The road to recovery: impact of COVID-19 on healthcare utilization in South Korea in 2016-2022 using an interrupted time-series analysis.

Background: The COVID-19 pandemic substantially disrupted healthcare utilization patterns, globally. South Korea had been praised widely in its efforts to contain the spread of the pandemic, which may have contributed to a significantly smaller reduction in healthcare utilization compared to neighboring countries. However, it remains unknown how the COVID-19 pandemic impacted utilization patterns across population sub-groups, particularly vulnerable patient groups in South Korea.

Estimating Baseline Incidence of Conditions Potentially Associated with Vaccine Adverse Events: a Call for Surveillance System Using the Korean National Health Insurance Claims Data.

Background: Vaccines against coronavirus disease 2019 (COVID-19) are raising concerns about vaccine safety, particularly in the context of large-scale immunization. To address public concerns, we measured the baseline incidence rates of major conditions potentially related to vaccine-related adverse events (VAEs). We aimed to provide a basis for evaluating VAEs and verifying causality.

Relationship between the legal nurse staffing standard and patient survival after perioperative cardiac arrest: A cross-sectional analysis of Korean administrative data.

Background: Nurses play crucial roles in cardiopulmonary resuscitation after perioperative cardiac arrest (PCA), and the level of nurse staffing is thought to influence the survival rate for cardiac arrest. However, no previous study has investigated the survival rate after PCA in Korea. In addition, nurse staffing levels in Korea are relatively low and their legal standard is not widely followed.

Effects of First Diagnosed Diabetes Mellitus on Medical Visits and Medication Adherence in Korea.

Background: The National Health Insurance Service (NHIS) conducted a screening test to detect chronic diseases such as hypertension and diabetes in Korea. This study evaluated the effects of health screening for DM on pharmacological treatment.

Methods: The data from qualification and the General Health Screening in 2012, the insurance claims of medical institutions from Jan 2009 to Dec 2014, and the diabetic case management program extracted from the NHIS administrative system were used.

Comparison of District-level Smoking Prevalence and Their Income Gaps from Two National Databases: the National Health Screening Database and the Community Health Survey in Korea, 2009-2014.

Background: We compared age-standardized prevalence of cigarette smoking and their income gaps at the district-level in Korea using the National Health Screening Database (NHSD) and the Community Health Survey (CHS).

Methods: Between 2009 and 2014, 39,049,485 subjects participating in the NHSD and 989,292 participants in the CHS were analyzed. The age-standardized prevalence of smoking and their interquintile income differences were calculated for 245 districts of Korea.

Prevalence of Overweight and Income Gaps in 245 Districts of Korea: Comparison Using the National Health Screening Database and the Community Health Survey, 2009-2014.

Background: We compared age-standardized overweight prevalence and their income gaps at the level of district in Korea using the National Health Screening Database (NHSD) and the Community Health Survey (CHS).

Methods: We analyzed 39,093,653 subjects in the NHSD and 926,580 individuals in the CHS between 2009 and 2014. For the comparison of body mass index (BMI) distributions, data from 26,100 subjects in the Korea National Health and Nutrition Examination Survey (KNHANES) were also analyzed.

Medical visits, antihypertensive prescriptions and medication adherence among newly diagnosed hypertensive patients in Korea.

Objectives: The objective of this study was to assess the antihypertensive medication adherence in patients who were newly diagnosed with hypertension in Korea.

Methods: Study subjects were diagnosed with hypertension for the first time by the General Health Screening in 2012 and were 65,919. As indices, visiting rate to medical institution, the antihypertensive prescription rate, medication possession ratio and the rate of appropriate medication adherence were used.

The development and implementation of stroke risk prediction model in National Health Insurance Service's personal health record.

Background And Objective: The purpose of this study was to build a 10-year stroke prediction model and categorize a probability of stroke using the Korean national health examination data. Then it intended to develop the algorithm to provide a personalized warning on the basis of each user's level of stroke risk and a lifestyle correction message about the stroke risk factors.

Methods: Subject to national health examinees in 2002-2003, the stroke prediction model identified when stroke was first diagnosed by following-up the cohort until 2013 and estimated a 10-year probability of stroke.

Geographic Variation in Morbidity and Mortality of Cerebrovascular Diseases in Korea during 2011-2015.

Background: Little is known about within-country variation in morbidity and mortality of cerebrovascular diseases (CVDs). Geographic differences in CVD morbidity and mortality have yet to be properly examined. This study examined geographic variation in morbidity and mortality of CVD, neighborhood factors for CVD morbidity and mortality, and the association between CVD morbidity and mortality across the 245 local districts in Korea during 2011-2015.

Level of Agreement and Factors Associated With Discrepancies Between Nationwide Medical History Questionnaires and Hospital Claims Data.

Objectives: The objectives of this study were to investigate the agreement between medical history questionnaire data and claims data and to identify the factors that were associated with discrepancies between these data types.

Methods: Data from self-reported questionnaires that assessed an individual's history of hypertension, diabetes mellitus, dyslipidemia, stroke, heart disease, and pulmonary tuberculosis were collected from a general health screening database for 2014. Data for these diseases were collected from a healthcare utilization claims database between 2009 and 2014.

Using the National Health Information Database of the National Health Insurance Service in Korea for Monitoring Mortality and Life Expectancy at National and Local Levels.

This study explores whether the National Health Information Database (NHID) can be used to monitor health status of entire population in Korea. We calculated the crude mortality rate and life expectancy (LE) at birth across the national, provincial, and municipal levels using the NHID eligibility database from 2004 to 2015, and compared the results with the corresponding values obtained from the Korean Statistical Information Service (KOSIS) of Statistics Korea. The study results showed that the ratio of crude mortality rate between the two data was 0.

Cohort profile: the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) in Korea.

Purpose: The National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) is a cohort of participants who participated in health screening programmes provided by the NHIS in the Republic of Korea. The NHIS constructed the NHIS-HEALS cohort database in 2015. The purpose of this cohort is to offer relevant and useful data for health researchers, especially in the field of non-communicable diseases and health risk factors, and policy-maker.

Trends of thromboprophylaxis and complications after major lower limb orthopaedic surgeries in Korea: National Health Insurance Claim Data.

Background: In Western countries, prophylaxis for venous thromboembolism (VTE) following major lower limb orthopaedic surgeries is recommended. However, that has not been the case in Asian countries, where the reported incidence of postoperative VTE has been low. The present study examined trends in VTE prophylaxis prescriptions and related complications following major lower limb orthopaedic surgeries in South Korea.

BMI and All-Cause Mortality in Normoglycemia, Impaired Fasting Glucose, Newly Diagnosed Diabetes, and Prevalent Diabetes: A Cohort Study.

Objective: This study examined associations between BMI and mortality in individuals with normoglycemia, impaired fasting glucose (IFG), newly diagnosed diabetes, and prevalent diabetes and identified BMI ranges associated with the lowest mortality in each group.

Research Design And Methods: A total of 12,815,006 adults were prospectively monitored until 2013. Diabetes status was defined as follows: normoglycemia (fasting glucose <100 mg/dL), IFG (100-125 mg/dL), newly diagnosed diabetes (≥126 mg/dL), and prevalent diabetes (self-reported).

Data Analytic Process of a Nationwide Population-Based Study on Obesity Using the National Health Information Database Presented by the National Health Insurance Service 2006-2015.

Background: In Korea, the prevalence of obesity has steadily increased, and the socioeconomic burden of obesity has increased along with it. In 2015, the National Health Insurance Service (NHIS) signed a memorandum of understanding with the Korean Society for the Study of Obesity (KSSO), providing limited open access to its databases so that the status of obesity and obesity management could be investigated.

Methods: Using NHIS databases, we analyzed nationwide population-based studies for obesity using the definition of obesity (body mass index ≥25 kg/m) in subjects over the age of 20.

Retrospective observation on contribution and limitations of screening for breast cancer with mammography in Korea: detection rate of breast cancer and incidence rate of interval cancer of the breast.

Background: The purpose of this study was to determine the benefits and limitations of screening for breast cancer using mammography.

Methods: Descriptive design with follow-up was used in the study. Data from breast cancer screening and health insurance claim data were used.

Influences of body size phenotype on the incidence of gestational diabetes needing prescription; analysis by Korea National Health Insurance (KNHI) claims and the National Health Screening Examination (NHSE) database.

Objectives: Although growing evidence has emphasized the pivotal role of metabolic status irrespective of body mass index (BMI), there has been no study to examine the association of body size phenotype with development of gestational diabetes that requires treatment with oral hypoglycemic agent or insulin (GDM+T) in primiparas.

Methods: Data from a total of 216,961 women who participated in the National Health Screening Examination (NHSE) between January 2007 and December 2011 and delivered their first babies within two years of the NHSE were analyzed. Body size phenotypes were classified according to body mass index (BMI) and the presence/absence of metabolic syndrome according to the results of the NHSE.

Development of a Korean Fracture Risk Score (KFRS) for Predicting Osteoporotic Fracture Risk: Analysis of Data from the Korean National Health Insurance Service.

Background: Asian-specific prediction models for estimating individual risk of osteoporotic fractures are rare. We developed a Korean fracture risk prediction model using clinical risk factors and assessed validity of the final model.

Methods: A total of 718,306 Korean men and women aged 50-90 years were followed for 7 years in a national system-based cohort study.

Prepregnancy Factors as Determinants of the Development of Diabetes Mellitus After First Pregnancy.

Context: The identification of modifiable factors at prepregnancy or early pregnancy as well as continued monitoring and management of these factors before and during pregnancy may reduce the incidence of diabetes mellitus (DM) among women, regardless of gestational diabetes mellitus (GDM) status.

Objective: This study aimed to identify prepregnancy factors for the development of DM in women with or without GDM in their first pregnancy.

Design And Participants: This retrospective, observational, cohort study included data for 53 109 women who underwent a National Health Screening Examination through the National Health Insurance Corporation between 2002 and 2003 and had their first delivery in 2004 with follow-up until 2012.

Association Between Smoking and Physician-Diagnosed Stroke and Myocardial Infarction in Male Adults in Korea.

To evaluate the association between smoking and physician-diagnosed stroke and myocardial infarction, this study used Community Health Survey data from 2009 on 92,082 males over the age of 30 years. Using multiple logistic regression, association index between smoking and physician-diagnosed stroke and myocardial infarction was calculated after adjusting the effects of age, hypertension, and diabetes. The odds ratios (95% confidence interval) of the physician-diagnosed stroke and myocardial infarction in the smoking group were 1.

Metabolic syndrome in the non-pregnant state is associated with the development of preeclampsia.

Background: The aim of this study was to investigate the association between metabolic syndrome in the non-pregnant state and the development of preeclampsia.

Methods: We enrolled 212,463 Korean women who had their first delivery between January, 2011 and December, 2012 and had undergone a national health screening examination through the National Health Insurance during the 1-2 years before their first delivery. Women who had hypertension in the non-pregnant state were excluded.