All-Cause and Cause-Specific Mortality Attributable to Seasonal Influenza: A Nationwide Matched Cohort Study.

Background: Although influenza poses substantial mortality burden, most studies have estimated excess mortality using time-aggregated data. Here, we estimated mortality risk and population attributable fraction (PAF) attributed to seasonal influenza using individual-level data from a nationwide matched cohort.

Methods: Individuals with influenza during four consecutive influenza seasons (2013-2017) (n = 5,497,812) and 1:4 age- and sex-matched individuals without influenza (n = 20,990,683) were identified from a national health insurance database.

Long-Term Ambient Air Pollution Exposures and Brain Imaging Markers in Korean Adults: The Environmental Pollution-Induced Neurological EFfects (EPINEF) Study.

Background: Only a limited number of neuroimaging studies have explored the effects of ambient air pollution in adults. The prior studies have investigated only cortical volume, and they have reported mixed findings, particularly for gray matter. Furthermore, the association between nitrogen dioxide () and neuroimaging markers has been little studied in adults.

Association between exposure to polycyclic aromatic hydrocarbons and brain cortical thinning: The Environmental Pollution-Induced Neurological EFfects (EPINEF) study.

Background: Although some studies have suggested that exposure to polycyclic aromatic hydrocarbons (PAHs) induces neurodevelopmental disturbances in children and neurodegeneration in animals, the neurotoxic effect of PAH exposure is unclear in adults. The aim was to examine the associations of PAH exposure with brain structure and neuropsychological function in adults without known neurological diseases.

Methods: This study included 421 men and 528 women dwelling in four cities in the Republic of Korea.

Correction: Big data and analysis of risk factors for gallbladder disease in the young generation of Korea.

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

Big data and analysis of risk factors for gallbladder disease in the young generation of Korea.

Background/purpose: Few studies have examined the risk factors for gallbladder (GB) disease in young adults. This study aimed to evaluate risk factors for GB disease in young adults based on big data in Korea.

Methods: All participants underwent routine checkup at the Korea Medical Institute from June 2014 to May 2015.

Cost-Effectiveness of Rivaroxaban Compared to Warfarin for Stroke Prevention in Atrial Fibrillation.

Background And Objectives: Rivaroxaban is noninferior to warfarin for preventing stroke or systemic embolism in patients with high-risk atrial fibrillation (AF) and is associated with a lower rate of intracranial hemorrhage (ICH). We assessed the cost-effectiveness of rivaroxaban compared to adjusted-dose warfarin for the prevention of stroke in patients with nonvalvular AF.

Methods: We built a Markov model using the Korean Health Insurance Review & Assessment Service database.

Prediction Models of Cognitive Trajectories in Patients with Nonamnestic Mild Cognitive Impairment.

To evaluate prediction models of cognitive trajectories in patients with nonamnestic mild cognitive impairment (naMCI) using group-based trajectory analysis, we evaluated 121 patients with naMCI who underwent at least their first three yearly assessments. Group-based trajectory models were used to classify cognitive trajectories based on Clinical Dementia Rating Sum of Boxes scores over four years in patients with naMCI. A total of 22 patients (18.

Effect of Socioeconomic Status and Underlying Disease on the Association between Ambient Temperature and Ischemic Stroke.

Purpose: Inconsistent findings have been reported regarding the effect of ambient temperature on ischemic stroke. Furthermore, little is known about how underlying disease and low socioeconomic status influence the association. We, therefore, investigated the relationship between ambient temperature and emergency department (ED) visits for ischemic stroke, and aimed to identify susceptible populations.

Short-term Effects of Ambient Air Pollution on Emergency Department Visits for Asthma: An Assessment of Effect Modification by Prior Allergic Disease History.

Objectives: The goal of this study was to investigate the short-term effect of ambient air pollution on emergency department (ED) visits in Seoul for asthma according to patients' prior history of allergic diseases.

Methods: Data on ED visits from 2005 to 2009 were obtained from the Health Insurance Review and Assessment Service. To evaluate the risk of ED visits for asthma related to ambient air pollutants (carbon monoxide [CO], nitrogen dioxide [NO], ozone [O], sulfur dioxide [SO], and particulate matter with an aerodynamic diameter <10 μm [PM]), a generalized additive model with a Poisson distribution was used; a single-lag model and a cumulative-effect model (average concentration over the previous 1-7 days) were also explored.

Changes in the Practice of Coronary Revascularization between 2006 and 2010 in the Republic of Korea.

Purpose: Evidence suggests that technological innovations and reimbursement schemes of the National Health Insurance Service may have impacted the management of coronary artery disease. Thus, we investigated changes in the practice patterns of coronary revascularization.

Materials And Methods: Revascularization and in-hospital mortality among Koreans ≥20 years old were identified from medical claims filed between 2006 and 2010.

Admission route and use of invasive procedures during hospitalization for acute myocardial infarction: analysis of 2007-2011 National Health Insurance database.

Objectives: The goal of this study was to investigate trends in admission to the emergency department and the use of invasive or surgical procedures during hospitalization for acute myocardial infarction (AMI) in Korea.

Methods: The National Health Insurance (NHI) claims database between 2007 and 2011 was used. We identified all admission claims that included codes from the tenth revision of the International Classification of Diseases beginning with I21 as the primary or secondary diagnosis.

Ambient ozone concentration and emergency department visits for panic attacks.

The effect of ambient air pollution on panic disorder in the general population has not yet been thoroughly elucidated, although the occurrence of panic disorder in workers exposed to organic solvents has been reported previously. We investigated the association of ambient air pollution with the risk of panic attack-related emergency department visits. Using health insurance claims, we collected data from emergency department visits for panic attacks in Seoul, Republic of Korea (2005-2009).

Air pollution and unintentional injury deaths in South Korea.

This study aimed to assess the association between exposure to air pollution and unintentional injury deaths in South Korea. Data regarding all unintentional injury deaths (17,566) in seven metropolitan cities from 2002 to 2008 were collected. Using a time-stratified case-crossover study, conditional logistic regression and subgroup analyses were performed after stratification by age, gender, and season.

Association between body mass index and cortical thickness: among elderly cognitively normal men and women.

Background: There is increasing evidence of a relationship between underweight or obesity and dementia risk. Several studies have investigated the relationship between body weight and brain atrophy, a pathological change preceding dementia, but their results are inconsistent. Therefore, we aimed to evaluate the relationship between body mass index (BMI) and cortical atrophy among cognitively normal participants.

Air pollution as a risk factor for depressive episode in patients with cardiovascular disease, diabetes mellitus, or asthma.

Background: There is currently insufficient evidence to confirm the effect of ambient air pollution on mental disorders, especially among susceptible populations. This study investigated the short-term effect of ambient air pollution on the risk of depressive episode and the effect modification across disease subpopulations.

Methods: Subjects who visited the emergency department (ED) for depressive episode from 2005 to 2009 (n=4985) in Seoul, Republic of Korea were identified from medical claims data.