Korean National Health Insurance System Research Articles

Cumulative exposure to impaired fasting glucose and future risk of type 2 diabetes mellitus

AimsThe status of metabolic abnormalities including impaired fasting glucose (IFG) can change over time, yet little is known about how exposure duration to IFG is related to diabetes risk. MethodsUsing nationally representative data from the Korean National Health Insurance system, 2,513,127 people who were free of diabetes and who received four consecutive annual health examinations commencing in 2006 or 2007 were followed up at the end of 2016. IFG was defined as fasting blood glucose levels of 100–125 mg/dL. Participants were classified numerically according to the cumulative number of IFG diagnoses. ResultsOver 4 years, 53% of the population participants remained normoglycemic, while 3% had persistent IFG and 44% had intermittent IFG. The risk of type 2 diabetes mellitus (DM) increased gradually with increasing IFG exposure score. Subjects with an IFG exposure score of 2, 3, or 4 had a 3.75- to 9.77-fold increased hazard ratio (HR) for incident diabetes (IFG exposure score 0 reference; score 2, HR 3.75, 95% confidence interval [CI] 3.67–3.83; score 3, HR 6.21, 95% CI 6.08–6.36; score 4, HR 9.77, 95% CI 9.53–10.02). ConclusionsCumulative IFG exposure was associated with a higher risk of type 2 DM in a dose–response fashion.

An increasing trend of the number of meniscus allograft transplantation in Korea.

Meniscus allograft transplantation (MAT) can be performed to treat symptomatic patients with meniscus-deficient knees. However, the current epidemiologic status of MAT is unknown in many countries, including Korea. This study aimed to investigate the national trends of MAT in Korea which covers MAT procedures by the Korean national health insurance system. Information from the national database was acquired through the Korean Health Insurance Review and Assessment Service (HIRA) from 2010 to 2017. All patients encoded as MAT were included. The total number of MATs and their incidence per 100,000 persons were determined, and the results were stratified by age and sex. The total number of MATs and their incidence per 100,000 persons per year were 369 and 0.77, respectively, in 2010, which increased to 826 and 1.72, respectively, in 2017. The number of MATs increased by 124% over 8years. The peaks for the total number of MATs and their incidence were seen in patients in their 20s in 2010, but in 2017, the peaks were observed in patients who were in their 40s. MAT was performed more frequently in males (61%) than in females (39%) over the study period. The total number of MATs and their incidence had increased by 124% between 2010 and 2017. The peak treatment age range for MAT changed from 20years of age in 2010 to 40years of age in 2017, and MAT was performed more frequently in males than in females. IV.

Update on association between exposure to renin-angiotensin-aldosterone system inhibitors and coronavirus disease 2019 in South Korea.

Background/AimsSince the onset of the coronavirus disease 2019 (COVID-19) pandemic, there have been concerns about the association between exposure to renin-angiotensin-aldosterone system (RAAS) inhibitors and the risk and severity of COVID-19.MethodsWe performed a case-control study that utilized up-to-date data on the South Korean population provided by the Korean National Health Insurance System. Of the 62,909 patients with hypertension or heart failure tested for COVID-19, there were 1,644 (2.6%) confirmed cases. After case-control matching, multivariable-adjusted conditional logistic regression analysis was performed.ResultsComparison between patients exposed to RAAS inhibitors and those not exposed to RAAS inhibitors revealed that the adjusted odds ratio (OR) and 95% confidence interval (CI) for COVID-19 infection and death were 0.981 (95% CI, 0.849 to 1.135) and 0.875 (95% CI, 0.548 to 1.396), respectively. Subgroup analysis for the major confounders, age and region of diagnosis, resulted in OR of 0.912 (95% CI, 0.751 to 1.108) and 0.942 (95% CI, 0.791 to 1.121), respectively.ConclusionsThe present study demonstrated no evidence of association between RAAS inhibitor exposure and risk and severity of COVID-19.

Association between living alone and incident type 2 diabetes among middle-aged individuals in Korea: a nationwide cohort study

We studied the association between living alone and the risk of incident type 2 diabetes in middle-aged individuals using nationwide cohort data from the Korean population. 11,686, 677 middle-aged individuals aged 40–64 years who underwent health examinations by the Korean National Health Insurance System between 2009 and 2012 were followed up until December 31, 2015. The hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards regression analysis. During the median follow-up duration of 5.6 years, 393,438 individuals developed type 2 diabetes. Living alone was significantly associated with incident type 2 diabetes in all adjusted models (HR 1.08; 95% CI 1.07–1.09 in model 4). Individuals who lived alone for < 1 year and 1–7 years were associated with increased HRs of 1.07 (1.04–1.09) and 1.08 (1.07–1.09). Living alone was associated with incident type 2 diabetes in all subgroups. The association was stronger in men than in women and younger individuals than in older individuals. Living alone, even for a short duration, may be an important factor in type 2 diabetes development. Better household conditions and appropriate support to one-person households may be needed to prevent type 2 diabetes.

Association of High-Density Lipoprotein Cholesterol Variability and the Risk of Developing Parkinson Disease.

To investigate the longitudinal association among high-density lipoprotein cholesterol (HDL-C) level, HDL-C variability, and the risk of developing Parkinson disease (PD). We conducted a nationwide, population-based cohort study. We included 382,391 patients aged ≥65 years who underwent at least 3 health examinations provided by the Korean National Health Insurance System from 2008 to 2013 and followed up until 2017. Individuals with a history of PD and missing values were excluded (n = 1,987). We assessed HDL-C variability using 3 indices, including variability independent of the mean (VIM). A multivariate-adjusted Cox proportional hazards regression analysis was performed. Among the 380,404 participants, 2,733 individuals were newly diagnosed with PD during a median follow-up period of 5 years. The lowest quartile (Q1) group of baseline HDL-C and mean HDL-C was associated with increased PD incidence as compared with the highest quartile (Q4) group (adjusted hazard ratio [aHR], 1.20; 95% confidence interval [CI], 1.08-1.34; and aHR, 1.16; 95% CI, 1.04-1.30, respectively). The Q4 group of HDL-C variability (VIM) was associated with increased PD incidence compared to the Q1 group (aHR, 1.19; 95% CI, 1.06-1.33). The group with the Q1 of baseline HDL-C and with the Q4 of HDL-C variability had the highest risk of PD incidence (aHR, 1.6; 95% CI, 1.31-1.96). Lower HDL-C level and greater HDL-C variability were associated with a higher incidence of PD.

Impact of waist circumference on the risk of vertebral fracture: A nationwide cohort study in South Korea.

Evidence on the association between abdominal obesity and vertebral fracture (VF) risk is limited. We examined the association of waist circumference (WC) and abdominal obesity with VF risk in 352,095 South Korean participants aged ≥40years who underwent health checkups between 2009 and 2012. Abdominal obesity was defined by WC ≥90cm in men and≥85cm in women according to the Asian-specific WC cutoff for abdominal obesity. Participants were a representative sample cohort of the Korean National Health Insurance System. The hazard ratios (HRs) and 95% CIs of VF development were determined using multivariable Cox proportional hazard regression analysis. During the 5.5years of follow-up, there were 2030 and 4968 new cases of VF in men and women, respectively. In men, those with abdominal obesity showed an elevated HR (1.11, 95% CI: 1.01-1.23) of incident VF than did those without abdominal obesity. In women, the HRs of VF increased in higher WC groups after adjusting for confounders (P for trend <0.001); the HR decreased in those with WC <75.0cm (HR: 0.81, 95% CI: 0.75-0.88) and increased in those with WC 85.0-89.9cm (HR: 1.12, 95% CI: 1.02-1.22), 90.0-94.9cm (HR: 1.19, 95% CI: 1.08-1.32), and≥95.0cm (HR: 1.27, 95% CI: 1.12-1.43) compared with those with WC 80.0-84.9cm. This association persisted after stratification by age in women. WC and abdominal obesity were positively associated with VF risk in women, and abdominal obesity was associated with VF risk even in men. The consideration of WC and controlling abdominal obesity may be helpful in reducing future VF risk.

Metabolic Syndrome Severity Score for Predicting Cardiovascular Events: A Nationwide Population-Based Study from Korea.

Background Recently, a metabolic syndrome severity score (MS score) using a dataset of the Korea National Health and Nutrition Examination Surveys has been developed. We aimed to determine whether the newly developed score is a significant predictor of cardiovascular (CV) events among the Korean population.Methods From the Korean National Health Insurance System, 2,541,364 (aged 40 to 59 years) subjects with no history of CV events (ischemic stroke or myocardial infarction [MI]), who underwent health examinations from 2009 to 2011 and were followed up until 2014 to 2017, were identified. Cox proportional hazard model was employed to investigate the association between MS score and CV events. Model performance of MS score for predicting CV events was compared to that of conventional metabolic syndrome diagnostic criteria (Adult Treatment Program III [ATP-III]) using the Akaike information criterion and the area under the receiver operating characteristic curve.Results Over a median follow-up of 6 years, 15,762 cases of CV events were reported. MS score at baseline showed a linear association with incident CV events. In the multivariable-adjusted model, the hazard ratios (95% confidence intervals) comparing the highest versus lowest quartiles of MS score were 1.48 (1.36 to 1.60) for MI and 1.89 (1.74 to 2.05) for stroke. Model fitness and performance of the MS score in predicting CV events were superior to those of ATP-III.Conclusion The newly developed age- and sex-specific continuous MS score for the Korean population is an independent predictor of ischemic stroke and MI in Korean middle-aged adults even after adjusting for confounding factors.

Changes in metabolic syndrome status affect the incidence of end-stage renal disease in the general population: a nationwide cohort study

Few studies have investigated the impact of a change in metabolic syndrome (MetS) components on clinical renal outcomes in the general population. Using nationally representative data from the Korean National Health Insurance System, 13,310,924 subjects who underwent two health examinations over 2 years and were free from end-stage renal disease (ESRD) from 2009 to 2012 were followed to the end of 2016. The subjects were divided into four groups according to the change in MetS components between the two visits over 2 years: no MetS (–/–), post-MetS (–/+), pre-MetS (+/–), and both MetS (+/+). After a median follow up of 5.11 years, 18,582 incident ESRD cases were identified. In the multivariate adjusted model, the hazard ratio (HR) and 95% confidence interval (CI) for the development of ESRD in the both-MetS (+/+) group compared with the no-MetS (–/–) group was 5.65 (95% CI, 5.42–5.89), which was independent of age, sex, and baseline estimated glomerular filtration rate. Additionally, the HR for the pre-MetS (+/–) group versus the no-MetS (–/–) group was 2.28 (2.15–2.42). In subgroup analysis according to renal function, the impact of a change in MetS on the incidence of ESRD was more pronounced in individuals with advanced renal dysfunction. Subjects with resolved MetS components had a decreased risk of ESRD, but not as low as those that never had MetS components. This provides evidence supporting the strategy of modulating MetS in the general population to prevent the development of ESRD.

Cohort profile: National Investigation of Birth Cohort in Korea study 2008 (NICKs-2008).

BackgroundAn adequate large-scale pediatric cohort based on nationwide administrative data is lacking in Korea.PurposeThis study established the National Investigation of Birth Cohort in Korea study 2008 (NICKs-2008) based on data from a nationwide population-based health screening program and data on healthcare utilization for children.MethodsThe NICKs-2008 study consisted of the Korean National Health Insurance System (NHIS) and the National Health Screening Program for Infants and Children (NHSPIC) databases comprising children born in 2008 (n=469,248) and 2009 (n=448,459) in the Republic of Korea. The NHIS database contains data on age, sex, residential area, income, healthcare utilization (International Classification of Diseases-10 codes, procedure codes, and drug classification codes), and healthcare providers. The NHSPIC consists of 7 screening rounds. These screening sessions comprised physical examination, developmental screening (rounds 2–7), a general health questionnaire, and age-specific anticipatory guidance.ResultsDuring the 10-year follow-up, 2,718 children (0.3%) died, including more boys than girls (hazard ratio, 1.145; P<0.001). A total of 848,048 children participated in at least 1 of the 7 rounds of the NHSPIC, while 96,046 participated in all 7 screening programs. A total of 823 infants (0.1%) weighed less than 1,000 g, 3,177 (0.4%) weighed 1,000–1,499 g, 37,166 (4.4%) weighed 1,500–2,499 g, 773,081 (91.4%) weighed 2,500–4,000 g, and 32,016 (5.1%) weighed over 4,000 g. There were 23,404 premature babies (5.5%) in 2008 compared to 23,368 (5.6%) in 2009. The developmental screening test indicated appropriate development in 95%–98% of children, follow-up requirements for 1%–4% of children, and recommendations for further evaluation for 1% of children.ConclusionThe NICKs-2008, which integrates data from the NHIS and NHSPIC databases, can be used to analyze disease onset prior to hospitalization based on information such as lifestyle, eating habits, and risk factors.

Association between height and the risk of primary brain malignancy in adults: a nationwide population-based cohort study.

BackgroundThe association between height and the risk of developing primary brain malignancy remains unclear. We evaluated the association between height and risk of primary brain malignancy based on a nationwide population-based database of Koreans.MethodsUsing data from the Korean National Health Insurance System cohort, 6 833 744 people over 20 years of age that underwent regular national health examination were followed from January 2009 until the end of 2017. We documented 4771 cases of primary brain malignancy based on an ICD-10 code of C71 during the median follow-up period of 7.30 years and 49 877 983 person-years.ResultsWhen dividing the population into quartiles of height for each age group and sex, people within the highest height quartile had a significantly higher risk of brain malignancy, compared to those within the lowest height quartile (HR 1.21 CI 1.18–1.32) after adjusting for potential confounders. We also found that the risk of primary brain malignancy increased in proportion with the quartile increase in height. After analyzing subgroups based on older age (≥ 65) and sex, we found positive relationships between height and primary brain malignancy in all subgroups.ConclusionsThis study is the first to suggest that height is associated with an increased risk of primary brain malignancy in the East-Asian population. Further prospective and larger studies with precise designs are needed to validate our findings.

Visit-to-visit changes in fasting blood sugar and the risk for cardiovascular disease and mortality in the Korean population: a nationwide population-based cohort study.

The importance of continuous monitoring of fasting blood sugar (FBS) levels of diabetic patients has been established. An observational prospective study was conducted. Our analysis included 1,700,796 individuals from the nationwide South Korean National Health Insurance System cohort. FBS variability was measured by standard deviation (SD). Kaplan-Meier curves demonstrated elevated disease probability in the higher FBS fluctuation group compared with the lower FBS fluctuation group. After adjusting for confounding variables, Cox proportional hazards analysis showed that the hazard ratios of 411 individuals in the highest quartile of SD variation of FBS were 1.77 (95% confidence interval 1.37-2.28, p<0.001) compared with the lowest quartile of SD variation of FBS. The impact of FBS fluctuation on the risk of cardiovascular diseases (CVDs), cerebrovascular diseases, CVD mortality and all-cause mortality in the highest quartiles of diabetic and non-diabetic individuals was statistically significant. Visit-to-visit FBS variability has prognostic value for predicting micro- and macrovascular disease, cardiovascular mortality, and all-cause mortality.

Impact of variability in estimated glomerular filtration rate on major clinical outcomes: A nationwide population-based study.

BackgroundThe estimated glomerular filtration rate (eGFR), commonly estimated using the serum creatinine value, often fluctuates throughout the serial measurement. The clinical significance of GFR variation among the general population with normal renal function has not yet been demonstrated. Thus, we explored the impact of GFR variability on adverse clinical outcomes.MethodsA nationwide retrospective cohort study using the Korean National Health Insurance System database was performed. National health screening examinees who underwent creatinine measurement ≥3 times between 2012 and 2016 were considered. Those with eGFR under 60 mL/min/m2 were excluded. The fluctuation of eGFR was represented with variability independent of the mean (VIM) index; which was calculated by the standard deviation divided by the exponent of the regression coefficient of the mean. Then, the risks of myocardial infarction (MI), stroke and death were assessed according to the quartiles of the VIMResultsOf total 3,538,500 participants, 0.29% of myocardial infarction (MI), 0.14% of stroke, 0.36% of deaths were observed during the median follow up of 3.27 years. Participants with the highest VIM index, which represents the highest eGFR variability, were significantly associated with an increased risk of MI (hazard ratio [HR]; 1.10, 95% confidence interval [95% CI]; 1.04–1.16), stroke (HR: 1.16; 95% CI 1.09–1.23), and death (HR: 1.18; 95% CI 1.12–1.24). The elevated risk of adverse events was consistent after the multivariate adjustment with potential confounding factors, except the risk of MI (HR 1.06; 95% 1.00–1.06).ConclusionsIncreased eGFR variability exhibited an association with major clinical outcomes, indicating that monitoring eGFR variability might be a useful parameter for predicting the adverse outcomes.

Differential Effect of the Metabolic Syndrome on the Incidence of Retinal Vein Occlusion in the Korean Population: A Nationwide Cohort Study.

PurposeTo investigate the impact of the metabolic syndrome (METS) on the incidence of retinal vein occlusion (RVO).MethodsThis is a retrospective cohort study using Korean National Health Insurance System data. 23,153,600 subjects without previous history of RVO underwent a National Health Screening Program examination between 2009 and 2012. They were monitored for RVO development (registration of diagnostic code for RVO) until 2015. Presence of METS was defined using the data from the National Health Screening Program examination according to the revised criteria of the National Cholesterol Education Program Adult Treatment Panel III. A multivariate adjusted Cox regression analysis was used to reveal hazard ratios and 95% confidence interval for RVO development in the presence of METS.ResultsThe age of the subjects was 47.64 ± 13.51 years. In this cohort, 11,747,439 (50.7%) were male, 11,406,161 (49.3%) were female, and 6,398,071 subjects (27.6%) were diagnosed with METS. The overall incidence of RVO was 0.947 per 1000 person-years. The adjusted hazard ratio of RVO in the presence of METS was 1.458 (95% confidence interval, 1.440–1.475; P < 0.001) after adjusting for age, sex, smoking status, alcohol consumption, physical activity, and income. Among all of the criteria for METS diagnosis, elevated blood pressure was the greatest risk for RVO development (adjusted hazard ratio, 1.610; 95% confidence interval, 1.589–1.631; P < 0.001).ConclusionsMETS and each of diagnostic criteria was associated with an increased risk of RVO development. Elevated blood pressure seems to be especially important factors for RVO development.Translational RelevanceOur results provide information about the link between METS and RVO.

Trends in End-of-Life Resource Utilization and Costs among Prostate Cancer Patients from 2006 to 2015: A Nationwide Population-Based Study.

PurposeThe purpose of this study was to evaluate end-of-life resource utilization and costs for prostate cancer patients during the last year of life in Korea.Materials and MethodsThe study used the National Health Information Database (NHIS-2017-4-031) of the Korean National Health Insurance Service. Healthcare claim data for the years 2002 through 2015 were collected from the Korean National Health Insurance System. Among 83,173 prostate cancer patients, we enrolled 18,419 after excluding 1,082 who never claimed for the last year of life.ResultsFrom 2006 to 2015, there was a 3.2-fold increase the total number of prostate cancer decedents. The average cost of care during the last year of life increased over the 10-year period, from 14,420,000 Korean won to 20,300,000 Korean won, regardless of survival time. The cost of major treatments and medications, other than analgesics, was relatively high. Radiologic tests, opioids, pain control, and rehabilitation costs were relatively low. Multiple regression analysis identified age and living in rural area as negatively associated with prostate cancer care costs, whereas income level and a higher number of comorbidities were positively associated.ConclusionsExpenditure of prostate cancer care during the last year of life varied according to patient characteristics. Average costs increased every year. However, the results suggest underutilization of support services, likely due to lack of alternative accommodation for terminal prostate cancer patients. Further examination of patterns of utilization of healthcare resources will allow policymakers to take a better approach to reducing the burden of prostate cancer care.

Suboptimal medication adherence in young women living with HIV infection: a Korean nationwide claims study

ABSTRACT The epidemiological characteristics of women living with human immunodeficiency virus (HIV) infection have gained little attention as the numbers are small compared with men living with HIV in the Republic of Korea. However, these data are important to achieve effective HIV infection control and to consider the influence of socioeconomic status on HIV transmission. This study utilized the claims database of the Korean National Health Insurance system to analyze women with a newly diagnosed HIV infection during the period 2009–2016. Adherence to antiretroviral agents was calculated using the medication possession ratio. Among 677 women with a newly diagnosed HIV infection, 219 (32.4%) were over 50 years of age; 291 (43.0%) were identified as having acquired immune deficiency syndrome (AIDS). A total of 99 women (14.6%) were National Medical Aid beneficiaries. Optimal medical adherence >95% was found in 62.2% of subjects. Teenage years (odds ratio(OR) 14.9, 95% confidence interval (95CI) 4.9-44.8), AIDS (OR 1.7, 95CI 1.2-2.3), and low economic status requiring National Medical Aid (OR 3.0, 95CI 2.0-4.6) were associated to adherence. Diagnosis prior to 2012 was also associated with poor adherence. In women, particularly young patients with low economic status, extra attention is required to enhance adherence to prescribed medication.

Effect of Variability in Blood Pressure, Glucose and Cholesterol Concentrations, and Body Weight on Emergency Hospitalization and 30-Day Mortality in the General Population.

BackgroundVariability in blood pressure, glucose concentration, cholesterol concentration, or body weight is associated with a wide range of health outcomes. We hypothesized that high variability in metabolic parameters is associated with an increased risk of emergency hospitalization and mortality.Methods and ResultsUsing a nationally representative database from the Korean National Health Insurance System, 8 049 228 individuals who underwent 3 or more health examinations during 2005 to 2010 were followed up until the end of 2016. Variability in fasting blood glucose and total cholesterol concentrations, systolic blood pressure, and body weight was measured using the variability independent of the mean (VIM). High variability was defined as the highest quartile of variability. Subjects were classified according to the number of high variability parameters. The end points of the study were emergency hospitalization and 30‐day mortality. There were 733 387 emergency hospitalizations (9.1%) during a median follow‐up of 5.6±1.2 years. For each metabolic parameter, an incrementally higher risk of emergency hospitalization was observed for higher VIM quartile groups than for the lowest quartile group. Compared with the group with low variability for all 4 parameters, the group with high variability for all 4 parameters had a significantly higher risk for emergency hospitalization (hazard ratio [HR], 1.58; 95% CI, 1.54–1.61) and 30‐day mortality (HR, 2.44; 95% CI, 1.62–3.69), after adjusting for possible confounding factors.ConclusionsHigh variability in metabolic parameters was associated with increased risk of emergency hospitalization and short‐term mortality.

Impact of smoking status and smoking cessation after coronary revascularization on long-term clinical outcomes: from a nationwide population-based study

Abstract Background There are many studies on emphasizing the importance of quitting smoking, but the smoking status was based on baseline status without subsequent status. Since a significant percentage of patients who have received coronary revascularization change their smoking status, it is necessary to confirm the clinical consequences of smoking status after revascularization. Purpose In this study, we aimed to investigate the impact of smoking status after revascularization on long-term clinical outcomes, using large population based study from the Korean National Health Insurance System. Methods Among 74,004 patients who received coronary revascularization (PCI or CABG) from 1 January 2007 to 21 December 2013 and underwent regular health check-up within 2 years after index PCI, examined for death, MI, revascularization and stroke. Results Within patients who underwent revascularization, 33,800 (45.7%) of patients were self-reported non-smoker, 28,603 (38.7%) were ex-smoker, 11601 (15.6%) were current smokers at first regular health check-up after revascularization. Current smokers were associated with higher risks for death (HR: 1.497; 95% CI: 1.366–1.641), MI (HR: 1.498; 95% CI: 1.302–1.723) and revascularization (HR: 1.088; 95% CI: 1.018–1.164) than non-smokers. Compared with non-smokers, more than 30PY ex-smokers and current smokers showed higher incidence of major adverse cardiovascular and cerebrovascular events (MACCE), defined as a composite of death, MI, revascularization and stroke. Regarding smoking tendency, maintaining non-smokers were lower risk for MACCE than maintaining smokers (Figure 1). Quitters tended to lower MACCE compared to patients who continued to smoke (HR: 0.823; 95% CI: 0.762–0.888). Especially, maintaining non-smokers and quitters significantly showed lower mortality than patients who continued to smoke. Conclusion Smoking is associated with poor clinical outcomes after coronary revascularization especially more than 30PY ex-smokers and current smokers. These results also emphasized that smoking cessation after revascularization also important for mortality benefit. Figure 1 Funding Acknowledgement Type of funding source: None

Obesity Has a Stronger Relationship with Colorectal Cancer in Postmenopausal Women than Premenopausal Women.

To examine the relationship between obesity measured by waist circumference (WC) and body mass index (BMI) and the incidence of colorectal cancer in premenopausal and postmenopausal women. A total of 1,418,180 premenopausal and 4,854,187 postmenopausal women without cancer at baseline and ages over 40 were identified using the Korean National Health Insurance System Cohort during 2009 to 2014. The hazard ratio (HR) for colorectal cancer incidence was assessed according to menopausal state using Cox proportional hazards models. During a mean follow-up period of 7.2 years, 7,094 and 57,449 colorectal cancer cases occurred in premenopausal and postmenopausal women, respectively. Compared with the reference group (WC 65-75), the HRs [95% confidence interval (CI)] of colorectal cancer in WC <65, 75-85, 85-95, and >95 groups were 1.01 (0.91-1.11), 1.02 (0.97-1.07), 1.09 (1.00-1.18), and 1.31 (1.12-1.52), respectively, in premenopausal women and 1.01 (0.95-1.17), 1.09 (1.07-1.12), 1.19 (1.00-1.18), and 1.30 (1.25-1.35), respectively, in postmenopausal women. Compared with the reference group (BMI 18.5-22.9), HRs (95% CI) for colorectal cancer in BMI <18.5, 23-25, 25-30, and >30 groups were 0.99 (0.87-1.14), 0.99 (0.94-1.06), 0.98 (0.92-1.04), and 1.06 (0.92-1.20), respectively, in premenopausal women. In postmenopausal women, those values were 0.99 (0.93-1.05), 1.05 (1.03-1.08), 1.11 (1.09-1.13), and 1.20 (1.16-1.25), respectively. WC is associated with the risk of colorectal cancer in both groups of women, but this association was stronger in postmenopausal women than in premenopausal women. BMI increased the incidence of colorectal cancer only in postmenopausal women IMPACT: Obesity has a stronger relationship with colorectal cancer in postmenopausal women than in premenopausal women.

Who Benefits from the Fixed Copayment of Medical and Pharmaceutical Expenditure among the Korean Elderly?

The Korean National Health Insurance system imposes a 30% coinsurance for outpatient medical care and prescription drugs; however, at the age of 65, the coinsurance model changes to a copayment model that offers lower fees for the elderly. Thus, this study aimed to investigate the influence of the copayment model for outpatient visits and prescription drugs on healthcare utilization among the Korean elderly. We compared total outpatient visits, total prescriptions, and out-of-pocket expenses between a case group with copayment reduction (65 years or older) and a control group without any reduction (64 years or younger). We obtained secondary data collected from seven waves of the Korea Health Panel Survey (2010–2016). Outpatient visits increased exclusively in the case group among those with lower income. After adjusting for covariates, the results of the difference-in-differences analysis showed that, compared to the control group, there was a significant increase in outpatient visits among individuals with lower income in the case group. Our study shows that cost sharing changes affect Korean patients with different income levels in different ways.

Intensive Care Unit Capacity and Its Associated Risk Factors During the COVID-19 Surge in the Republic of Korea: Analysis Using Nationwide Health Claims Data.

ObjectiveTo identify risk factors for intensive care unit (ICU) admission and mechanical ventilator usage among confirmed coronavirus disease (COVID-19) patients and estimate the effects of mitigation efforts on ICU capacity in Korea.Patients and MethodsData on profiles and medical history of all confirmed COVID-19 patients in the past 1 year were extracted from the Korean National Health Insurance System’s claims database to assess risk factors for ICU admission and ventilator use. We used a time-series epidemic model to estimate the ICU census in Daegu from the reported hospital data.FindingsMultivariate regression analysis revealed male sex, old age, and residing in Daegu city as significant risk factors for ICU admission. The number of patients requiring ICU admission exceeded the bed capacity across all Daegu hospitals before March 9, 2020, and therefore, critically ill patients were transferred to nearby hospitals outside Daegu. This finding was consistent with our prediction that the ICU census in Daegu would peak on March 16, 2020, at 160 through mitigation efforts, without which it would have reached 300 by late March 2020.ConclusionOlder age and male sex were risk factors for ICU admission. In addition, the geographic location of the hospital seems to contribute to the severity of the COVID-19 patients admitted to the ICU and to the ICU capacity.