Power (r = 0.26, p = 0.01), and HF power (r = 0.23, p = 0.02), but a negative correlation with mean HR (r = -0.22, p = 0.03). CONCLUSION: The clinical experience in cardiac arrest and agreeableness were related to acute stress during training. In the future, it is necessary to apply a scenario of a level suitable for individual personality and experience, and evaluate the level and achievement of students.

Unintended beneficial effects of COVID-19 on influenza-associated emergency department use in Korea.

BACKGROUND: Non-pharmaceutical interventions, including hand hygiene, wearing masks, and cough etiquette, and public health measures such as social distancing, used to prevent the spread of coronavirus disease 2019 (COVID-19), could reduce the incidence rate of respiratory viral infections such as influenza. We evaluated the effect of COVID-19 on the incidence of influenza in Korea. METHODS: This retrospective study included all patients who visited five urban emergency departments (EDs) during the influenza epidemic seasons of 2017-18, 2018-19, and 2019-20. Influenza was defined as ICD-10 codes J09, J10, and J11, determined from ED discharge records. The weekly incidence rates of influenza per 1000 ED visits during the 2019-20 season, when COVID-19 became a pandemic, were compared with those of 2017-18 and 2018-19. The actual incidence rate of the 2019-20 season was compared with the predicted value using a generalized estimation equation model based on 2017-18 and 2018-19 data. RESULTS: The weekly influenza incidence rate decreased from 101.6 to 56.6 between week 4 and week 5 in 2020 when the first COVID-19 patient was diagnosed and public health measures were implemented. The weekly incidence rate during week 10 and week 22 of the 2019-20 season decreased most steeply compared to 2017-18 and 2018-19. The actual influenza incidence rate observed in the 2019-20 season was lower than the rate predicted in the 2017-18 and 2018-19 seasons starting from week 7 when a COVID-19 outbreak occurred in Korea. CONCLUSIONS: The implementation of non-pharmaceutical interventions and public health measures for the COVID-19 epidemic effectively reduced the transmission of influenza and associated ED use in Korea. Implementing appropriate public health measures could reduce outbreaks and lessen the burden of influenza during future influenza epidemics.

Effects of Smart Advanced Life Support protocol implementation including CPR coaching during out-of-hospital cardiac arrest.

PURPOSE: The aim of this study was to compare out-of-hospital cardiac arrest (OHCA) outcomes before and after implementation of Smart Advanced Life Support (SALS) protocol incorporating changes in cardiopulmonary resuscitation (CPR) assistance and coaching by physicians via real-time video calls. METHODS: A prospective before-and-after multi-regional observational study was conducted between January 2014 and December 2018. In January 2016, emergency medical service (EMS) providers adopted an integrated CPR coaching by physicians via real-time video call via SALS to treat patients with OHCA focusing on high-quality cardiopulmonary resuscitation. Propensity score matching was performed to match patients. Patients' outcomes using conventional protocol were then compared with those of patients using the SALS protocol. RESULTS: Among 26,349 OHCA cases, 2351 patients and 7261 patients were enrolled during the pre-intervention and the post-intervention periods, respectively. Multivariate analysis showed that SALS was independently associated with favorable neurological outcomes [odds ratio (OR): 2.20; 95% confidence interval (CI): 1.62-2.99]. A total of 2096 patients were propensity score-matched and the two groups were well balanced. In the matched cohort, the use of SALS protocol was still associated with increased prehospital return of spontaneous circulation (ROSC) (OR: 3.83, 95% CI: 2.80-5.26), survival to discharge (OR: 1.68; 95% CI: 1.20-2.34), and favorable neurological outcomes (OR: 1.83; 95% CI: 1.19-2.82). CONCLUSION: A multidisciplinary SALS protocol for the resuscitation of patients with OHCA was associated with increased prehospital ROSC, survival to discharge, and good neurologic outcomes compared with traditional resuscitation protocol.

Clinical Characteristics Associated with Physical Violence in the Elderly: A Retrospective Multicenter Analysis.

BACKGROUND: Elder abuse is predicted to increase with the rapid population ageing in many countries. Violent injury is influenced by individual factors as well as interpersonal and social relationships, with different manifestations based on changes in the socioeconomic position of older adults. We comparatively investigated the clinical and injury characteristics of physical violence in the elderly with those in another age group. METHODS: We included elderly patients (age ≥65 years) who visited six emergency departments (ED) with violence-induced injuries in 2017. The control group comprised patients aged 45-64 years, selected by 1:2 matching based on hospital and sex. Data were extracted from the National Emergency Department Information System and electronic medical records. Both groups were compared for injury mechanism, injury location, activity during injury, diagnosis, and clinical outcomes. RESULTS: Among the 316,944 patients who presented to the 6 ED, 89,178 (28.1%) had traumatic injuries, and 1.6% and 4.5% of injuries were sustained due to violence in the ≥65 and 45-64 year age groups, respectively. There were no significant intergroup differences in the perpetrator (P=0.27), body parts affected (P=0.63), and diagnosis (P=0.23), whereas the older adult group had a significantly higher proportion of traumatic injury by fall (P=0.01), at road and traffic facilities (P=0.01), during work (P=0.01), and multiple injuries (P<0.01). CONCLUSION: The increase in non-regular workers in the elderly after retirement may have increased the risk of traumatic workplace injuries. As workplace injuries may be a new risk factor for physical violence in the elderly, institutional workplace injury prevention policy is needed.

Factors for return to emergency department and hospitalization in elderly urinary tract infection patients.

BACKGROUND: Appropriate decision of emergency department (ED) disposition is essential for improving the outcome of elderly urinary tract infection (UTI) patients. However, studies on early return visit (ERV) to the ED in elderly UTI patients are limited. Therefore, we aimed to identify factors for ERV and hospitalization after return visit (HRV) in this population. METHODS: Elderly patients discharged from the ED with International Classification of diseases 10th Revision codes of UTI were selected from the registry for evaluation of ED revisit in 6 urban teaching hospitals. Retrospective data were extracted from the electronic medical records and ERV and hospitalization to scheduled revisit (SRV) were compared. RESULT: Among a total of 419 patients found in the study period, 45 were ERV patients and 24 were HRV patients. Absence of UTI-specific symptoms (odds ratio [OR] 2.789; 95% confidence interval [CI] 1.368-5.687; P = 0.005), C-reactive protein (CRP) levels >30 mg/L (OR 2.436; 95% CI 1.017-3.9; P = 0.024), and body temperature ≥ 38 °C (OR 1.992; 95% CI 1.017-3.9; P = 0.044) were independent risk factors for ERV, and absence of UTI-specific symptoms (OR 3.832; 95% CI 1.455-10.088; P = 0.007), CRP levels >30 mg/L (OR 3.224; 95% CI 1.235-8.419; P = 0.017), and systolic blood pressure ≤ 100 mmHg (OR 3.795;95% CI 1.156-12.462; P = 0.028) were independent risk factors for HRV. However, there was no significant difference in empirical antibiotic resistance in ERV and HRV patients, compared to SRV patients. CONCLUSION: The independent risk factors of ERV and HRV should be considered for ED disposition in elderly UTI patients; the resistance to empirical antibiotics was not found to affect ERV or HRV within 3 days.

Prioritising Risk Factors for Prescription Drug Overdose among Older Adults in South Korea: A Multi-Method Study.

Older adults are vulnerable to drug overdose. We used a multi-method approach to prioritise risk factors for prescription drug overdose among older adults. The study was conducted in two stages. First, risk factors for drug overdose were classified according to importance and changeability through literature review, determined through 2-phase expert surveys. Second, prescription drug overdose cases during 2011-2015 were selected from a national cohort; the prevalence of 'more important' or 'more changeable' factors determined in stage one was investigated. Scores were assigned according to the Basic Priority Rating Scale formula, reflecting the problem size and seriousness and intervention effectiveness. In the first stage, polypharmacy, old-old age, female sex, chronic disease, psychiatric disease, and low socioeconomic status (SES) were selected as risk factors. In the second stage, 93.9% of cases enrolled had chronic medical disease; 78.3% were using multiple drugs. Low SES was more prevalent than other risk factors. As per the scoring formula, chronic medical disease, polypharmacy, psychiatric disease, low SES, female sex, and old-old age were the most important risk factors in order of priority. Patients with chronic medical disease and those using multiple medications should be prioritised in overdose prevention interventions among older adults.

Instructor-led distance learning for training students in cardiopulmonary resuscitation: A randomized controlled study.

STUDY HYPOTHESIS: Cardiopulmonary resuscitation (CPR) training can increase the likelihood of patient survival and better neurological outcomes. However, conventional learning (CL) has cost, time, and space constraints. This study aimed to evaluate whether laypersons who completed instructor-led distance learning (DL) acquired a level of CPR skill comparable to that achieved via CL training. METHODS: This randomized controlled study recruited students from 28 Korean high schools who were randomized to complete instructor-led DL or CL training. The CL training involved classroom-based face-to-face training, whereas the instructor-led DL training was provided online using a videoconferencing system. RESULTS: The study enrolled 62 students who were randomized to the CL group (31 participants) or the DL group (31 participants). Relative to the CL group, the DL group achieved remarkably similar results in terms of most CPR variables. In addition, the DL group had a significant improvement in the mean compression depth (before: 46 mm [interquartile range: 37-52 mm] vs. after: 49 mm [interquartile range: 46-54 mm], p<0.001). CONCLUSIONS: Instructor-led DL can be a suitable alternative to CL for providing CPR training to laypersons. In settings like the current COVID-19 pandemic, where face-to-face CL is not practical, DL may be a useful tool for delivering CPR training.

Higher Frequency of Undetected Acute Coronary Syndrome in Elderly Patients with Chest Pain Who Visited the Emergency Department: A Large-Cohort Retrospective Study.

BACKGROUND: Acute coronary syndrome (ACS) is a critical disease encountered in the emergency department (ED). Despite the development of diagnostic tools, it may be difficult to diagnose ACS because of atypical symptoms and equivocal test results. We investigated the difference in the rates of revisit and undetected ACS between adult and elderly patients who visited the ED with chest pain. METHOD: Data from 11,323 patients who visited the ED with chest pain at university hospitals in Korea were retrospectively analyzed. The cohort was categorized into two age groups: the adult (30-64 years) and elderly (>65 years). Baseline characteristic data (age, sex, vital signs, triage category, etc.) were obtained. We selected patients who revisited the ED within 30 d and investigated whether ACS was diagnosed. RESULT: The revisit rate was higher in the elderly (12%) than in the adult group (8.3%). The rate of undetected ACS among the revisited patients was 2.91% (18/7,186) in adults and 6.08% (16/1,998) in elderly patients. CONCLUSION: Elderly patients with chest pain had an increased rate of ED revisits and undetected ACS than adult patients. We recommend that old patients should be hospitalized to observe the progression of cardiac complaints or receive short-term follow-up.