Korean National Health Insurance Claims Research Articles

Association of physical activity with total and cause-specific mortality in patients with diabetes: A nationwide population-based cohort study

AimsPhysical inactivity is a modifiable risk factor for cardiovascular disease (CVD) in patients with type 2 diabetes mellitus (T2DM); however, little is known about its association with mortality due to other causes. Herein, we investigated the association between physical activity (PA) and cause-specific mortality in patients with T2DM. MethodsWe analyzed data from the Korean National Health Insurance Service and claims database of adults with T2DM aged >20 years at baseline (n = 2,651,214). Each participant’s PA volume was measured as the metabolic equivalent of tasks (METs)-min per week, and hazard ratios of all-cause and cause-specific mortality relative to PA levels were estimated. ResultsDuring the 7.8 years of follow-up, all-cause, CVD, respiratory, cancer, and other causes of mortality were lowest in patients engaged in vigorous PA. MET-min/week was inversely associated with mortality after adjusting for covariates. The reduction in total and cause-specific mortality was greater in patients aged ≥65 years than in those aged <65 years. ConclusionsIncreasing PA may facilitate a reduction in mortality from various causes, especially among older patients with T2DM. Clinicians should encourage such patients to increase their daily PA levels to reduce their risk of mortality.

Disparity of Bladder Cancer Incidence Among Male Workers Across Industries: A Population Based Cohort Study From South Korea.

This study aimed to investigate the bladder cancer risk across workers' industries. This study was conducted using Korean National Health Insurance claims data. Workers were included in this study to build a retrospective cohort of the entire working population. Workers' industries were divided into 77 industries according to the Korean Standard Industry Classification division category. The standardized incidence ratio was calculated by comparing 77 industries according to the Korean Standard Industry Classification with the educational public officer. Bladder cancer risk was particularly high in the following industrial sectors: passenger land transport, except transport via railways; sea and coastal water transport; restaurants and mobile food service activities; telecommunications; and computer programming, consultancy, and related activities. Our result provides evidence regarding the disparity of bladder cancer incidence among male workers across industries.

Elevated risk of cervical cancer in elderly women with incident ulcerative colitis in South Korea

The association between ulcerative colitis (UC) and uterine cervical cancer is still unclear. To investigate cervical cancer risk in South Korean women with UC, we analyzed the Korean National Health Insurance claims data. UC was defined using both ICD-10 codes and UC-specific prescriptions. We analyzed incident cases of UC diagnosed between 2006 and 2015. Age-matched women without UC (control group) were randomly selected from the general population (1:3 ratio). Hazard ratios were calculated using multivariate Cox proportional hazard regression, and the event was defined as occurrence of cervical cancer. A total of 12,632 women with UC and 36,797 women without UC were enrolled. The incidence of cervical cancer was 38.8 per 100,000 women per year in UC patients and 25.7 per 100,000 women per year in controls, respectively. The adjusted HR for cervical cancer was 1.56 (95% CI 0.97–2.50) in the UC group with reference to the control group. When stratified by age, the adjusted HR for cervical cancer was 3.65 (95% CI 1.54–8.66) in elderly UC patients (≥ 60 years) compared to elderly control group (≥ 60 years). Within UC patients, increased age (≥ 40 years) and low socioeconomic status were associated with an increased risk of cervical cancer. The incidence of cervical cancer was found to be higher among elderly patients (≥ 60 years) with newly diagnosed UC in South Korea, compared to age-matched controls. Therefore, regular cervical cancer screening is recommended for elderly patients who have recently been diagnosed with UC.

Risk of adverse obstetric outcomes in patients with a history of endometrial cancer: A nationwide population-based cohort study.

To evaluate adverse obstetric outcomes in women with a history of endometrial cancer (EC). Population-based cohort study. The Korean National Health Insurance (KNHI) claims database. Women who gave birth between 2009 and 2016, with a history of EC prior to pregnancy. The KNHI database was used to compare obstetric outcomes of women with and without a history of EC, using the ICD-10 codes. Multivariable logistic regression models were used to determine the associations between a history of EC and adverse obstetric outcomes. Adverse obstetric outcomes. Overall, 248 and 3 335 359 women with and without a history of EC, respectively, gave birth. When adjusted for age, primiparity and comorbidities, an increased risk of multiple gestations (odds ratio [OR] 4.925, 95% confidence interval [CI] 3.394-7.147), caesarean delivery (OR 2.005, 95% CI 1.535-2.62) and preterm birth (OR 1.941, 95% CI 1.107-3.404) was observed among women with a history of EC. We were unable to demonstrate significant differences in the risk of pre-eclampsia, gestational diabetes, vacuum delivery, placenta praevia, placenta accreta spectrum, placental abruption and postpartum haemorrhage between the groups. In the sensitivity analyses excluding multiple gestations, an increased risk of preterm birth was not observed among women with a history of EC (OR 1.276, 95% CI 0.565-2.881). There is no convincing evidence of an increased risk of adverse obstetric outcomes among women with a history of EC. Our findings would be useful in counselling of patients with EC who are undergoing fertility-sparing treatment.

Comparison of pneumonia incidence between long-acting muscarinic antagonist and inhaled corticosteroid plus long-acting beta agonist in patients with COPD

Few studies have directly compared the incidence of pneumonia in patients on common chronic obstructive pulmonary disease (COPD) treatments such as long-acting muscarinic antagonists (LAMA) with those on inhaled corticosteroids and long-acting β2-agonist (ICS/LABA). Moreover, risk factors for pneumonia in COPD are still unclear. We aimed to compare the incidence of pneumonia in COPD patients on LAMA and those on ICS/LABA and explored the risk factors associated with pneumonia. This nationwide cohort study used Korean National Health Insurance claim data from January 2002 to April 2016. Patients who received COPD medication, either LAMA or ICS/LABA, with the COPD diagnostic code, were selected. We enrolled patients with good compliance (medication possession ratio ≥ 80%). The primary outcome was pneumonia in COPD patients initiating LAMA or ICS/LABA. We investigated the risk factors associated with pneumonia, including the sub-types of ICS treatments. After propensity score matching, the incidence rate per 1000 person-years of pneumonia was 93.96 for LAMA (n = 1003) and 136.42 for ICS/LABA (n = 1003) patients (p < 0.001). The adjusted hazard ratio (HR) for pneumonia in patients on fluticasone/LABA was 1.496 (95% confidence interval [CI] 1.204–1.859) compared with LAMA (p < 0.001). In multivariable analysis, a history of pneumonia was a risk factor associated with pneumonia (HR 2.123; 95% CI 1.580–2.852; p < 0.001). The incidence of pneumonia was higher in COPD patients on ICS/LABA compared with those on LAMA. It is recommended that ICS use be avoided in COPD patients with high pneumonia risk.

Longitudinal trends in direct costs and healthcare utilization ascribable to inflammatory bowel disease in the biologic era: a nationwide, population-based study.

Biologic-era data regarding the direct cost and healthcare utilization of inflammatory bowel disease at the population level are limited, especially in Asia. Thus, we aimed to investigate the nationwide prevalence, direct cost, and healthcare utilization of inflammatory bowel disease in Korea in a recent 10-year period. Using the Korean National Health Insurance claim data from 2008 to 2017, we investigated all prescription medications and their associated direct costs, hospitalizations, and outpatient visits. We also estimated the nationwide prevalence of inflammatory bowel disease using population census data. The estimated inflammatory bowel disease prevalence significantly increased from 108.8/100 000 in 2008 to 140.4/100 000 in 2017. The overall annual costs for inflammatory bowel disease and the healthcare cost per capita increased from $24.5 million (in US dollars) to $105.1 million and from $458.4 to $1456.6 million, respectively (both P<0.001). Whereas the ratio of outpatient costs increased from 35.3% to 69.4%, that of outpatient days remained steady. The total annual medication cost and proportion rose from $13.3 million to $76.8 million and from 54.2% to 73.3%, respectively, mainly due to the increasing antitumor necrosis factor cost, from $1.5 million to $49.3 million (from 11.1% to 64.1% of the total annual drug cost and from 6.3% to 46.9% of the total annual cost). We observed increasing trends in the prevalence, direct costs, and healthcare utilization of inflammatory bowel disease in Korea in recent years. The attributable cost was mainly driven by rising expenditures on antitumor necrosis factor medications.

Association of polypharmacy with all-cause mortality and adverse events among elderly colorectal cancer survivors.

The risk of inappropriate drug exposure in elderly colorectal cancer (CRC) survivors after the initial cancer treatment has not been well studied. This study investigated the association of polypharmacy (PP) with overall survival, hospitalization, and emergency room (ER) visits among older CRC survivors. A retrospective cohort study was conducted using the Korean National Health Insurance claims data follow-up from 2002 to 2017. Participants comprised those aged ≥65years who were hospitalized with a diagnosis of CRC received cancer treatment and survived at least 2years from the initial CRC diagnosis between 2003 and 2012. PP was defined based on the number of individual drugs during the third year, after 2years of survival since the initial cancer treatment. PP was categorized as follows: non-PP (zero to four prescribed drugs); PP (five to nine drugs), and excessive PP (≥10 drugs). Main outcomes are all-cause mortality, hospitalization, and ER visits. Of the 55,228 participants, 44.5% died, 83.1% were hospitalized, and 46.1% visited the ER. The PP and excess PP groups showed increased risk of all-cause mortality, hospitalization, and ER visit compared with the low PP group, and was highly associated among groups including patients aged 65 to 74years and those in low-level frailty groups. These risks can be minimized by increasing awareness and enhancing behaviors among health care professionals, especially clinician and pharmacists, to be aware of potential drug interactions, review, and ongoing monitoring. The risk of inappropriate drug exposure in older colorectal cancer (CRC) survivors after the initial cancer treatment has not been well studied. Polypharmacy was associated with adverse outcomes, including all-cause mortality, hospitalization, and emergency room visits among older CRC survivors and it was particularly associated with those who were 65 to 75years and those with low risk of frailty. When prescribing drugs, physicians should be mindful of finding a balance between adequate treatment of diseases and avoiding adverse drug effects in survivors of CRC.

Gender disparities in prevalence by diagnostic criteria, treatment and mortality of newly diagnosed acute myocardial infarction in Korean adults

Acute myocardial infarction (AMI) is highly prevalent and remains the leading cause of mortality. Particularly in women, under-recognition and management of AMI have been raised. The aim of this study was to investigate the long-term trends of prevalence, treatment methodologies, and mortality of AMI by gender. The subjects of this study were patients hospitalized for AMI according to the Korean National Health Insurance Claims Database from 2002 to 2018. Total 633,097 AMI patients were hospitalized, 40% women. The incidence of AMI has been increasing since 2011, with a lower incidence in women. Overall, 53.1% of patients underwent CAG, with a lower tendency in women than in men (39.8% vs. 62.3%). Furthermore, fewer women underwent PCI than men (77.5% vs. 85.8% in 2018, p < 0.0001). Of the 336,463 AMI patients undergoing CAG, women were undertreated with a lower prescription rate of beta-blockers or statins at discharge. When adjusted for age, women showed higher 7-day mortality but lower 1-year mortality relative to men. According to the Korean National Health Insurance Claims Database, women with AMI have been under-recognized, underdiagnosed, and undertreated in terms of revascularization or medical therapy for years suggesting that efforts to close the gender gap are necessary.

Who are the most vulnerable populations for primary care? Avoidable hospitalizations across individuals with different types of disabilities in South Korea

BackgroundIndividuals with disabilities have limited access to primary care, the quality of care must be examined. ObjectiveTo examine avoidable hospitalizations among individuals with disabilities and determine the most vulnerable populations across types of disabilities. MethodsUsing the Korean National Health Insurance Claims Database, we compared hypertension- and diabetes-related avoidable hospitalizations (HRAH and DRAH, respectively) across disability status and disability type based on age-sex standardized rates from 2011 to 2020 and logistic regression. ResultsThe gap between those with and without disabilities in age-sex standardized HRAH and DRAH increased over 10 years. Odds ratios for HRAH were higher for those with disabilities, with individuals with mental disabilities having the highest odds ratio, followed by those with intellectual/developmental disabilities, then those with physical disabilities; for DRAH, the three highest odds ratios belonged to individuals with mental, intellectual/developmental, and visual disabilities. Among those with disabilities, HRAH was higher for those with mental, intellectual/developmental, and severe physical disabilities, whereas DRAH was higher for those with mental, severe visual, and intellectual/developmental disabilities compared to those with mild physical disabilities. ConclusionThis study reveals high avoidable hospitalization rates among individuals with disabilities and calls for policies supporting quality primary care and comprehensively addressing disparities.

P659 Continuing or stopping 5-aminosalicylate in patients with Inflammatory Bowel Disease under anti-TNF therapy: A nationwide population-based study

Abstract Background The clinical impact of continuing or stopping 5-aminosalicylate (5-ASA) after escalating to treatment with an anti-tumour necrosis factor (TNF) agent in patients with inflammatory bowel disease (IBD) is currently unclear. We aimed to compare the outcomes of IBD patients who stopped or continued 5-ASA after starting anti-TNF therapy. Methods We analysed data obtained from the Korean National Health Insurance claims database between 2007 and 2020. Our analysis included IBD patients already on 5-ASA treatment who started anti-TNF treatment. We compared the prognosis of patients who stopped 5-ASA within 90 days of anti-TNF initiation with those who continued 5-ASA. The primary outcome was any adverse clinical event defined as a composite of intestinal surgery, IBD-related hospitalization, or new corticosteroid use. Kaplan-Meier method and Cox proportional hazards models at landmark time were used to calculate adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs). Results Among 62,262 patients diagnosed with IBD during the study period, 7,442 patients were included for analysis. A total of 1,037 (13.9%) patients discontinued 5-ASA within 90 days of starting anti-TNF therapy (Figure 1). Among the included patients, 4,479 (60.2%) had Crohn’s disease, while 2,963 (39.8%) had ulcerative colitis (Table 1). Discontinuation of 5-ASA was not associated with an increased risk of any adverse clinical events, as well as its component outcomes of intestinal surgery, IBD-related hospitalization, and corticosteroid use, with aHRs of 1.011 (95% CI, 0.934 to 1.095), 0.954 (95% CI 0.760 to 1.198), 0.995 (95% CI 0.894 to 1.107), and 0.969 (95% CI, 0.890 to 1.056), respectively (Table 2). In addition, the cumulative incidence of each adverse clinical event, as well as the composite outcome, were not significantly different between the two groups (all, p &amp;gt; 0.05) (Figure 2). Subgroup analysis by sex, IBD type, the timeframe of anti-TNF use, pre-anti-TNF 5-ASA use duration, pre-anti-TNF corticosteroid use, pre-anti-TNF hospitalizations, pre-anti-TNF emergency department visits, and anti-TNF agent type also showed no significant difference in the development of adverse clinical events between the two groups. Conclusion In this nationwide population-based study, we observed that discontinuing 5-ASA after starting anti-TNF therapy was not associated with an increased risk of adverse clinical events.

P833 Cervical cancer risk in newly diagnosed ulcerative colitis: a nationwide population-based study

Abstract Background The association between ulcerative colitis (UC) and increased risk of cervical cancer in women remains controversial. We investigated cervical cancer risk in South Korean UC patients using the Korean National Health Insurance (NHI) claims data. Methods UC definitions included both ICD-10 codes and UC-specific prescriptions. We analyzed incident cases diagnosed between 2006 and 2015. Age-matched women without UC (control group) were randomly selected from the general population (1:3 ratio). Hazard ratios (HRs), adjusted for different covariates, were calculated using multivariate Cox proportional hazard regression. In total, 12,632 and 36,797 women with and without UC, respectively, were enrolled. Results Cervical cancer developed in 0.21% (68 person-years) and 0.14% (172 person-years) of UC patients and controls, respectively. The HR (95% CI) of cervical cancer in the UC group, with reference to the control group, was 1.56 (0.97-2.50). HR, stratified by age, was significantly high in elderly UC patients (≥60 years) at 3.65 (1.54–8.66). In UC patients, old age (≥40 years) and low socioeconomic status were associated with increased cervical cancer risk. Conclusion Elderly UC patients had a higher incidence of cervical cancer than age-matched controls in Korea, suggesting that elderly patients with newly diagnosed UC should be screened for cervical cancer.

A Decline in Overutilization of Transfusion after Total Knee Arthroplasty Using Pharmacological Agents for Patient Blood Management in South Korea: An Analysis Based on the Korean National Health Insurance Claims Database from 2008 to 2019.

This study aimed to evaluate the annual trends of transfusion rates and utilization of blood management agents in total knee arthroplasty (TKA) based on the operation type and to analyze the risk factors of transfusion after TKA. Using the Korean National Insurance claims database of 797,106 primary and revision TKAs between January 2008 and October 2019, data on the patients' characteristics, comorbidities, utilization of transfusion, and blood management agents were collected. The patients were categorized into three groups based on the operation type: primary, revision, and simultaneous bilateral TKA. The transfusion rate and utilization of blood management agents (intraoperative tranexamic acid [TXA] and preoperative iron supplements) were compared, and the risk factors for transfusion were evaluated. After excluding the inaccurate data, 730,554 arthroplasties (636,292 primary, 10,540 revision, and 41,861 simultaneous bilateral TKAs) were identified. The transfusion rates of primary, revision, and simultaneous bilateral TKAs in 2019 were 64.0%, 67.7%, and 68.9%, respectively, which were significantly decreased compared with 83.2%, 88.0%, and 92.5% in 2008, respectively (p < 0.001). Conversely, the utilization of intraoperative TXA and preoperative iron supplements was significantly increased from 4.6% and 13.8%, respectively, in 2008 to 52.4% and 27.0%, respectively, in 2019 (p < 0.001). The utilization of intraoperative TXA and preoperative iron supplements significantly lowered the risk of transfusion after TKA (odds ratio [OR], 0.20; p < 0.001 and OR, 0.71; p < 0.001). The transfusion rate after TKA decreased gradually from 83.5% to 64.5% between 2008 and 2019 in South Korea corresponding with the increased utilization of blood management agents. Therefore, consistent attention to patient blood management should be emphasized to reduce the transfusion rate after TKA.

Maternal Polycystic Ovary Syndrome and the Risk of Early Childhood Obesity in Female Offspring: A Nationwide Population-Based Study.

To investigate the relationship between polycystic ovary syndrome (PCOS) in Korean women and childhood growth and obesity of their offspring. This longitudinal case-control study using the Korean National Health Insurance claims database and the National Health Screening Program for Infants and Children database included women who delivered singletons between January 2007 and December 2008. Offspring's body mass index (BMI) measurements taken between 42 and 80 months of age were compared according to a maternal history of PCOS. Among a total of 131,805 participants, 1,213 women had a history of PCOS and 130,592 women did not. Female offspring aged 66-80 months born to women with PCOS had significantly higher BMI than those born to women without PCOS; there was no significant difference in that of male offspring regardless of maternal PCOS. In the generalized estimating equation and multivariable logistic regression analyses, the female offspring born to women with PCOS had a significantly higher risk of obesity during the age of 42-54 and 66-80 months (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.09-2.21 and OR, 1.5; 95% CI, 1.05-2.15, respectively), than those born to women without PCOS, after adjusting for several confounding factors. Maternal PCOS is independently associated with an increased incidence of childhood obesity in female offspring among Korean women. Women with PCOS should consider the risk of early childhood obesity in their daughters, even if they maintain a healthy weight themselves.

Trends in National Pharmaceutical Expenditure in Korea during 2011 - 2020.

This study aimed to identify the trends in pharmaceutical expenditure (PE), share of PE in health expenditure (HE), and trends in expenditure by pharmacological groups (ATC level 1 classification) in Korea for a 10-year period (2011 - 2020) and compare the data with those of other Organisation for Economic Co-operation and Development (OECD) countries. Using the findings, we determined the current status of pharmaceutical expenditure (PE) management in Korea and derived the implications for establishing future macroscopic policies on PE. We analyzed the OECD Health Statistics and the Korean national health insurance claims database from January 2011 through December 2020. The outcome measures were HE, PE, and pharmaceutical sales data for ATC level 1 medicines from OECD Health Statistics data during 2011 - 2020. As OECD collects limited ATC level 1 data, we used the HIRA health insurance claims data for PEs of ATC level-1 classification, including D, L, P, and S. PE in Korea increased by 38.5% from 19.9 billion USD in 2011 to 27.6 billion USD in 2020, whereas the share of PE in HE decreased by 6.3%p from 26.4% in 2011 to 20.1% in 2020. In 2020, Korea ranked third in PE per capita (760.9 USD PPP) and had the highest share of PE (20.1%) among the 19 OECD countries studied. By ATC level 1 class, the highest PE was A (alimentary tract and metabolism) at 4.3 billion USD, and L (antineoplastic and immunomodulating agents) had the highest increase at 13.4%; in contrast, J (anti-infectives for systemic use) had the lowest increase in annual average PE at -0.2% in 2020 relative to 2011. Among the 17 OECD countries, Korea had the highest and the third-highest expenditures for ATC codes A and J, respectively. PE in Korea has continued to increase between 2011 and 2020, indicating the need for macroscopic management of PE. Our results on PE by ATC code may help health authorities in establishing future policies on PE.

Major Congenital Anomalies in Korean Livebirths in 2013-2014: Based on the National Health Insurance Database.

In Korea, there have been no reports comparing the prevalence of major congenital anomalies with other countries and no reports on surgical treatment and long-term mortality. We investigated the prevalence of 67 major congenital anomalies in Korea and compared the prevalence with that of the European network of population-based registries for the epidemiological surveillance of congenital anomalies (EUROCAT). We also investigated the mortality and age at death, the proportion of preterm births, and the surgical rate for the 67 major congenital anomalies. Korean National Health Insurance claim data were obtained for neonates born in 2013-2014 and admitted within one-year-old. Sixty-seven major congenital anomalies were defined by medical diagnoses classified by International Classification of Diseases-10 codes according to the EUROCAT definition version 2014. Mortality and surgery were defined if any death or surgery claim code was confirmed until 2020. Poisson distribution was used to calculate the 95% confidence interval of the congenital anomaly prevalence. The total prevalence of the 67 major anomalies was 433.5/10,000 livebirths. When compared with the prevalence of each major anomaly in EUROCAT, the prevalence of spina bifida, atrial septal defect (ASD), congenital megacolon, hip dislocation and/or dysplasia and skeletal dysplasia were more than five times higher in Korea. In contrast, the prevalence of aortic atresia/interrupted aortic arch and gastroschisis was less than one-fifth in Korea. The proportion of preterm births was 15.7%; however, more than 40% of infants with anencephaly, annular pancreas and gastroschisis were preterm infants. Additionally, 29.2% of the major anomalies were admitted to the neonatal intensive care units at birth, and 25.6% received surgical operation. The mortality rate was 1.7%, and 78.2% of the deaths occurred within the first year of life. However, in neonates with tricuspid valve atresia and stenosis, duodenal atresia or stenosis, and diaphragmatic hernia, more than half died within their first month of life. ASD and ventricular septal defect were the most common anomalies, and trisomy 18 and hypoplastic left heart syndrome were the most fatal anomalies. All infants with aortic atresia/interrupted aortic arch and conjoined twins received surgery. The proportion of surgeries, preterm births and mortality was high in infants with major congenital anomalies. The establishment of a national registry of congenital anomalies and systematic support by national medical policies are needed for infants with major congenital anomalies in Korea.

Collateral Effect of the Coronavirus Disease 2019 Pandemic on Emergency Department Visits in Korea.

Background and Objectives: The ongoing coronavirus disease 2019 (COVID-19) pandemic represents a global public health crisis that has had a serious impact on emergency department (ED) utilization trends. The aim of this study was to investigate the collateral effects of the COVID-19 pandemic on ED utilization trends by patients with mild and severe conditions as well as on 7-day fatality rates. Materials and Methods: We analyzed entries in the Korean National Health Insurance claims database between 1 January 2018 and 31 December 2020. Six target patient groups were identified using the main diagnosis codes in the 10th revision of the International Classification of Diseases. Numbers of patients visiting the ED, their age, regional differences, 7-day fatality rate, and rate of emergency procedures were compared between 2018 and 2019 as the control period and 2020, when the COVID-19 pandemic was in full force. Results: During the 2020 COVID-19 pandemic, the number of patients who visited the ED with low-acuity diseases and severe acute respiratory infection diseases sharply decreased to -46.22% and -56.05%, respectively. However, the 7-day fatality rate after ED visits for low-acuity diseases and severe acute respiratory infection diseases increased to 0.04% (p &lt; 0.01), and 1.65% (p &lt; 0.01), respectively, in 2020 compared to that in the control period. Conclusions: During the 2020 COVID-19 pandemic, ED utilization impacted and 7-day fatality rate after ED visit increased. Health authorities and health care providers must strive to ensure prompt delivery of optimal care in EDs for patients with severe or serious symptoms and time-dependent diseases, even during the ongoing COVID-19 or potential future pandemics.

Metformin and Cervical Cancer Risk in Patients with Newly Diagnosed Type 2 Diabetes: A Population-Based Study in Korea.

Cervical cancer is a prevalent malignancy that is a major health problem for women worldwide. The cancer-preventive properties of metformin are well-known, but insufficient data have been reported regarding its relationship to cervical cancer. Therefore, in a nationwide population-based study, we investigated the association between metformin use and cervical cancer incidence in patients with newly diagnosed type 2 diabetes. This retrospective cohort study used the Korean National Health Insurance claims database. Individuals newly diagnosed with type 2 diabetes between January 2005 and December 2009 were included. The occurrence of cervical cancer was explored by matching for age, economic status, region of residence, and use of anti-diabetic medication. In total, 66,013 metformin users and 64,756 non-users were analyzed. Cervical cancer occurred in 219 metformin users (0.33%) and 274 metformin non-users (0.42%) (hazard ratio [HR], 0.783; 95% confidence interval [CI], 0.655 to 0.036; P=0.007). Moreover, cervical cancer risk was considerably reduced in those treated with a high dose (>1,200,000 mg) or for an extended period (≥2,000 days) compared to non-users (HR, 0.151; 95% CI, 0.093 to 0.243; P<0.001; and HR, 0.141; 95% CI, 0.077 to 0.258; P<0.001). The incidence was also significantly lower in metformin users among those over 50 years old (HR, 0.791; 95% CI, 0.650 to 0.961; P<0.001). Metformin use in patients with newly diagnosed diabetes was associated with a lower risk of cervical cancer in Korea. Furthermore, a significant association was found between the use of metformin and cervical cancer in a dose- and duration-dependent manner and among those over 50 years old.

Pregnancy outcomes after living kidney donation from a nationwide population-based cohort study from Korea

While most living kidney donors experience good outcomes and high rates of satisfaction, kidney donation can increase the risk of gestational hypertension or preeclampsia. However, pregnancy outcomes in non-white donors are limited. We conducted a nationwide cohort study of 112 living kidney donors and 672 matched healthy non-donors using the Korean National Health Insurance Claims Database. Donors and healthy non-donors were matched according to age, year of cohort entry, residency, income, number of pregnancies, and the time to the first pregnancy after cohort entry. We assessed pregnancy outcomes of live kidney donors compared with matched healthy non-donors using the nationwide database. Gestational hypertension or preeclampsia was more common in kidney donors than in non-donors (8.9% vs. 1.8%; adjusted odds ratio, 2.68; 95% confidence interval, 1.11–6.50). However, the incidence of severe gestational hypertension or preeclampsia that required antihypertensive medication was comparable (2.7% vs. 0.9%; P = 0.121). The time from donation to delivery within 5 years and primiparity were risk factors for preeclampsia in donors. Low birth weight, stillbirth, and ectopic pregnancy were not significantly different between the two groups. Maternal death occurred in two non-donor cases, but none occurred in donors compared to non-donors. Our findings indicate that kidney donors are associated with an increased risk of gestational hypertension or preeclampsia than matched healthy non-donors. However, the probabilities of serious maternal and fetal outcomes remained low and are not increased significantly after kidney donation.

Clinical characteristics of patients with recurrent Kawasaki disease: a nationwide cohort study of 19 456 patients with minimum 3-year follow up

ObjectiveTo identify the clinical characteristics of patients with recurrent Kawasaki disease (KD).DesignA nationwide, population-based, cohort study using the Korean National Health Insurance claims database between 2013 and 2016.PatientsA total of...

Comparison of Previous Infectious and Allergic Diseases Between Patients with Kawasaki Disease and Propensity Score–matched Controls: A Nationwide Cohort Study

To determine whether previous infectious and allergic diseases are associated with the development of Kawasaki disease in children. This nationwide, population-based, case-control study used data from the Korean National Health Insurance claims database. The entire cohort consisted of patients younger than 5years of age diagnosed with Kawasaki disease and 1:5 propensity score-matched controls from 2013 to 2019. The epidemiologic features and previous infectious or allergic diseases between the 2 groups were compared, and potential factors that could influence the association were identified. In total, 32 964 patients diagnosed with Kawasaki disease and 164 820 controls were included. Patients with Kawasaki disease had more frequent diagnoses of previous sepsis or bacteremia (OR 1.41), acute pyelonephritis (OR 1.10), and otitis media (OR 1.24). In addition, Kawasaki disease was associated with previous diagnoses of atopic dermatitis (OR 1.05), urticaria (OR 1.08), and asthma (OR 1.05). The association between previous infectious or allergic diagnoses and Kawasaki disease was more prominent in younger patients (<2years). However, intravenous immunoglobulin resistance, sex, and region of residence were not significant factors that consistently influenced the association between previous infectious or allergic diseases and Kawasaki disease. Despite the increased rates of previous infectious and allergic diseases in patients with Kawasaki disease compared with controls, the association between allergic diseases and Kawasaki disease was weaker in our cohort than in previous studies.