Spatiotemporal Analysis of Out-ofHospital Cardiac Arrest Incidence and Survival Outcomes in Korea (2009–2021)

Background@#Out-of-hospital cardiac arrest is a major public health concern in Korea.Identifying spatiotemporal patterns of out-of-hospital cardiac arrest incidence and survival outcomes is crucial for effective resource allocation and targeted interventions. Thus, this study aimed to investigate the spatiotemporal epidemiology of out-of-hospital cardiac arrest in Korea, with a focus on identifying high-risk areas and populations and examining factors associated with prehospital outcomes. @*Methods@#We conducted this population-based observational study using data from the Korean out-of-hospital cardiac arrest registry from January 2009 to December 2021. Using a Bayesian spatiotemporal model based on the Integrated Nested Laplace Approximation, we calculated the standardized incidence ratio and assessed the relative risk to compare the spatial and temporal distributions over time. The primary outcome was out-ofhospital cardiac arrest incidence, and the secondary outcomes included prehospital return of spontaneous circulation, survival to hospital admission and discharge, and good neurological outcomes. @*Results@#Although the number of cases increased over time, the spatiotemporal analysis exhibited a discernible temporal pattern in the standardized incidence ratio of out-ofhospital cardiac arrest with a gradual decline over time (1.07; 95% credible interval [CrI], 1.04–1.09 in 2009 vs. 1.00; 95% CrI, 0.98–1.03 in 2021). The district-specific risk ratios of survival outcomes were more favorable in the metropolitan and major metropolitan areas.In particular, the neurological outcomes were significantly improved from relative risk 0.35 (0.31–0.39) in 2009 to 1.75 (1.65–1.86) in 2021. @*Conclusion@#This study emphasized the significance of small-area analyses in identifying high-risk regions and populations using spatiotemporal analyses. These findings have implications for public health planning efforts to alleviate the burden of out-of-hospital cardiac arrest in Korea.

Epidemiology of Non-Emergent Cancer-Related Emergency Department Visits in Korea between 2016 and 2020

Purpose@#As people living with cancer increase in the aging society, cancer-related emergency department (ED) visits are also increasing. This study aimed to investigate the epidemiologic characteristics of non-emergent cancer-related ED visits using a nationwide ED database. @*Materials and Methods@#A cross-sectional study was conducted using the National Emergency Department Information System (NEDIS) database. All cancer-related ED visits between 2016 and 2020 were included. The study outcome was non-emergent ED visits, defined as patients triaged into non-emergent condition at both the time of arrival at ED and discharge from ED and were discharged without hospitalization. @*Results@#Among 1185871 cancer-related ED visits over 5 years, 19.0% (n=225491) were classified as non-emergent visits. While abdominal pain and fever are the top chief complaints in both emergent and non-emergent visits, non-emergent visits had high proportions of abdomen distension (4.8%), ascite (2.4%), and pain in lower limb (2.0%) compared with emergent visits. The cancer types with a high proportion of non-emergent visits were thyroid (32.4%) and prostate cancer (30.4%). Adults compared with children or older adults, female, medical aid insurance, urban/rural ED, direct-in compared with transfer-in, and weekend visit were associated with high odds for non-emergent visits. @*Conclusion@#Approximately 20% of cancer-related ED visits may be potentially non-emergent. A significant number of non-emergent patients visited the ED due to cancer-related symptoms. To improve the quality of care for people living with cancer, the expansion of supportive care resources besides of ED, including active symptom control, is necessary.

Pediatric Age-Adjusted Shock Index as a Predictor of Mortality by Sex Disparity in Pediatric Trauma: A Pan-Asian Trauma Outcome Study

Purpose@#There has been no report of sex-specific, pediatric age-adjusted shock index (PASI) for pediatric trauma patients in previous studies. We aimed to determine the association between the PASI and in-hospital mortality of pediatric trauma patients and whether this association differs depending on sex. @*Materials and Methods@#This is a prospective, multinational, and multicenter cohort study using the Pan-Asian Trauma Outcome Study (PATOS) registry in the Asia-Pacific region, conducted in pediatric patients who visited the participating hospitals. The main exposure of our study was abnormal (elevated) PASI measured in an emergency department. The main outcome was in-hospital mortality. We performed a multivariable logistic regression analysis to estimate the association between abnormal PASI and study outcomes after adjusting for potential confounders. An interaction analysis between PASI and sex was also conducted. @*Results@#Of 6280 pediatric trauma patients, 10.9% (686) of the patients had abnormal PASI. In multivariable logistic regression analysis, abnormal PASI was significantly associated with increased in-hospital mortality [adjusted odds ratios (aOR), 1.74; 95% confidence interval (CI), 1.13–2.47]. Abnormal PASI had interaction effects with sex for in-hospital mortality (aOR, 1.86; 95% CI, 1.19–2.91 and aOR, 1.38; 95% CI, 0.58–2.99 for male and female, respectively) (p<0.01). @*Conclusion@#Abnormal PASI is associated with increased in-hospital mortality in pediatric trauma patients. The prediction power of PASI for in-hospital mortality was maintained only in male patients.

Circulating Vitamin D Level and Risk of Sudden Cardiac Death and Cardiovascular Mortality:A Dose-Response Meta-Analysis of Prospective Studies

Background@#We conducted a comprehensive meta-analysis of prospective cohort studies to analyze the effect of circulating vitamin D level on the risk of sudden cardiac death (SCD) and cardiovascular disease (CVD) mortality. @*Methods@#Prospective cohort studies evaluating the association between circulating vitamin D and risk of SCD and CVD mortality were systematically searched in the PubMed and Embase. Extracted data were analyzed using a random effects model and results were expressed in terms of hazard ratio (HR) and 95% confidence interval (CI). Restricted cubic spline analysis was used to estimate the dose-response relationships. @*Results@#Of the 1,321 records identified using the search strategy, a total of 19 cohort studies were included in the final meta-analysis. The pooled estimate of HR (95% CI) for low vs. high circulating vitamin D level was 1.75 (1.49–2.06) with I 2 value of 30.4%. In subgroup analysis, strong effects of circulating vitamin D were observed in healthy general population (pooled HR, 1.84; 95% CI, 1.43–2.38) and the clinical endpoint of SCD (pooled HRs, 2.68; 95% CI, 1.48– 4.83). The dose-response analysis at the reference level of < 50 nmol/L showed a significant negative association between circulating vitamin D and risk of SCD and CVD mortality. @*Conclusion@#Our meta-analysis of prospective cohort studies showed that lower circulating vitamin D level significantly increased the risk of SCD and CVD mortality.

Interactions between Sleep Apnea and Coronary Artery Disease on the Incidence of Sudden Cardiac Arrest: A Multi-Center Case-Control Study

Purpose@#Sleep apnea (SA) is a risk factor for coronary artery disease (CAD), and SA and CAD increase the incidence of sudden cardiac arrest (SCA). This study aimed to investigate the effect of SA on the incidence of SCA and explore the effect of varying degrees of SA with or without CAD on the incidence of SCA. @*Materials and Methods@#This prospective multi-center, case-control study was performed using the phase II Cardiac Arrest Pursuit Trial with Unique Registry and Epidemiologic Surveillance (CAPTURES-II) database for SCA cases and community-based controls in Korea. The matching ratio of cases to controls was 1:1, and they were randomly matched within demographics, including age, sex, and residence. The primary variable was a history of SA, and the second variable was a history of CAD. We conducted a conditional logistic regression analysis to estimate the effect of SA and CAD on the SCA risk, and an interaction analysis between SA and CAD. @*Results@#SA was associated with an increased risk of SCA [adjusted odds ratio (AOR) (95% confidence interval, CI): 1.54 (1.16–2.03)], and CAD was associated with an increased risk of SCA [AOR (95% CI): 3.94 (2.50–6.18)]. SA was a risk factor for SCA in patients without CAD [AOR (95% CI): 1.62 (1.21–2.17)], but not in patients with CAD [AOR (95% CI): 0.56 (0.20–1.53)]. @*Conclusion@#In the general population, SA is risk factor for SCA only in patients without CAD. Early medical intervention for SA, especially in populations without pre-existing CAD, may reduce the SCA risk.ClinicalTrials.gov (NCT03700203)

Changes and their prognostic implications of the National Early Warning Score (NEWS) in interhospital transferred critically ill patients

Objective@#This study aimed to investigate the association between the change in the National Early Warning Score (NEWS) before and after interhospital transport and the survival of critically ill patients transported by critical care transport. @*Methods@#A retrospective analysis of SMICU (Seoul Mobile Intensive Care Unit) transfer records and the National Emergency Department Information System (NEDIS) was conducted. Adult patients who used SMICU from 2016 to 2018 were included. Trauma patients and post-cardiac arrest patients were excluded. The NEWS before departure from the transferring hospital and the NEWS before the arrival at the receiving hospital were extracted, and the difference between both NEWS (△ NEWS) was calculated. The △ NEWS was categorized into three groups: -2 or less, -1 to 1, and 2 or more. The primary outcome was 24-hour post-transport mortality. Multivariable logistic regression was applied to calculate the adjusted odds ratio (AOR) and 95% confidence interval (CI) for the outcomes. @*Results@#Of the total number of 1,837 patients, 1,065 patients were included. △ NEWS were -2 or less in 131 (12.3%), -1 to 1 in 805 (75.6%), and 2 or more in 129 (12.1%) of the patients. The 24-hour mortality rate was 3.1%, 2.9%, and 7.0% in the △ NEWS≤-2, -1≤△ NEWS≤1, and △ NEWS≥2 groups, respectively. Relative to -1≤△ NEWS≤1, the AORs for the 24-hour mortality were 1.11 (95% CI, 0.38-3.29) in △ NEWS≤-2 and 2.56 (95% CI, 1.15-5.70) in △ NEWS≥2. @*Conclusion@#The changes in NEWS in critical care interhospital transport are associated with patient prognosis.

Concurrent external validation of various out-of-hospital cardiac arrest prognostication scores in a Korean population: a multicenter retrospective cohort study

Objective@#Various out-of-hospital cardiac arrest (OHCA) prognostication scores have been developed. However, the application of these scores is often limited owing to missing predictor variables. This study aimed to compare and validate various OHCA prognostication scores using simple imputation methods that can easily be applied in clinical situations. @*Methods@#Adult patients presenting with OHCA with a sustained return of spontaneous circulation (ROSC) between October 2015 and June 2020 were the subjects for the analysis. We evaluated six OHCA prognostication scores: the ROSC after cardiac arrest (RACA) score, CaRdiac Arrest Survival Score (CRASS), NULL-PLEASE, predictive score (PS), cardiac arrest hospital prognosis (CAHP) score, and the OHCA score. For missing predictors, median imputation for continuous variables and mode imputation for categorical variables were performed before the analysis. We evaluated the discrimination and calibration powers of each prognostic score for good neurological recovery at discharge. The area under the receiver operating characteristic curve (AUC) was used to assess the discrimination power, and a calibration plot and the Hosmer-Lemeshow test were used to assess the calibration power. @*Results@#Of the 12,321 patients, 5,191 were subjected to analysis. Among them, 924 (17.8%) had good neurological recovery. Certain predictors often had missing values-no-flow time 1,107 (21.3%), low-flow time 862 (16.6%), pH 1,104 (21.3%), lactate 1,820 (35.0%), and creatinine 2,257 (43.5%). After imputing the missing variables, the CAHP score showed the highest AUC (0.957; 95% confidence interval, 0.950-0.963), and the CRASS and PS also presented excellent discrimination power (AUC 0.914 and 0.942, respectively). However, the CAHP and NULL-PLEASE scores were well calibrated (Hosmer-Lemeshow test, P>0.05). @*Conclusion@#Among the six prognostic scores, the CAHP score showed the highest discrimination and calibration powers.

Association of transport time interval with neurologic outcome in out-of-hospital cardiac arrest patients without return of spontaneous circulation on scene and the interaction effect according to prehospital airway management

Objective@#This study analyzed the association of transport time interval (TTI) with survival rate and neurologic outcome in out-of-hospital cardiac arrest (OHCA) patients without return of spontaneous circulation (ROSC) and the interaction effect of TTI according to prehospital airway management. @*Methods@#A retrospective observational study based on the nationwide OHCA database from January 2013 to December 2017 was designed. Emergency medical service (EMS)-treated OHCA patients aged ≥18 years were included. TTI was categorized into four groups of quartiles (≤4, 5–7, 8–11, ≥12 minutes). The primary outcome was favorable neurologic outcome at discharge. The secondary outcome was survival to discharge from the hospital. Multivariable logistic regression was used to analyze outcomes according to TTI. A different effect of TTI according to the administration of prehospital EMS advanced airway was evaluated. @*Results@#In total, 83,470 patients were analyzed. Good neurologic recovery decreased as TTI increased (1.0% for TTI ≤4 minutes, 0.9% for TTI 5–7 minutes, 0.6% for TTI 8–11 minutes, and 0.5% for TTI ≥12 minutes; P for trend <0.05). The adjusted odds ratio of prolonged TTI (≥12 minutes) was 0.73 (95% confidence interval, 0.57–0.93; P<0.01) for good neurologic recovery. However, the negative effect of prolonged TTI on neurological outcome was insignificant when advanced airway or entotracheal intubation were performed by EMS providers (adjusted odds ratio, 1.17; 95% confidence interval, 0.42–3.29; P=0.76). @*Conclusion@#EMS TTI was negatively associated with the neurologic outcome of OHCA without ROSC on scene. When advanced airway was performed on scene, TTI was insignificantly associated with the outcome.

Analysis of the Impact of the Coronavirus Disease Epidemic on the Emergency Medical System in South Korea Using the Korean Triage and Acuity Scale

Purpose@#Severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), has spread worldwide. Global health systems, including emergency medical systems, are suffering from a lack of medical resources. Using a method for classifying patients visiting the emergency department (ED), we aimed to investigate trends in emergency medical system usage during the COVID-19 epidemic in Korea. @*Materials and Methods@#This retrospective observational study included patients who visited emergency medical institutions registered with the National Emergency Department Information System database from January 1, 2017 to May 31, 2020. The primary outcome was identification of changes in the distribution of patients visiting the ED according to the type of emergency medical institution. The secondary outcome was a detailed comparison of Korean Triage and Acuity Scale (KTAS) levels and patient distributions before and during the infectious disaster crisis period. @*Results@#Severe patients visited regional emergency centers (RECs) and local emergency centers (LECs) more frequently during the COVID-19 period, and disposition status warranting admission to the intensive care unit or resulting in death was more common in RECs and LECs during the COVID-19 period [RECs, before COVID-19: 300686 (6.3%), during COVID-19: 33548 (8.0%) (p<0.001); LECs, before COVID-19: 373593 (3.7%), during COVID-19: 38873 (4.5%) (p<0.001)]. @*Conclusion@#During the COVID-19 period, severe patients were shifted to advanced emergency medical institutions, and the KTAS better reflected severe patients. Patient distribution according to the stage of emergency medical institution improved, and validation of the KTAS triage increased more in RECs.

Association between the number of prehospital defibrillation attempts and neurologic outcomes in out-of-hospital cardiac arrest patients without on-scene return of spontaneous circulation

Objective@#Delivery of prehospital defibrillation for shockable rhythms by emergency medical service providers is crucial for successful resuscitation in out-of-hospital cardiac arrest (OHCA) patients. The optimal range of prehospital defibrillation attempts for refractory shockable rhythms is unknown. This study evaluated the association between the number of prehospital defibrillation attempts and neurologic outcomes in OHCA patients. @*Methods@#A retrospective observational study was conducted using the nationwide OHCA registry. Adult OHCA patients who were treated by emergency medical service providers due to presumed cardiac origin with initial shockable rhythm were enrolled from 2013 to 2016. The final analysis was performed on patients without on-scene return of spontaneous circulation. The number of prehospital defibrillation attempts was categorized as follows: 2–3, 4–5, and ≥6 attempts. The primary outcome was a good neurologic recovery at hospital discharge. Multivariate logistic regression analysis was performed to evaluate the association between neurologic outcomes and the number of prehospital defibrillation attempts. @*Results@#A total of 4,513 patients were included in the final analysis. The numbers of patients for whom 2–3, 4–5, and ≥6 defibrillation attempts were made were 2,720 (60.3%), 1,090 (24.2%), and 703 (15.5%), respectively. Poorer outcomes were associated with ≥6 defibrillation attempts: survival to hospital discharge (adjusted odds ratio, 0.38; 95% confidence interval, 0.21–0.65) and good neurologic recovery (adjusted odds ratio, 0.42; 95% confidence interval, 0.21–0.84). @*Conclusion@#Six or more prehospital defibrillation attempts were associated with poorer neurologic outcomes in OHCA patients with an initial shockable rhythm who were unresponsive to on-scene defibrillation and resuscitation.

Interaction Effects between COVID-19 Outbreak and Community Income Levels on Excess Mortality among Patients Visiting Emergency Departments

Background@#The objective of this study was to examine the effect of the coronavirus disease 2019 (COVID-19) outbreak on excess in-hospital mortality among patients who visited emergency departments (EDs) and to assess whether the excess mortality during the COVID-19 pandemic varies by community income level. @*Methods@#This is a cross-sectional study using the National Emergency Department Information System (NEDIS) database in Korea. The study population was defined as patients who visited all 402 EDs with medical conditions other than injuries between January 27 and May 31, 2020 (after-COVID) and for the corresponding time period in 2019 (before-COVID). The primary outcome was in-hospital mortality. The main exposure was the COVID-19 outbreak, and the interaction variable was county per capita income tax. We calculated the risk-adjusted in-hospital mortality rates by COVID-19 outbreak, as well as the difference-in-difference of risk-adjusted rates between the before-COVID and after-COVID groups according to the county income tax using a multilevel linear regression model with the interaction term. @*Results@#A total of 11,662,167 patients (6,765,717 in before-COVID and 4,896,450 in afterCOVID) were included in the study with a 1.6% crude in-hospital mortality rate. The riskadjusted mortality rate in the after-COVID group was higher than that in the before-COVID group (1.82% vs. 1.50%, difference: 0.31% [0.30 to 0.33]; adjusted odds ratio: 1.22 [1.18 to 1.25]). The excess in-hospital mortality rate of the after-COVID in the lowest quartile group of county income tax was significantly higher than that in the highest quartile group (difference-in-difference: 0.18% (0.14 to 0.23); P-for-interaction: < 0.01). @*Conclusion@#During the COVID-19 pandemic, there was excess in-hospital mortality among patients who visited EDs, and there were disparities in excess mortality depending on community socioeconomic positions.

Effects of Emergency Care-related Health Policies during the COVID-19 Pandemic in Korea:a Quasi-Experimental Study

Background@#The purpose of this study was to review the nationwide emergency care-related health policies during the coronavirus disease 2019 (COVID-19) pandemic disaster in Korea and to analyze the effects of the policies on the safety of patients who visit emergency departments (EDs) during this period. @*Methods@#This study is a quasi-experiment study. The study population was patients who visited all 402 EDs in Korea between December 31, 2019 and May 13, 2020, using the National Emergency Department Information System (NEDIS) database. The study period was classified into 5 phases according to the level of national crisis warning of infectious disease and the implementation of emergency care-related health policies, and all study phases were 27 days. The primary outcome was in-hospital mortality, and the secondary outcome was length of stay (LOS) in the ED during the COVID-19 outbreak. @*Results@#The number of ED visits during the study period was 2,636,341, and the in-hospital mortality rate was 1.4%. The number of ED visits decreased from 803,160 in phase 1 to 496,619 in phase 5 during the study period. For in-hospital mortality, the adjusted odds ratio (OR) (95% confidence interval) was 0.77 (0.74–0.79) in phase 5 compared to phase 3. Additionally, by subgroup, the ORs were 0.69 (0.57–0.83) for the patients with acute myocardial infarction and 0.76 (0.67–0.87) for severe trauma in phase 5 compared to phase 3. The ED LOS increased while the number of ED visits decreased as the COVID-19 pandemic progressed, and the ED LOS declined after policy implementation (beta coefficient: −5.3 [−6.5 to −4.2] minutes in phase 5 compared to phase 3). @*Conclusion@#Implementing appropriate emergency care policies in the COVID-19 pandemic would have contributed to improving the safety of all emergency patients and reducing inhospital mortality by preventing excessive deaths.

Analysis of the Impact of the Coronavirus Disease Epidemic on the Emergency Medical System in South Korea Using the Korean Triage and Acuity Scale

Purpose@#Severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), has spread worldwide. Global health systems, including emergency medical systems, are suffering from a lack of medical resources. Using a method for classifying patients visiting the emergency department (ED), we aimed to investigate trends in emergency medical system usage during the COVID-19 epidemic in Korea. @*Materials and Methods@#This retrospective observational study included patients who visited emergency medical institutions registered with the National Emergency Department Information System database from January 1, 2017 to May 31, 2020. The primary outcome was identification of changes in the distribution of patients visiting the ED according to the type of emergency medical institution. The secondary outcome was a detailed comparison of Korean Triage and Acuity Scale (KTAS) levels and patient distributions before and during the infectious disaster crisis period. @*Results@#Severe patients visited regional emergency centers (RECs) and local emergency centers (LECs) more frequently during the COVID-19 period, and disposition status warranting admission to the intensive care unit or resulting in death was more common in RECs and LECs during the COVID-19 period [RECs, before COVID-19: 300686 (6.3%), during COVID-19: 33548 (8.0%) (p<0.001); LECs, before COVID-19: 373593 (3.7%), during COVID-19: 38873 (4.5%) (p<0.001)]. @*Conclusion@#During the COVID-19 period, severe patients were shifted to advanced emergency medical institutions, and the KTAS better reflected severe patients. Patient distribution according to the stage of emergency medical institution improved, and validation of the KTAS triage increased more in RECs.

Association between the number of prehospital defibrillation attempts and neurologic outcomes in out-of-hospital cardiac arrest patients without on-scene return of spontaneous circulation

Objective@#Delivery of prehospital defibrillation for shockable rhythms by emergency medical service providers is crucial for successful resuscitation in out-of-hospital cardiac arrest (OHCA) patients. The optimal range of prehospital defibrillation attempts for refractory shockable rhythms is unknown. This study evaluated the association between the number of prehospital defibrillation attempts and neurologic outcomes in OHCA patients. @*Methods@#A retrospective observational study was conducted using the nationwide OHCA registry. Adult OHCA patients who were treated by emergency medical service providers due to presumed cardiac origin with initial shockable rhythm were enrolled from 2013 to 2016. The final analysis was performed on patients without on-scene return of spontaneous circulation. The number of prehospital defibrillation attempts was categorized as follows: 2–3, 4–5, and ≥6 attempts. The primary outcome was a good neurologic recovery at hospital discharge. Multivariate logistic regression analysis was performed to evaluate the association between neurologic outcomes and the number of prehospital defibrillation attempts. @*Results@#A total of 4,513 patients were included in the final analysis. The numbers of patients for whom 2–3, 4–5, and ≥6 defibrillation attempts were made were 2,720 (60.3%), 1,090 (24.2%), and 703 (15.5%), respectively. Poorer outcomes were associated with ≥6 defibrillation attempts: survival to hospital discharge (adjusted odds ratio, 0.38; 95% confidence interval, 0.21–0.65) and good neurologic recovery (adjusted odds ratio, 0.42; 95% confidence interval, 0.21–0.84). @*Conclusion@#Six or more prehospital defibrillation attempts were associated with poorer neurologic outcomes in OHCA patients with an initial shockable rhythm who were unresponsive to on-scene defibrillation and resuscitation.

Interaction Effects between COVID-19 Outbreak and Community Income Levels on Excess Mortality among Patients Visiting Emergency Departments

Background@#The objective of this study was to examine the effect of the coronavirus disease 2019 (COVID-19) outbreak on excess in-hospital mortality among patients who visited emergency departments (EDs) and to assess whether the excess mortality during the COVID-19 pandemic varies by community income level. @*Methods@#This is a cross-sectional study using the National Emergency Department Information System (NEDIS) database in Korea. The study population was defined as patients who visited all 402 EDs with medical conditions other than injuries between January 27 and May 31, 2020 (after-COVID) and for the corresponding time period in 2019 (before-COVID). The primary outcome was in-hospital mortality. The main exposure was the COVID-19 outbreak, and the interaction variable was county per capita income tax. We calculated the risk-adjusted in-hospital mortality rates by COVID-19 outbreak, as well as the difference-in-difference of risk-adjusted rates between the before-COVID and after-COVID groups according to the county income tax using a multilevel linear regression model with the interaction term. @*Results@#A total of 11,662,167 patients (6,765,717 in before-COVID and 4,896,450 in afterCOVID) were included in the study with a 1.6% crude in-hospital mortality rate. The riskadjusted mortality rate in the after-COVID group was higher than that in the before-COVID group (1.82% vs. 1.50%, difference: 0.31% [0.30 to 0.33]; adjusted odds ratio: 1.22 [1.18 to 1.25]). The excess in-hospital mortality rate of the after-COVID in the lowest quartile group of county income tax was significantly higher than that in the highest quartile group (difference-in-difference: 0.18% (0.14 to 0.23); P-for-interaction: < 0.01). @*Conclusion@#During the COVID-19 pandemic, there was excess in-hospital mortality among patients who visited EDs, and there were disparities in excess mortality depending on community socioeconomic positions.

Effects of Emergency Care-related Health Policies during the COVID-19 Pandemic in Korea:a Quasi-Experimental Study

Background@#The purpose of this study was to review the nationwide emergency care-related health policies during the coronavirus disease 2019 (COVID-19) pandemic disaster in Korea and to analyze the effects of the policies on the safety of patients who visit emergency departments (EDs) during this period. @*Methods@#This study is a quasi-experiment study. The study population was patients who visited all 402 EDs in Korea between December 31, 2019 and May 13, 2020, using the National Emergency Department Information System (NEDIS) database. The study period was classified into 5 phases according to the level of national crisis warning of infectious disease and the implementation of emergency care-related health policies, and all study phases were 27 days. The primary outcome was in-hospital mortality, and the secondary outcome was length of stay (LOS) in the ED during the COVID-19 outbreak. @*Results@#The number of ED visits during the study period was 2,636,341, and the in-hospital mortality rate was 1.4%. The number of ED visits decreased from 803,160 in phase 1 to 496,619 in phase 5 during the study period. For in-hospital mortality, the adjusted odds ratio (OR) (95% confidence interval) was 0.77 (0.74–0.79) in phase 5 compared to phase 3. Additionally, by subgroup, the ORs were 0.69 (0.57–0.83) for the patients with acute myocardial infarction and 0.76 (0.67–0.87) for severe trauma in phase 5 compared to phase 3. The ED LOS increased while the number of ED visits decreased as the COVID-19 pandemic progressed, and the ED LOS declined after policy implementation (beta coefficient: −5.3 [−6.5 to −4.2] minutes in phase 5 compared to phase 3). @*Conclusion@#Implementing appropriate emergency care policies in the COVID-19 pandemic would have contributed to improving the safety of all emergency patients and reducing inhospital mortality by preventing excessive deaths.

Low serum cholesterol level as a risk factor for out-of-hospital cardiac arrest: a case-control study

Objective@#We aimed to identify the association between low serum total cholesterol levels and the risk of out-of-hospital cardiac arrest (OHCA). @*Methods@#This case-control study was performed using datasets from the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES) project and the Korea National Health and Nutrition Examination Survey (KNHANES). Cases were defined as emergency medical service-treated adult patients who experienced OHCA with a presumed cardiac etiology from the CAPTURES project dataset. Four controls from the KNHANES dataset were matched to each case based on age, sex, and county. Multivariable conditional logistic regression analysis was conducted to evaluate the effect of total cholesterol levels on OHCA. @*Results@#A total of 607 matched case-control pairs were analyzed. We classified total cholesterol levels into six categories (<148, 148-166.9, 167-189.9, 190-215.9, 216.237.9, and ≥238 mg/dL) according to the distribution of total cholesterol levels in the KNHANES dataset. Subjects with a total cholesterol level of 167-189.9 mg/dL (25th.49th percentile of the KNHANES dataset) were used as the reference group. In both the adjusted models and sensitivity analysis, a total cholesterol level of <148 mg/dL was significantly associated with OHCA (adjusted odds ratio [95% confidence interval], 6.53 [4.47.9.56]). @*Conclusion@#We identified an association between very-low total cholesterol levels and an increased risk of OHCA in a large, community-based population. Future prospective studies are needed to better understand how a low lipid profile is associated with OHCA.

Development of a modified trauma and injury severity score to predict disability in acute trauma patients

Objective@#The Trauma and Injury Severity Score (TRISS) has been used to predict trauma patient mortality and to assess the quality of trauma care systems. The goal of this investigation was to develop a modified trauma-related injury severity score (termed the TRISS-D) for predicting disability in acute trauma patients. @*Methods@#We used data collected by emergency medical services and entered into the Korea Centers for Disease Control and Prevention severe trauma database. The TRISS-D was based on age category (0–14, 15–54, ≥55 years), the Revised Trauma Score, and the Injury Severity Score. The outcome measures were severe disability and worsening disability. Worsening disability was defined as a lower Glasgow Outcome Scale score at hospital discharge than before the traumatic incident. Two types of cases were examined: those with penetrating or blunt injuries (group 1) and those with severe head injuries (group 2). We assessed the discriminatory power of the TRISS-D by calculating the area under a receiver operating characteristic curve (AUROC). @*Results@#The database comprised 14,791 patients; overall, 3,757 (25%) had severe disability and 6,018 (41%) had worsening disability. For severe disability, the AUROC (95% confidence interval) for the TRISS-D was 0.948 (0.944–0.952) in group 1 and 0.950 (0.946–0.954) in group 2. The corresponding values for worsening disability were 0.810 (0.803–0.817) and 0.816 (0.809–0.823), respectively. @*Conclusion@#The TRISS-D showed excellent discriminatory power for severe disability and very good discriminatory power for worsening disability.

Development of a modified trauma and injury severity score to predict disability in acute trauma patients

Objective@#The Trauma and Injury Severity Score (TRISS) has been used to predict trauma patient mortality and to assess the quality of trauma care systems. The goal of this investigation was to develop a modified trauma-related injury severity score (termed the TRISS-D) for predicting disability in acute trauma patients. @*Methods@#We used data collected by emergency medical services and entered into the Korea Centers for Disease Control and Prevention severe trauma database. The TRISS-D was based on age category (0–14, 15–54, ≥55 years), the Revised Trauma Score, and the Injury Severity Score. The outcome measures were severe disability and worsening disability. Worsening disability was defined as a lower Glasgow Outcome Scale score at hospital discharge than before the traumatic incident. Two types of cases were examined: those with penetrating or blunt injuries (group 1) and those with severe head injuries (group 2). We assessed the discriminatory power of the TRISS-D by calculating the area under a receiver operating characteristic curve (AUROC). @*Results@#The database comprised 14,791 patients; overall, 3,757 (25%) had severe disability and 6,018 (41%) had worsening disability. For severe disability, the AUROC (95% confidence interval) for the TRISS-D was 0.948 (0.944–0.952) in group 1 and 0.950 (0.946–0.954) in group 2. The corresponding values for worsening disability were 0.810 (0.803–0.817) and 0.816 (0.809–0.823), respectively. @*Conclusion@#The TRISS-D showed excellent discriminatory power for severe disability and very good discriminatory power for worsening disability.

Epidemiology and Outcomes of Sports-Related Traumatic Brain Injury in Children

BACKGROUND: Traumatic brain injury (TBI) is one of the leading causes of pediatric disability that results in many emergency department visits. The risk of TBI is high while playing sports. The aim of this study was to examine the demographics and clinical characteristics of sports-related TBI. METHODS: We performed a multicenter observational study using the Emergency Department–Based Injury In-Depth Surveillance database in Korea. Patients aged 5 to 18 years old, who sustained unintentional, sports-related head injuries between January 2011 and December 2016 were included. The type of sports was the main variable of interest, and it was classified into 6 categories. The primary outcome was TBI, and the secondary outcome was intracranial injury and hospital admission. A multivariable logistic regression analysis was performed to calculate the adjusted odds ratios (aORs) with 95% confidence intervals for the outcomes by sports type. RESULTS: Of the 1,537,617 injured patients, 10,717 (0.7%) patients were included in the study. Most of the patients were male (87.5%), and the most prevalent sports type was field sports (51.2%). The proportion of TBI, intracranial injury, and admission were 15.7%, 1.2%, and 3.5%, respectively. The aORs of TBI, intracranial injury, and admission in bicycle and street sports compared to field sports were 1.77 (1.37–2.28), 4.99 (2.62–9.50), and 2.27 (1.42–3.61) respectively. CONCLUSION: This is the first nationwide epidemiologic study of pediatric sports-related TBI in Korea. The ratios of TBI, intracranial injury and admission were highest in bicycle and street sports. Prevention strategies for pediatric sports-related TBI can be developed according to sports types.