Identification of acute myocardial infarction and stroke events using the National Health Insurance Service database in Korea.

OBJECTIVES: The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review. METHODS: We first established a concept and definition of "hospitalization episode," taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms' accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm- identified events. RESULTS: We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively. CONCLUSIONS: We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea.

Uric Acid and Risk of Cardiovascular Disease and Mortality: A Longitudinal Cohort Study.

BACKGROUND: This study aimed to examine the association of serum uric acid levels with incident cardiovascular disease and mortality in Korean adults without gout. METHODS: This large longitudinal cohort study included adults aged > 19 years who had serum uric acid levels measured at least once at the National Health Insurance Service Ilsan Hospital from January 1, 2006 to December 31, 2015. Longitudinal data on person-level cardiovascular disease and cardiovascular mortality were linked to the National Health Insurance Service claims database and National Death Index. RESULTS: Among a total of 92,454 study participants with a median follow-up of 4.7 years, 7,670 (8.3%) composite events of cardiovascular disease or cardiovascular mortality were observed. Multivariable Cox proportional-hazards models revealed that each 1 mg/dL increment in uric acid level was associated with a 6% higher risk of composite outcomes. Compared with that for the uric acid level category of 4.0 to < 5.0 mg/dL, adjusted hazard ratios (95% confidence interval) for uric acid level categories of 5.0 to < 6.0, 6.0 to < 7.0, and ≥ 7.0 mg/dL were 1.10 (1.04-1.18), 1.20 (1.11-1.30), and 1.36 (1.25-1.47), respectively. In the secondary analyses for cardiovascular disease or cardiovascular mortality examined separately, a higher uric acid level was similarly associated with a higher risk of each adverse outcome. These associations were generally consistent across clinically relevant subgroups. CONCLUSION: A graded association was noted between serum uric acid levels and cardiovascular risk, suggesting that higher uric acid levels may adversely affect cardiovascular health and survival in individuals without gout.

The characteristic large-scale annual analysis by gender and age in heart failure patients: cohort for 10 years in Korea.

AIMS: The prevalence and incidence rate of heart failure (HF) continues to increase along with the aging of the population and the increase of ischaemic heart disease. The morbidity and mortality of HF are also on the rise in the industrialized countries; it can be a great public health problem. A detailed and accurate analysis of the demographical incidence and prevalence of HF is an important first step in predicting the occurrence of the disease in the future and proper preparing for prevention. Here, we aimed to analyse the annual prevalence and incidence of HF by gender and age using long-term national health insurance service data in the Republic of Korea. METHODS AND RESULTS: A total of 47 243 patients newly diagnosed with HF between 2006 and 2015 among nationally representative random subjects of 1 000 000 were included. The data of age and gender were analysed by year, and the total population information of the Ministry of Land, Infrastructure, and Transport of Korea was referred to compare the data of HF patients with the total population (2008-15). Over the decade from 2006 to 2015, the prevalence of HF patients showed tendency of increase (P < 0.001). The overall incidence rate was also gradually increasing (P < 0.001), but in women, it tended to decrease gradually. Women significantly accounted higher than the male group in incidence of HF over the period (54.6% vs. 45.4%, P < 0.001). The mean age at the time of diagnosis gradually increased (P = 0.002 for total, P = 0.001 for each gender). Total incidence was highest in 70s (27.22%), but males were the most in their 60s and females were in their 70s. Analysis of annual trend by age and gender distribution of HF incidence in men presented highest in the 50s-70s with a similar pattern annually, and the incidence is increasing more recently. Different from that of men, in the case of women, the incidence gradually increased with age in a similar annual pattern, peaking in their 70s and gradually decreasing in recent years. CONCLUSIONS: The prevalence and incidence of HF are gradually increasing. It increased rapidly in their 50s and older. It showed an increased incidence of HF especially in men between their 50s and 70s, and more observation and caution for the management of the risk factors may be needed to prevent HF in the male group.

Comprehensive Analysis of Iron Deficiency Anemia and Its Related Disorders in Premenopausal Women Based on a Propensity Score Matching Case Control Study Using National Health Insurance Service Database in Korea.

BACKGROUND: Menorrhagia is a common cause of iron deficiency anemia (IDA) in premenopausal women. However, the effects of menorrhagia on IDA in premenopausal women have been underestimated compared to those on other IDA-related disorders (IRDs) such as gastrointestinal malignancies (GIMs). To better understand the relationship between menorrhagia and IDA in premenopausal women, we analyzed the National Health Insurance Service-National Health Information Database (NHIS-NHID). METHODS: From 2005 to 2008, data about women between the age of 20 and 59 years were extracted from the NHIS-NHID to create a propensity score-matched case (IDA) and control group. The annual incidence of IDA was calculated per age group. A 10-year follow up of the study population was determined to detect IRDs in case and control groups. We compared the risk of detection (ROD) of IRDs, including GIM and gynecological disorders associated with menorrhagia - leiomyoma of uterus (LM) and adenomyosis (AM), in the case and the control group. RESULTS: From 2005 to 2008, women diagnosed with IDA (n = 535,249) and healthy women as a control group (n = 1,070,498) were identified from the NHIS-NHID. The annual incidence of IDA was 767.4 (2005), 948.7 (2006), 981.6 (2007), and 897.7 (2008) per 100,000 women. The age distribution of IDA was similar each year; IDA was common in women aged 30-39 years (36-37%) and 40-49 years (30-32%), and its incidence was significantly decreased in women aged 50-59 years (< 10%). The ROD of IRDs were significantly higher in the IDA group than in the control group (LM: 20.8% vs. 6.9%, AM: 5.6% vs. 1.6%, and GIM: 2.6% vs. 0.7%). The corresponding hazard ratios were 3.89 (95% confidence interval [CI], 3.85-3.93) for LM, 4.99 (95% CI, 4.90-5.09) for AM, and 3.43 (95% CI, 3.32-3.55) for GIM. The ROD of the IRDs varied; the ROD of LM in the IDA group increased with age and decreased in the age group 50-59 years. AM was more frequently detected in women with IDA aged 30-39 years and less in women older than 40 years. The frequency of GIM increased with age. CONCLUSION: In this study, we found that the gynecologic disease is the main cause of IDA in premenopausal women. Gynecological evaluations should be performed more actively in the clinic to prevent and control IDA and IRDs.

: Short-term effects of exposure to particulate matter on hospital admissions for asthma and chronic obstructive pulmonary disease.

We investigated the effects of particulate matter (PM) factors on hospitalization rates for asthma and chronic obstructive pulmonary disease (COPD). We obtained data on pollutants-PM10, PM2.5-in Seoul, South Korea. We also investigated data for asthma and COPD exacerbation that required hospitalization from 2006 to 2016. We used a time-stratified case-crossover design and generalized additive models with log transformation to assess adjusted risk, and conditional logistic regression was performed to analyze these data. Our study showed that PM10 and PM2.5, on different best lag days, were associated with increased risks of COPD or asthma hospitalization. The odds ratios (ORs) for each per-unit increase in PM10 and PM2.5 were higher in patients with male asthma (PM10: OR, 1.012; 95% confidence interval [CI], 1.008-1.016 and PM2.5: OR, 1.015; 95% CI, 1008-1.023), preschool asthma (PM10: OR, 1.015; 95% CI, 1.006-1.015 and PM2.5: OR, 1.015; 95% CI, 1.009-1.024), male COPD (PM10: OR, 1.012; 95% CI, 1.005-1.019 and PM2.5: OR, 1.013; 95% CI, 1.000-1.026), and senior COPD (PM10: OR, 1.016; 95% CI, 1.008-1.024 and PM2.5: OR, 1.022; 95% CI, 1.007-1.036). Increasing PM levels increased hospitalizations for asthma and COPD. Additionally, the consequences may be different according to age and sex, and PM2.5 may have a more significant effect on airway disease patients than PM10.

Transcatheter arterial embolization for gastrointestinal bleeding: Clinical outcomes and prognostic factors predicting mortality.

We evaluated clinical outcome and prognostic factors predicting mortality of transcatheter arterial embolization (TAE) for acute gastrointestinal (GI) bleeding. Fifty-nine patients (42 men, 17 women; mean age 66.1 ± 17.0) who underwent 59 TAE procedures for GI bleeding during 2013-2018 were retrospectively evaluated. Clinical outcomes included technical success, adverse events, and rebleeding and mortality rate within 30 days. The technical success rate was 100%. Angiography showed contrast extravasation in 41 (69.5%) patients and indirect signs of bleeding in 16 (27.1%) patients. Two (3.4%) patients underwent prophylactic embolization. TAE-related adverse events occurred in 7 (11.9%) patients; adverse events were more common for mid GI or lower GI bleeding than for upper GI bleeding (22.6% vs 0%, P = 0.007). Rebleeding within 30 days was observed in 22 (37.3%) patients after TAE. Coagulopathy was a prognostic factor for rebleeding (odds ratio [OR] = 3.53, 95% confidence interval 1.07-11.67, P = .038). Mortality within 30 days occurred in 11 (18.6%) patients. Coagulopathy (OR = 24, 95% confidence interval 2.56-225.32, P = .005) was an independent prognostic factor for mortality within 30 days. TAE is an effective, safe, and potentially lifesaving procedure for GI bleeding. If possible, coagulopathy should be corrected before TAE as it may reduce rebleeding and mortality.

Short-term effects of exposure to particulate matter and air pollution on hospital admissions for asthma and chronic obstructive pulmonary disease in Gyeonggi-do, South Korea, 2007-2018.

OBJECTIVES: Research is lacking on the impacts of exposure to particulate matter (PM) and air pollution on patients with chronic obstructive pulmonary disease (COPD) or asthma. Therefore, we investigate the effects of various air pollution factors on hospitalization for asthma and COPD. METHODS: We obtained data on pollutants-PM10, PM2.5, carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2)-in Gyeonggi-do, South Korea. We also extracted data from Korean National Health Insurance records and investigated asthma and COPD attacks that required hospitalization from January 2007 through February 2018. We used generalized additive models with Poisson distribution and log transformation to calculate adjusted risk. A time-stratified case-crossover design was used, and conditional logistic regression was performed to analyze these data. RESULTS: Per-unit increases in concentrations of PM10, PM2.5, SO2, NO2, CO, and O3 on different best lag days were associated with increased risks for hospital admission for COPD and asthma. SO2 had the strongest effect on hospital admission for asthma (odds ratio [OR], 1.535; 95 % confidence interval [CI], 1.450-1.619). SO2 also had the strongest effect on hospital admission for COPD (OR, 1.659; 95 % CI, 1.541-1.786). Subgroup analyses showed that these relationships were stronger in seniors (≥ 65 years old) and women with asthma than in men and nonseniors with COPD. CONCLUSIONS: Short-term exposure to PM10, PM2.5, CO, O3, NO2, and SO2 may result in hospitalization for asthma and COPD. Of these pollutants, SO2 has the strongest effects. Therefore, patients with COPD and asthma should be cautioned against performing outdoor activities when SO2 levels are high.

Risk for metabolic syndrome in the population with visceral fat area measured by bioelectrical impedance analysis.

BACKGROUND/AIMS: To investigate whether visceral fat area (VFA) measured by bioelectric impedance analysis (BIA) was associated with metabolic syndrome in subjects with and without obesity. METHODS: A total 23,202 participants who underwent medical check-ups were assessed. Participants were stratified by body mass index (BMI) and VFA. We evaluated six different groups for metabolic syndrome: Group 1 (normal weight and low VFA), Group 2 (normal weight and high VFA), Group 3 (overweight and low VFA), Group 4 (overweight and high VFA), Group 5 (obesity and low VFA), and Group 6 (obesity and high VFA). RESULTS: Metabolic syndrome traits and metabolic syndrome were significantly more prevalent in the high-VFA (≥ 100 cm2 ) subgroup in each BMI group. Adjusted logistic regression analyses revealed that the odds ratio for metabolic syndrome compared with Group 1 was the highest in Group 6 (24.53; 95% confidence interval [CI], 21.77 to 27.64). Notably, the odds ratio of Group 2 was higher than that of Group 3 (2.92; 95% CI, 2.30 to 3.69 vs. 2.57; 95% CI, 2.23 to 2.97). CONCLUSION: Our study demonstrates that the combination of BMI assessment and VFA determination by BIA may be a useful method for predicting the risk of metabolic syndrome. The VFA by BIA may be a useful target for interventions to improve metabolic syndrome.

Incidence, Comorbidity, and Mortality of Primary Congenital Glaucoma in Korea from 2001 to 2015: A Nationwide Population-based Study.

PURPOSE: To report incidence rates of primary congenital glaucoma in Korea and evaluate comorbidity and mortality from 2001 to 2015. METHODS: This study is a nationwide and retrospective population-based study. We used claims data from the Korean National Health Insurance Service database between 2001 and 2015. Data for all patients diagnosed with primary congenital glaucoma were retrieved using the Korean Electronic Data Interchange and Korean Standard Classification of Diseases-6 codes. RESULTS: The number of patients with primary congenital glaucoma between 2001 and 2015 was 776, of which 437 were male (56.31%) and 339 were female (43.69%). The annual prevalence demonstrated a general decreasing trend since 2011, but this was not significant. Over the total survey period, the incidence rate was 11.0 per 100,000 births, with 12.0 cases among males and 10.0 among females. The incidence according to age was 518 (68.78%) patients at age 0, 112 (13.66%) at 1 year, 70 (8.39%) at 2 years, and 76 (9.17%) at 3 years. Of the 776 patients diagnosed with primary congenital glaucoma in the study population, 27 died. The observed mortality per 100,000 people is about 10 times higher than that of the general infant and child population under the age of 4 years. Visual impairment was the most common accompanying disability, followed by brain lesion. CONCLUSIONS: Our study's estimates of the nationwide population-based incidence of primary congenital glaucoma in a Korean population will expand our understanding of the disease and allow healthcare systems to plan for primary congenital glaucoma.

Associated risk factors for psychological distress in patients with gastric epithelial neoplasm undergoing endoscopic submucosal dissection.

This study aimed to evaluate the psychological distress and associated risk factors for distress among patients with gastric epithelial neoplasm undergoing endoscopic submucosal dissection (ESD).A total of 91 patients treated with ESD for gastric epithelial neoplasm between May 2015 and June 2016 were prospectively enrolled. Sociodemographic factors, psychological distress, anxiety, depression, stress, and associated risk factors for psychological distress were evaluated the day before ESD.Twenty-six (28.6%) patients were identified as patients with psychological distress. The psychological distress group had a higher female ratio and more depression and anxiety symptoms than the non-distress group. Distress was also related to stress level. A multivariate analysis showed that unmarried status (odds ratio [OR], 4.94; 95% confidence interval [CI], 1.13-21.56, P = .034), anxiety (OR, 1.24; 95% CI, 1.12-1.39, P <.001), and stress (OR, 1.06; 95% CI, 1.01-1.12, P = .011) were associated with psychological distress.An unmarried status and a high level of anxiety and stress were associated with more psychological distress in patients undergoing gastric ESD. It could be helpful to screen and proactively monitor patients with such conditions before performing gastric ESD.

The Effect of Diagnosis-Related Group Payment System on Quality of Care in the Field of Obstetrics and Gynecology among Korean Tertiary Hospitals.

PURPOSE: To examine changes in clinical practice patterns following the introduction of diagnosis-related groups (DRGs) under the fee-for-service payment system in July 2013 among Korean tertiary hospitals and to evaluate its effect on the quality of hospital care. MATERIALS AND METHODS: Using the 2012-2014 administrative database from National Health Insurance Service claim data, we reviewed medical information for 160400 patients who underwent cesarean sections (C-secs), hysterectomies, or adnexectomies at 43 tertiary hospitals. We compared changes in several variables, including length of stay, spillover, readmission rate, and the number of simultaneous and emergency operations, from before to after introduction of the DRGs. RESULTS: DRGs significantly reduced the length of stay of patients undergoing C-secs, hysterectomies, and adnexectomies (8.0±6.9 vs. 6.0±2.3 days, 7.4±3.5 vs. 6.4±2.7 days, 6.3±3.6 vs. 6.2±4.0 days, respectively, all p<0.001). Readmission rates decreased after introduction of DRGs (2.13% vs. 1.19% for C-secs, 4.51% vs. 3.05% for hysterectomies, 4.77% vs. 2.65% for adnexectomies, all p<0.001). Spillover rates did not change. Simultaneous surgeries, such as colpopexy and transobturator-tape procedures, during hysterectomies decreased, while colporrhaphy during hysterectomies and adnexectomies or myomectomies during C-secs did not change. The number of emergency operations for hysterectomies and adnexectomies decreased. CONCLUSION: Implementation of DRGs in the field of obstetrics and gynecology among Korean tertiary hospitals led to reductions in the length of stay without increasing outpatient visits and readmission rates. The number of simultaneous surgeries requiring expensive operative instruments and emergency operations decreased after introduction of the DRGs.