Effect of the human papillomavirus vaccine on the risk of genital warts: a nationwide cohort study of South Korean adolescent girls.

Objectives: The purpose of this study was to assess the effectiveness of human papillomavirus (HPV) vaccination administered to adolescent girls through South Korea's National Immunization Program. Methods: This retrospective cohort study included individuals who were 12 to 13 years old, whether vaccinated or unvaccinated, between July 2016 and December 2017. The incidence of genital warts (GWs) was monitored through 2021. Time-stratified hazard ratios (HRs) were estimated, adjusting for birth year, socioeconomic status, and the level of urbanization of the region, and were presented with 95% confidence intervals (CIs). Data were sourced from the Immunization Registry Integration System, linked with the National Health Information Database. Results: The study included 332,062 adolescent girls, with an average follow-up period of approximately 4.6 years. Except for the first year, the HRs for the vaccinated group were lower than those for the unvaccinated group. The HRs for specific cutoff years were as follows: year 2, 0.62 (95% CI, 0.31 to 1.13); year 3, 0.58 (95% CI, 0.35 to 0.96); and year 4 and beyond, 0.39 (95% CI, 0.28 to 0.52). Conclusion: Our findings indicate that HPV vaccination was associated with a reduction in the risk of GWs among adolescent girls. Notably, this reduction became significant as the incidence of GWs increased with age.

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. This paper quantifies the changes in healthcare utilization attributable to COVID-19 and the COVID-19 vaccination by sub-groups. Methods: An interrupted time series analysis was conducted to examine the impact of COVID-19 on healthcare utilization in South Korea from January 2016 to December 2022 using aggregated patient-level data from the national health insurance system that accounts for 99% of all healthcare services in South Korea. We applied negative binomial models adjusting for seasonality and serial correlation. Falsification tests were conducted to test the validity of breakpoints. Stratified analyses by type of healthcare services, age, sex, income level, health facility type, and avoidable/non-avoidable hospitalizations was performed, and we assessed differences in utilization trends between population groups across three phases of the pandemic. Findings: In early 2020, the COVID-19 pandemic caused a reduction in monthly volume of outpatient utilization by 15.7% [95% CI 13.3%-18.1%, p < 0.001] and inpatient utilization by 11.6% [10.1%-13.0%, p < 0.001]. Most utilization recovered and rebounded to pre-COVID-19 levels as of December 2022 although variations existed. We observed heterogeneity in the magnitude of relative changes in utilization across types of services, varying from a 42.7% [36.8%-48.0%, p < 0.001] decrease for pediatrics, a 23.4% [20.1%-26.5%%, p < 0.001] reduction in utilization of public health centers, and a 24.2% [21.2%-27.0%, p < 0.001] reduction in avoidable hospitalizations compared to the pre-pandemic period. Contrary to global trends, health utilization among the elderly population (65 and older) in South Korea saw only marginal reductions compared to other age groups. Similarly, Medicaid patients and lower income groups experienced a smaller reduction compared to higher income groups. Interpretation: The impact of the COVID-19 pandemic on healthcare utilization in South Korea was less pronounced compared to the global average. Utilization of vulnerable populations, including adults over 65 years old and lowest-income groups reduced less than other type of patients. Funding: No funding.

Risk of cancer, cardiovascular disease, thromboembolism, and mortality in patients with rheumatoid arthritis receiving Janus kinase inhibitors: a real-world retrospective observational study using Korean health insurance data.

OBJECTIVES: This study investigated whether Janus kinase inhibitors (JAKis) raise the risk of cardiovascular disease (CVD), venous thromboembolism (VTE), and cancer in patients with rheumatoid arthritis (RA). METHODS: We conducted a real-world retrospective observational study using data obtained from the Korean National Health Insurance Service database. Two data sets were analyzed: tumor necrosis factor inhibitor (TNFi)/JAKi-naive RA patients (set 1) and all RA patients who used TNFis or JAKis (set 2). The incidence rate ratios (IRRs) and hazard ratios (HRs) for acute myocardial infarction (AMI), stroke, cardiovascular (CV)-related mortality, major adverse cardiovascular events (MACE), VTE, arterial thromboembolism (ATE), cancer, and all-cause mortality were compared between the JAKi and TNFi groups. RESULTS: Set 1 included 1,596 RA patients (JAKi group: 645; TNFi group: 951), and set 2 included 11,765 RA patients (JAKi group: 2,498; TNFi group: 9,267). No adverse events (AEs) showed significantly higher IRRs in the JAKi groups than in the TNFi groups of sets 1 and 2. The HRs for MACE in the JAKi groups of sets 1 and 2 were 0.59 (95% confidence [CI], 0.35 to 0.99) and 0.80 (95% CI, 0.67 to 0.97), respectively. The JAKi group of set 2 showed a significantly higher risk of all-cause mortality (HR, 1.71; 95% CI, 1.32 to 2.20), but the other AEs did not demonstrate increased risks in the JAKi groups. CONCLUSIONS: In this study, JAKis did not increase the risk of AMI, stroke, CV-related mortality, MACE, VTE, ATE, or cancer in Korean RA patients relative to TNFis.

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. METHODS: Conditions of interest were selected from the US Vaccine Adverse Event Reporting System Table of Reportable Events and a recent report from a European consortium on vaccine surveillance. We used the National Health Insurance Service database in Korea to identify the monthly numbers of cases with these conditions. Data from January 2006 to June 2020 were included. Prediction models were constructed from the observed incidences using an autoregressive integrated moving average. We predicted the incidences of the conditions and their respective 95% confidence intervals (CIs) for January through December 2021. In addition, subgroup analysis for the expected vaccination population was conducted. RESULTS: Mean values (95% CIs) of the predicted monthly incidence of vasovagal syncope, anaphylaxis, brachial neuritis, acute disseminated encephalomyelitis, Bell's palsy, Guillain-Barré syndrome, encephalopathy, optic neuritis, transverse myelitis, immune thrombocytopenic purpura, and systemic lupus erythematosus in 2021 were 23.89 (19.81-27.98), 4.72 (3.83-5.61), 57.62 (51.37-63.88), 0.03 (0.01-0.04), 8.58 (7.90-9.26), 0.26 (0.18-0.34), 2.13 (1.42-2.83), 1.65 (1.17-2.13), 0.19 (0.14-0.25), 0.75 (0.61-0.90), and 3.40 (2.79-4.01) cases per 100,000 respectively. The majority of the conditions showed an increasing trend with seasonal variations in their incidences. CONCLUSION: We measured the incidence of a total of 11 conditions that could potentially be associated with VAEs to predict the monthly incidence in 2021. In Korea, conditions that could potentially be related to VAEs occur on a regular basis, and an increasing trend is observed with seasonality.

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. OBJECTIVES: This study investigated the relationships between nurse staffing level and survival after PCA in Korean hospitals using inpatient National Health Insurance (NHI) claim data. METHODS: The study used NHI claim data on patient and hospital characteristics for 2140 patients undergoing craniotomy or percutaneous angioplasty from January to December 2009. Because the information about nurse staffing in NHI claim data categorized nursing grade according to the nurse-to-bed ratio, the nurse staffing level was transformed from the nurse-to-patient ratio using the bed occupancy rate. The general ward and ICU nurse staffing levels were then categorized into major violation, violation, adherence, and major adherence according to the medical law standard. The association between nurse staffing level and survival after PCA was analyzed using logistic regression analyses with a generalized estimation model. RESULTS: The survival rate was higher for patients in hospitals with major adherence [odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.13-2.07] ICUs nurse staffing than for those in hospitals with adherence nurse staffing, and lower for patients in hospitals with violation (OR = 0.50, 95% CI = 0.26-0.93) or major violation (OR = 0.45, 95% CI = 0.21-0.97) general ward nurse staffing than for those in hospitals with adherence nurse staffing. Policies to ensure adherence to the medical law standard for nurse staffing levels is necessary to enhance the safety of patients experiencing PCA in Korea.

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. We examined between-period correlations for the age-standardized smoking prevalence at the district-level and investigated the district-level differences in smoking prevalence and income gaps between the two databases. RESULTS: The between-period correlation coefficients of smoking prevalence for both genders were 0.92-0.97 in NHSD and 0.58-0.69 in CHS, respectively. When using NHSD, we found significant income gaps in all districts for men and 244 districts for women. However, when CHS was analyzed, only 167 and 173 districts for men and women, respectively, showed significant income gaps. While correlation coefficients of district-level smoking prevalence from two databases were 0.87 for men and 0.85 for women, a relatively weak correlation between income gaps from the two databases was found. CONCLUSION: Based on two databases, income gaps in smoking prevalence were evident for nearly all districts of Korea. Because of the large sample size for each district, NHSD may provide stable district-level smoking prevalence and its income gap and thus should be considered as a valuable data source for monitoring district-level smoking prevalence and its socioeconomic inequality.

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. METHODS: District-level health care utilization and mortality data were obtained to estimate age-standardized CVD morbidity and mortality. The bivariate Pearson correlation was used to examine the linear relationship between district-level CVD morbidity and mortality Z-scores. Simple linear regression and multivariate analyses were conducted to investigate the associations of area characteristics with CVD morbidity, mortality, and discrepancies between morbidity and mortality. RESULTS: Substantial variation was found in CVD morbidity and mortality across the country, with 1074.9 excess CVD inpatients and 73.8 excess CVD deaths per 100,000 between the districts with the lowest and highest CVD morbidity and mortality, respectively. Higher rates of CVD admissions and deaths were clustered in the noncapital regions. A moderate geographic correlation between CVD morbidity and mortality was found (Pearson correlation coefficient = .62 for both genders). Neighborhood level indicators for socioeconomic disadvantages, undersupply of health care resources, and unhealthy behaviors were positively associated with CVD morbidity and mortality and the relative standing of CVD mortality vis-à-vis morbidity. CONCLUSIONS: Policy actions targeting life-course socioeconomic conditions, equitable distribution of health care resources, and behavioral risk factors may help reduce geographic differences in CVD morbidity and mortality in 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. We calculated the age-standardized overweight prevalence and its interquintile income gap at the district level. We examined the magnitudes of the between-period correlation for age-standardized overweight prevalence. The differences in overweight prevalence and its income gap between the NHSD and the CHS were also investigated. RESULTS: The age-adjusted mean BMI from the CHS was lower than those from the NHSD and the KNHANES. The magnitudes of the between-period correlation for overweight prevalence were greater in the NHSD compared to the CHS. We found that the district-level overweight prevalence in the NHSD were higher in all districts of Korea than in the CHS. The correlation coefficients for income gaps in overweight prevalence between the two databases were relatively low. In addition, when using the NHSD, the district-level income inequalities in overweight were clearer especially among women than the inequalities using the CHS. CONCLUSION: The relatively large sample size for each district and measured anthropometric data in the NHSD are more likely to contribute to valid and reliable measurement of overweight inequality at the district level in Korea.

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. It sorted the user's individual probability of stroke into five categories - normal, slightly high, high, risky, very risky, according to the five ranges of average probability of stroke in comparison to total population - less than 50 percentile, 50-70, 70-90, 90-99.9, more than 99.9 percentile, and constructed the personalized warning and lifestyle correction messages by each category. RESULTS: Risk factors in stroke risk model include the age, BMI, cholesterol, hypertension, diabetes, smoking status and intensity, physical activity, alcohol drinking, past history (hypertension, coronary heart disease) and family history (stroke, coronary heart disease). The AUC values of stroke risk prediction model from the external validation data set were 0.83 in men and 0.82 in women, which showed a high predictive power. The probability of stroke within 10 years for men in normal group (less than 50 percentile) was less than 3.92% and those in very risky group (top 0.01 percentile) was 66.2% and over. The women's probability of stroke within 10 years was less than 3.77% in normal group (less than 50 percentile) and 55.24% and over in very risky group. CONCLUSIONS: This study developed the stroke risk prediction model and the personalized warning and the lifestyle correction message based on the national health examination data and uploaded them to the personal health record service called My Health Bank in the health information website - Health iN. By doing so, it urged medical users to strengthen the motivation of health management and induced changes in their health behaviors.

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 qualification data, the General Health Screening data and the health insurance claims data were used. RESUTLS: Visiting rate to medical institution within one-year was 42.3%. Gender, age, family history of hypertension, smoking status, drinking frequency, insurance type, BMI, hypertension status, blood glucose level and LDL-cholesterol level were significant variables for visiting a medical institution. Of the study subjects who visited a medical institution, the antihypertensive prescription rate was 89.1%. Medication possession ratio was 70.9% and the rate of appropriate medication adherence was 60.6%. Age, family history of hypertension, smoking status, BMI level, hypertension level, blood glucose level, status, and LDL-cholesterol level were significant variables for the antihypertensive prescription and gender, age, family history of hypertension, smoking status, BMI, hypertension status, and the time of the first visit to a medical institution were significant variables for appropriate medication adherence. CONCLUSIONS: This study showed that the antihypertensive medication adherence in patients who were newly diagnosed with hypertension was not relatively high in Korea. National Health Insurance Service should support an environment in which medical institutions and those diagnosed with hypertension can fulfill their roles.

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. Overall agreement, sensitivity, specificity, and kappa values were calculated. Multiple logistic regression analysis was performed to identify factors associated with discrepancies and was adjusted for age, gender, insurance type, insurance contribution, residential area, and comorbidities. RESULTS: Agreement was highest between questionnaire data and claims data based on primary codes up to 1 year before the completion of self-reported questionnaires and was lowest for claims data based on primary and secondary codes up to 5 years before the completion of self-reported questionnaires. When comparing data based on primary codes up to 1 year before the completion of self-reported questionnaires, the overall agreement, sensitivity, specificity, and kappa values ranged from 93.2 to 98.8%, 26.2 to 84.3%, 95.7 to 99.6%, and 0.09 to 0.78, respectively. Agreement was excellent for hypertension and diabetes, fair to good for stroke and heart disease, and poor for pulmonary tuberculosis and dyslipidemia. Women, younger individuals, and employed individuals were most likely to under-report disease. CONCLUSIONS: Detailed patient characteristics that had an impact on information bias were identified through the differing levels of agreement.

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 0.99. The absolute difference between the LE of the two data was not more than 0.5 years, and did not exceed 0.3 years in gender specific results. The concordance correlation coefficients (CCC) between the crude mortality rates from NHID and the rates from KOSIS ranged 0.997-0.999 among the municipalities. For LE, the CCC between the NHID and KOSIS across the municipalities were 0.990 in 2004-2009 and 0.985 in 2010-2015 among men, and 0.952 in 2004-2009 and 0.914 in 2010-2015 among women, respectively. Overall, the NHID was a good source for monitoring mortality and LE across national, provincial, and municipal levels with the population representativeness of entire Korean population. The results of this study indicate that NHID may well contribute to the national health promotion policy as a part of the health and health equity monitoring system.

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. PARTICIPANTS: To construct the NHIS-HEALS database, a sample cohort was first selected from the 2002 and 2003 health screening participants, who were aged between 40 and 79 in 2002 and followed up through 2013. This cohort included 514 866 health screening participants who comprised a random selection of 10% of all health screening participants in 2002 and 2003. FINDINGS TO DATE: The age-standardised prevalence of anaemia, diabetes mellitus, hypertension, obesity, hypercholesterolaemia and abnormal urine protein were 9.8%, 8.2%, 35.6%, 2.7%, 14.2% and 2.0%, respectively. The age-standardised mortality rate for the first 2 years (through 2004) was 442.0 per 100 000 person-years, while the rate for 10 years (through 2012) was 865.9 per 100 000 person-years. The most common cause of death was malignant neoplasm in both sexes (364.1 per 100 000 person-years for men, 128.3 per 100 000 person-years for women). FUTURE PLANS: This database can be used to study the risk factors of non-communicable diseases and dental health problems, which are important health issues that have not yet been fully investigated. The cohort will be maintained and continuously updated by the NHIS.

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. DESIGN/PARTICIPANTS: Using claim data from the National Health Insurance Corporation, 263,664 patients aged 65years or older who underwent major orthopaedic surgeries (total hip arthroplasty [THA], total knee arthroplasty [TKA], or hip fracture surgery [HFS]) between 2008 and 2012 were included. RESULT: The prescription rate for VTE prophylaxis has increased from 62.4% in 2008 to 75.4% in 2012 (P<0.001). The prescription rate for new oral anticoagulants following THA and TKA has increased drastically since 2010, while that following HFS has not. Instead, prophylactic use of aspirin or low molecular weight heparin has increased in HFS cases. The rate of postoperative complications has significantly increased annually only in HFS: VTE (P=0.018) and brain haemorrhage or gastrointestinal bleeding (P=0.019). CONCLUSION: This result could suggest the need for more studies about the use of VTE prophylactic medicines following HFS.

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). BMI (kg/m2) was measured. Cox proportional hazards model hazard ratios were calculated after adjusting for confounders. RESULTS: During a mean follow-up period of 10.5 years, 454,546 men and 239,877 women died. U-shaped associations were observed regardless of diabetes status, sex, age, and smoking history. Optimal BMI (kg/m2) for the lowest mortality by group was 23.5-27.9 (normoglycemia), 25-27.9 (IFG), 25-29.4 (newly diagnosed diabetes), and 26.5-29.4 (prevalent diabetes). Higher optimal BMI by worsening diabetes status was more prominent in younger ages, especially in women. The relationship between worsening diabetes status and higher mortality was stronger with lower BMI, especially at younger ages. Given the same BMI, people with prevalent diabetes had higher mortality compared with those with newly diagnosed diabetes, and this was more striking in women than men. CONCLUSIONS: U-curve relationships existed regardless of diabetes status. Optimal BMI for lowest mortality became gradually higher with worsening diabetes for each sex and each age-group.

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/m2) in subjects over the age of 20. Age and sex standardization were used for all data. RESULTS: The KSSO released the 'Obesity Fact Sheet 2016' using the 2006-2015 NHIS Health Checkup database. The prevalence of obesity steadily increased from 28.7% in 2006 to 32.4% in 2015, and the prevalence of abdominal obesity also steadily increased from 18.4% in 2009 to 20.8% in 2015. The prevalence of class II obesity steadily increased from 2006 to 2015, such that the total prevalence was 4.8% in 2015 (5.6% in men and 4.0% in women). The highest prevalence of obesity was found in Jeju Island, while the lowest prevalence was found in Daegu City. The highest prevalence of abdominal obesity was also found in Jeju Island, while the lowest prevalence was found in Gwangju City. CONCLUSION: Based on the Obesity Fact Sheet 2016, a strategy for reducing the prevalence of obesity is needed, especially in Korean men.

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. The study population consisted of all participants in breast cancer screening from 2009 to 2014. Crude detection rate, positive predictive value and sensitivity and specificity of breast cancer screening and, incidence rate of interval cancer of the breast were calculated. RESULTS: The crude detection rate of breast cancer screening per 100,000 participants increased from 126.3 in 2009 to 182.1 in 2014. The positive predictive value of breast cancer screening per 100,000 positives increased from 741.2 in 2009 to 1,367.9 in 2014. The incidence rate of interval cancer of the breast per 100,000 negatives increased from 51.7 in 2009 to 76.3 in 2014. The sensitivities of screening for breast cancer were 74.6% in 2009 and 75.1% in 2014 and the specificities were 83.1% in 2009 and 85.7% in 2014. CONCLUSIONS: To increase the detection rate of breast cancer by breast cancer screening using mammography, the participation rate should be higher and an environment where accurate mammography and reading can be performed and reinforcement of quality control are required. To reduce the incidence rate of interval cancer of the breast, it will be necessary to educate women after their 20s to perform self-examination of the breast once a month regardless of participation in screening for breast cancer.

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. GDM+T was identified using the International Classification of Diseases-10th Revision (ICD-10) and prescription codes using Korea National Health Insurance (KNHI) claims. RESULTS: Approximately 0.39% of primiparas developed GDM+T. Compared to metabolically healthy normal weight (MHNW) women, both metabolically unhealthy normal weight (MUNW) and metabolically healthy obese (MHO) women had a significantly increased risk for developing GDM+T (odds ratio, OR: 9.53, 95% confidence interval, CI: 5.64-16.09 and OR: 3.30, 95% CI: 2.56-4.25, respectively). Specifically, MUNW individuals had a significantly higher risk of GDM+T when directly compared to MHO women even after adjusting for other GDM risk factors (OR: 2.92, 95% CI: 1.67-5.10). Furthermore, underweight women with metabolic syndrome showed a significantly increased frequency of GDM+T compared to MHNW subjects (OR: 8.87, 95% CI: 1.19-66.32). CONCLUSIONS: Pre-pregnant metabolic status is critical for development of GDM+T, regardless of their BMI. Therefore, intensive intervention for the components of metabolic syndrome may be helpful for the prevention of GDM+T even in low or normal weight women.