COVID-19 and Neurodevelopmental Delays in Early Childhood: A Longitudinal Analysis of Developmental Outcomes in Korean Children.

This study employed a longitudinal analysis to evaluate the association between the coronavirus disease 2019 pandemic and neurodevelopment by analyzing over 1.8 million children from the Korean Developmental Screening Test for Infants and Children included in South Korea's National Health Screening Program. We compared the developmental outcomes in five age groups-9-17 months, 18-29 months, 30-41 months, 42-53 months, and 54-65 months-between the pre-pandemic (2018-2019) and pandemic (2020-2021) periods.

Impact of the Early COVID-19 Pandemic on Emergency Department Visits of Adult Cancer Patients With Fever or Respiratory Symptoms: A Korean Nationwide Population-Based Study, 2016-2020.

Background: We performed a nationwide analysis to evaluate the impact of the early coronavirus disease 2019 (COVID-19) pandemic on emergency department (ED) visits by adult cancer patients having COVID-like symptoms.

Methods: We analyzed the National Emergency Department Information System (NEDIS) data on ED visits by adult cancer patients who presented with chief complaints of fever or respiratory symptoms (FRS) indicative of COVID-19, from 2016 to 2020. An interrupted time series analysis with a quasi-Poisson regression model was performed, adjusting for seasonality and time, to evaluate whether underlying trends for monthly ED visits and the in-hospital mortality rate (%) per month changed with the pandemic among these patients.

Impact of the early phase of the COVID-19 pandemic on emergency department-to-intensive care unit admissions in Korea: an interrupted time-series analysis.

Background: The coronavirus disease 2019 (COVID-19) pandemic resulted in significant disruptions to critical care systems globally. However, research on the impact of the COVID-19 pandemic on intensive care unit (ICU) admissions via the emergency department (ED) is limited. Therefore, this study evaluated the changes in the number of ED-to-ICU admissions and clinical outcomes in the periods before and during the pandemic.

Risk factors for critical COVID-19 illness during Delta- and Omicron-predominant period in Korea; using K-COV-N cohort in the National health insurance service.

Background: This study evaluated the clinical characteristics of patients with COVID-19 in Korea, and examined the relationship between severe COVID-19 cases and underlying health conditions during the Delta (September 20, 2021 to December 4, 2021) and the Omicron (February 20, 2022 to March 31, 2022) predominant period.

Methods: This study assessed the association between critical COVID-19 illness and various risk factors, including a variety of underlying health conditions, using multiple logistic regression models based on the K-COV-N cohort, a nationwide data of confirmed COVID-19 cases linked with COVID-19 vaccination status and the National Health Insurance claim information.

Results: We analyzed 137,532 and 8,294,249 cases of COVID-19 infection during the Delta and the Omicron variant dominant periods, respectively.

Magnitude and Duration of Serum Neutralizing Antibody Titers Induced by a Third mRNA COVID-19 Vaccination against Omicron BA.1 in Older Individuals.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant (B.1.1.

Incidence, Severity, and Mortality of Influenza During 2010-2020 in Korea: A Nationwide Study Based on the Population-Based National Health Insurance Service Database.

Background: The epidemiology of influenza is commonly used to understand and establish relevant health policies for emerging respiratory infections, including coronavirus disease 2019 (COVID-19). However, Korea has no confirmed nationwide data on influenza incidence, severity, and mortality rate.

Methods: We conducted a cross-sectional study to obtain epidemic data on influenza at the national level using National Health Insurance claims data during 2010 to 2020.

Operation of national coordinating service for interhospital transfer from emergency departments: experience and implications from Korea.

Background: Since 2014, Korea has been operating the National Emergency Medical Situation Room (NEMSR) to provide regional emergency departments (EDs) with coordination services for the interhospital transfer of critically ill patients. The present study aimed to describe the NEMSR's experience and interhospital transfer pattern from EDs nationwide, and investigate the factors related to delayed transfers or transfers that could not be arranged by the NEMSR.

Methods: This study was a retrospective cross-sectional analysis of the NEMSR's coordination registry from 2017 to 2019.

Changing Features of Liver Injury in COVID-19 Patients: Impact of Infection with the SARS-CoV-2 Delta (B.1.617.2) Variants.

Background: There is growing evidence that abnormal liver function tests (LFTs) are common in patients with coronavirus disease 2019 (COVID-19). However, it is not known whether viral involvement in the liver differs according to the strain. We investigated the impact on liver injury in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta (B.

Semiconductor Work, Leukemia, and Cancer Risk: A Systematic Review and Meta-Analysis.

Background: With the development of the semiconductor industry over the past 60 years, various occupational diseases have been reported to coincide with rapid industrial growth. Among these occupational diseases, the association between semiconductor work and cancers, including leukemia, remains controversial. Therefore, this systematic review and meta-analysis assesses the associations between semiconductor work, leukemia, and cancer risk.

Patient and hospital characteristics predict prolonged emergency department length of stay and in-hospital mortality: a nationwide analysis in Korea.

Background: Prolonged emergency department length of stay (EDLOS) in critically ill patients leads to increased mortality. This nationwide study investigated patient and hospital characteristics associated with prolonged EDLOS and in-hospital mortality in adult patients admitted from the emergency department (ED) to the intensive care unit (ICU).

Methods: We conducted a retrospective cohort study using data from the National Emergency Department Information System.

Biological Assessment of Potential Exposure to Occupational Substances in Current Semiconductor Workers with at Least 5 Years of Employment.

Background: this study aimed to conduct a biological assessment of the potential exposure to carcinogenic substances in current semiconductor workers.

Methods: A cross-sectional study was conducted on 306 semiconductor workers. The assessed biomarkers were as follows: (benzene) urine S-phenylmercapturic, trans,trans-muconic acid, blood benzene; (trichloroethylene) urine trichloroacetic acid; (2-ethoxyethanol) 2-ethoxyacetic acid; (arsine) urine arsenic3+, arsenic5+, monomethylarsonic, dimethylarsinic acid, arsenobetaine; (shift work) 6-hydroxymelatonin; (smoking) cotinine, and (radiation).

Factors Related to Anxiety and Depression Among Adolescents During COVID-19: A Web-Based Cross-Sectional Survey.

Background: The coronavirus disease 2019 (COVID-19) outbreak and subsequent disease-containment measures (such as school closures) significantly affected the lives of adolescents. We evaluated the mental-health status and factors associated with anxiety and depression among South Korean adolescents.

Methods: A nationwide online survey was conducted to evaluate the mental-health status of South Korean adolescents during the COVID-19 pandemic.

Health Status, Health-Related Factors and Work Environment in Korean Semiconductor Workers between 1984-2012: A Qualitative Study and a Cross-Sectional Study.

Background: The environment of semiconductor facilities and exposure status has undergone changes. To identify changes in the work environment, health status, and risk factors, a qualitative and cross-sectional study was conducted.

Methods: For the qualitative study, 38 current and retired workers who worked for at least 10-years were studied; for the cross-sectional study, 306 current workers who worked for at least 5-years based on JEM strata from Samsung Electronics were selected.

The association between greenness exposure and COVID-19 incidence in South Korea: An ecological study.

Background: The rapid spread of COVID-19 has caused an emergency situation worldwide. Investigating the association between environmental characteristics and COVID-19 incidence can be of the occurrence and transmission. The objective of this study was to evaluate the association between greenness exposure and COVID-19 cases at the district levels in South Korea.

Booster BNT162b2 COVID-19 Vaccination Increases Neutralizing Antibody Titers Against the SARS-CoV-2 Omicron Variant in Both Young and Elderly Adults.

Concerns about the effectiveness of current vaccines against the rapidly spreading severe acute respiratory syndrome-coronavirus-2 omicron (B.1.1.

Predictors of the Development of Mental Disorders in Hospitalized COVID-19 Patients without Previous Psychiatric History: A Single-Center Retrospective Study in South Korea.

The objective of this study was to investigate the predictors for new-onset mental disorders among patients with mild to moderate COVID-19 illness during hospitalization. A retrospective cohort study was performed in patients with confirmed COVID-19 admitted to a nationally designated hospital between 1 February and 30 June 2020. Demographic, clinical, psychological assessments, and psychiatric outcomes were obtained from electronic medical record review.

Comparison of Complications after Coronavirus Disease and Seasonal Influenza, South Korea.

We conducted a retrospective cohort study using claims data to determine the number and types of complications from coronavirus disease (COVID-19) that patients experience and which patients are more vulnerable to those complications compared with complications in patients with influenza. Among the cohort, 19.6% of COVID-19 patients and 28.

Clinical Characteristics of 40 Patients Infected With the SARS-CoV-2 Omicron Variant in Korea.

Since severe acute respiratory syndrome-coronavirus-2 variant B.1.1.

The Use of Personal Protective Equipment among Frontline Nurses in a Nationally Designated COVID-19 Hospital during the Pandemic.

Background: The appropriate use of personal protective equipment (PPE) can significantly reduce the risk of infection associated with caring for patients. This study aimed to investigate the knowledge, awareness, and behaviors related to the PPE usage among frontline nurses in a nationally designated coronavirus disease 2019 (COVID-19) hospital during the COVID-19 pandemic.

Materials And Methods: The study was performed in two phases: (1) a questionnaire survey to assess the knowledge, awareness, and behaviors related to PPE use, and (2) in-depth personal interviews to elaborate the survey findings.