As the number of coronavirus disease 2019 (COVID-19) patients increased rapidly, the Korean government decided to pay most of the related medical expenses with finances from the National Health Insurance (NHI). We aimed to document changes in NHI medical expenses during the COVID-19 pandemic period. We also sought to compare how Japan and Taiwan, neighboring countries with NHI systems, responded to COVID-19 and to discuss policy implications.

Purpose: The purpose of this study was to investigate the age-related clinical features, risk factors, and prognoses of bacterial keratitis in Daejeon and Chungcheong provinces and the patterns and trends of fluoroquinolone antibiotic susceptibility. Methods: Medical records of 433 patients (433 eyes) who visited one of the five university hospitals in Daejeon and Chungcheong provinces and were diagnosed as culture-positive bacterial keratitis between January 2000 to December 2018 were reviewed retrospectively. The patients were divided into younger and older groups based on an age of 60 years. Predisposing factors, prognostic factors, treatment method, causative organisms, and susceptibility to fluoroquinolone were analyzed. Results: Two hundred seventy three males (63.0%) and 160 females (37.0%) were included. The most common risk factors in the younger group were contact lens wear (27.5%) and trauma and foreign body (27.0%). The most common risk factors in the older group were trauma and foreign body (30.5%). Staphylococcus species was the most common causative Gram-positive bacteria, regardless of age, and Pseudomonas species was the most common among Gram-negative bacteria. The older group tended to have more severe keratitis required more surgical treatment and had a worse visual outcome than the younger group (p < 0.05). As of 2011, the resistance to fluoroquinolone did not differ significantly between the groups (p > 0.05). Conclusions Bacterial keratitis in Daejeon and Chungcheong provinces indicated more severe clinical aspects and worse prognoses in older patients showing similar results from previous studies. Caution regarding trauma and foreign bodies and managing previous ocular disease is necessary for all age groups. Education regarding adequate contact lens care and hygiene is required for younger (<60 years) patients.

Purpose: The purpose of this study was to investigate the age-related clinical features, risk factors, and prognoses of bacterial keratitis in Daejeon and Chungcheong provinces and the patterns and trends of fluoroquinolone antibiotic susceptibility. Methods: Medical records of 433 patients (433 eyes) who visited one of the five university hospitals in Daejeon and Chungcheong provinces and were diagnosed as culture-positive bacterial keratitis between January 2000 to December 2018 were reviewed retrospectively. The patients were divided into younger and older groups based on an age of 60 years. Predisposing factors, prognostic factors, treatment method, causative organisms, and susceptibility to fluoroquinolone were analyzed. Results: Two hundred seventy three males (63.0%) and 160 females (37.0%) were included. The most common risk factors in the younger group were contact lens wear (27.5%) and trauma and foreign body (27.0%). The most common risk factors in the older group were trauma and foreign body (30.5%). Staphylococcus species was the most common causative Gram-positive bacteria, regardless of age, and Pseudomonas species was the most common among Gram-negative bacteria. The older group tended to have more severe keratitis required more surgical treatment and had a worse visual outcome than the younger group (p < 0.05). As of 2011, the resistance to fluoroquinolone did not differ significantly between the groups (p > 0.05). Conclusions Bacterial keratitis in Daejeon and Chungcheong provinces indicated more severe clinical aspects and worse prognoses in older patients showing similar results from previous studies. Caution regarding trauma and foreign bodies and managing previous ocular disease is necessary for all age groups. Education regarding adequate contact lens care and hygiene is required for younger (<60 years) patients.

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. MATERIALS AND METHODS: Using medical claims data, we identified ED visits for ischemic stroke during 2005–2009 in Seoul, Korea. We conducted piecewise linear regression analyses to find optimum ambient temperature thresholds in summer and winter, and estimated the relative risks (RR) and 95% confidence intervals (CI) per a 1℃ increase in temperature above/below the thresholds, adjusting for relative humidity, holidays, day of the week, and air pollutant levels. RESULTS: There were 63564 ED visits for ischemic stroke. In summer, the risk of ED visits for ischemic stroke was not significant, with the threshold at 26.8℃. However, the RRs were 1.055 (95% CI, 1.006–1.106) above 25.0℃ in medical aid beneficiaries and 1.044 (1.007–1.082) above 25.8℃ in patients with diabetes. In winter, the risk of ED visits for ischemic stroke significantly increased as the temperature decreased above the threshold at 7.2℃. This inverse association was significant also in patients with hypertension and diabetes mellitus above threshold temperatures. CONCLUSION: Ambient temperature increases above a threshold were positively associated with ED visits for ischemic stroke in patients with diabetes and medical aid beneficiaries in summer. In winter, temperature, to a point, and ischemic stroke visits were inversely associated.
Cardiovascular Diseases ; Diabetes Mellitus ; Emergency Service, Hospital ; Holidays ; Humans ; Humidity ; Hypertension ; Korea ; Linear Models ; Seoul ; Social Class* ; Stroke*

OBJECTIVES: A positive association between air pollution and both the incidence and prevalence of diabetes mellitus (DM) has been reported in some epidemiologic and animal studies, but little research has evaluated the relationship between air pollution and diabetic coma. Diabetic coma is an acute complication of DM caused by diabetic ketoacidosis or hyperosmolar hyperglycemic state, which is characterized by extreme hyperglycemia accompanied by coma. We conducted a time-series study with a generalized additive model using a distributed-lag non-linear model to assess the association between ambient air pollution (particulate matter less than 10 μm in aerodynamic diameter, nitrogen dioxide [NO2], sulfur dioxide, carbon monoxide, and ozone) and emergency department (ED) visits for DM with coma in Seoul, Korea from 2005 to 2009. METHODS: The ED data and medical records from the 3 years previous to each diabetic coma event were obtained from the Health Insurance Review and Assessment Service to examine the relationship with air pollutants. RESULTS: Overall, the adjusted relative risks (RRs) for an interquartile range (IQR) increment of NO2 was statistically significant at lag 1 (RR, 1.125; 95% confidence interval [CI], 1.039 to 1.219) in a single-lag model and both lag 0-1 (RR, 1.120; 95% CI, 1.028 to 1.219) and lag 0-3 (RR, 1.092; 95% CI, 1.005 to 1.186) in a cumulative-lag model. In a subgroup analysis, significant positive RRs were found for females for per-IQR increments of NO2 at cumulative lag 0-3 (RR, 1.149; 95% CI, 1.022 to 1.291). CONCLUSIONS: The results of our study suggest that ambient air pollution, specifically NO2, is associated with ED visits for diabetic coma.
Air Pollutants ; Air Pollution* ; Animals ; Carbon Monoxide ; Coma ; Diabetes Mellitus ; Diabetic Coma* ; Diabetic Ketoacidosis ; Emergencies* ; Emergency Service, Hospital* ; Female ; Humans ; Hyperglycemia ; Hyperglycemic Hyperosmolar Nonketotic Coma ; Incidence ; Insurance, Health ; Korea* ; Medical Records ; Nitrogen Dioxide ; Nonlinear Dynamics ; Prevalence ; Seoul* ; Sulfur Dioxide

Diverse somatic mutations have been reported to serve as cancer drivers. Recently, it has also been reported that epigenetic regulation is closely related to cancer development. However, the effect of epigenetic changes on cancer is still elusive. In this study, we analyzed DNA methylation data on colon cancer taken from The Caner Genome Atlas. We found that several promoters were significantly hypermethylated in colon cancer patients. Through clustering analysis of differentially methylated DNA regions, we were able to define subgroups of patients and observed clinical features associated with each subgroup. In addition, we analyzed the functional ontology of aberrantly methylated genes and identified the G-protein-coupled receptor signaling pathway as one of the major pathways affected epigenetically. In conclusion, our analysis shows the possibility of characterizing the clinical features of colon cancer subgroups based on DNA methylation patterns and provides lists of important genes and pathways possibly involved in colon cancer development.
Classification* ; Colon* ; Colonic Neoplasms* ; CpG Islands ; DNA ; DNA Methylation ; Epigenomics ; Genome ; Humans ; Methylation*

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 [NO₂], ozone [O₃], sulfur dioxide [SO₂], and particulate matter with an aerodynamic diameter <10 μm [PM₁₀]), 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. The percent increase and 95% confidence interval (CI) were calculated for each interquartile range (IQR) increment in the concentration of each air pollutant. Subgroup analyses were done by age, gender, the presence of allergic disease, and season. RESULTS: A total of 33 751 asthma attack cases were observed during the study period. The strongest association was a 9.6% increase (95% CI, 6.9% to 12.3%) in the risk of ED visits for asthma per IQR increase in O₃ concentration. IQR changes in NO₂ and PM₁₀ concentrations were also significantly associated with ED visits in the cumulative lag 7 model. Among patients with a prior history of allergic rhinitis or atopic dermatitis, the risk of ED visits for asthma per IQR increase in PM₁₀ concentration was higher (3.9%; 95% CI, 1.2% to 6.7%) than in patients with no such history. CONCLUSIONS: Ambient air pollutants were positively associated with ED visits for asthma, especially among subjects with a prior history of allergic rhinitis or atopic dermatitis.
Air Pollutants ; Air Pollution* ; Asthma* ; Dermatitis, Atopic ; Emergencies* ; Emergency Service, Hospital* ; Humans ; Insurance, Health ; Korea ; Nitrogen Dioxide ; Ozone ; Particulate Matter ; Rhinitis, Allergic ; Seasons ; Seoul ; Sulfur Dioxide

PURPOSE: The association between liver enzymes and death from external causes has not been examined. We investigated the association between serum aminotransferase levels and external-cause mortality in a large prospective cohort study. MATERIALS AND METHODS: A total of 142322 subjects of 35-59 years of age who completed baseline examinations in 1990 and 1992 were enrolled. Mortalities were identified using death certificates. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were categorized into quintiles. Sub-distribution hazards ratios and 95% confidence intervals (CIs) were estimated using a competing risks regression model in which deaths from other causes were treated as competing risks. RESULTS: Of 8808 deaths, 1111 (12.6%) were due to external causes. Injury accounted for 256 deaths, and suicide accounted for 255. After adjusting for covariates, elevated ALT and AST were significantly associated with an increased risk of all external-cause mortalities, as well as suicide and injury. Sub-distribution hazards ratios (95% CIs) of the highest versus the lowest quintiles of serum ALT and AST were, respectively, 1.57 (1.26-1.95) and 1.45 (1.20-1.76) for all external causes, 2.73 (1.68-4.46) and 1.75 (1.15-2.66) for suicide, and 1.79 (1.10-2.90) and 1.85 (1.21-2.82) for injury. The risk of external-cause mortality was also significantly higher in the fourth quintile of ALT (21.6-27.5 IU/L) than in its first quintile. CONCLUSION: Elevated aminotransferase levels, even within the normal range, were significantly associated with increased risk of all external-cause mortalities, including suicide, and injury.
Adult ; Alanine Transaminase/*blood/metabolism ; Aspartate Aminotransferases/*blood/metabolism ; Female ; Humans ; Male ; Middle Aged ; *Mortality ; *Population Surveillance ; Proportional Hazards Models ; Prospective Studies ; Republic of Korea/epidemiology ; Risk

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 > or =20 years old were identified from medical claims filed between 2006 and 2010. The age- and sex-standardized procedure rate per 100000 person-years was calculated directly from the distribution of the 2008 Korean population. RESULTS: The coronary revascularization rate increased from 116.1 (95% confidence interval, 114.9-117.2) in 2006 to 131.0 (129.9-132.1) in 2010. Compared to the rate ratios in 2006, the rate ratios for percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery in 2010 were 1.16 (1.15-1.17) and 0.80 (0.76-0.84), respectively. Among patients who received PCI, the percentage with drug-eluting stents increased from 89.1% in 2006 to 93.0% in 2010. In-hospital mortality rates from PCI significantly increased during the study period (p=0.03), whereas those from CABG significantly decreased (p=0.01). The in-hospital mortality rates for PCI and CABG were higher in elderly and female patients and at the lowest-volume hospitals. CONCLUSION: The annual volume of coronary revascularization continuously increased between 2006 and 2010 in Korea, although this trend differed according to procedure type. A high percentage of drug-eluting stent procedures and a high rate of in-hospital mortality at low-volume hospitals were noted.
Adult ; Aged ; Aged, 80 and over ; Coronary Artery Bypass/*statistics & numerical data/trends ; Coronary Artery Disease/*surgery ; Drug-Eluting Stents ; Female ; Hospital Mortality ; Humans ; Male ; Middle Aged ; Myocardial Revascularization/*methods/*trends ; Percutaneous Coronary Intervention/*statistics & numerical data/trends ; Republic of Korea/epidemiology

BACKGROUND/AIMS: The exercise ECG test (XECG) and computed tomography coronary angiography (CTCA) have been used widely in initial evaluations of coronary artery disease (CAD) in real-world practice. In this study, we compared the diagnostic power of CTCA and XECG, based on conventional coronary angiography (CCA). METHODS: We enrolled 589 consecutive patients retrospectively who had been examined with both XECG and CTCA for the evaluation of CAD in outpatient clinics. Significant stenosis was defined as more than 50% diameter stenosis. Triage to CCA and/or revascularization treatment (RT) by the results of XECG and CTCA and the diagnostic accuracy of both exams, based on CCA, were investigated. RESULTS: In the 589 patients, 107 (19%) were triaged to CCA for further evaluation; in 77 (12.8%) significant stenosis was detected on CCA. Also, 65 (11%) patients underwent RT. In the CTCA results, 120 patients had significant stenosis. Of them, 58 (48%) and 75 (62%) patients were triaged to RT and CCA, respectively. Based on the XECG, 115 positive patients were triaged to RT and CCA (23 [20%]/41 [35%]). Among 107 patients with CCA, the sensitivity, specificity, positive predictive value, and negative predictive value for significant stenosis on CCA of CTCA were 89.9%, 74.0%, 90.6%, and 71.4%, respectively, and those of XECG were 50.0, 67.9, 78.0, and 37.3, respectively. The kappa value of CCA and CTCA was 0.62 (p < 0.001) and that of CCA and XECG was 0.145 (p = 0.113). CONCLUSIONS: In real-world practice, CCA was decided on more frequently, based on CTCA. CTCA showed better diagnostic accuracy than XECG.
Ambulatory Care Facilities ; Constriction, Pathologic ; Coronary Angiography* ; Coronary Artery Disease ; Electrocardiography* ; Humans ; Retrospective Studies ; Sensitivity and Specificity ; Triage