Korea National Health Insurance Research Articles

Common Cancer-Related Factors and the Risk of Developing Kaposi Sarcoma in Individuals without AIDS: Korea National Health Insurance Services Claims Database.

Backgrounds: Kaposi sarcoma (KS) is a unique form of cancer with epidemiological characteristics distinct from those of other solid cancers. While common risk factors including alcohol consumption, smoking, and metabolic disorders have been well studied in various cancers, their relationship with KS remains unclear. Methods: This study used a cohort approach with adults without AIDS, utilizing data from the National Health Insurance Service in South Korea. This study examined various conventional cancer-related risk factors related to the incidence of KS, including psoriasis. Results: Alcohol consumption, smoking, body mass index, diabetes mellitus, hypertension, hypercholesterolemia, and regular exercise were not significantly associated with the incidence of KS. Additionally, older age and male sex were associated with a higher incidence of KS. KS risk was increased in pathological conditions such as psoriasis and proteinuria, which require immunosuppressive medication. Conclusions: Our study suggests that traditional cancer-related risk factors may not play a significant role in the pathogenesis of KS, unlike other cancers. This, in turn, emphasizes the importance of immunosuppression and HHV-8 infection in the development of KS.

Cancer risk among air transportation industry workers in Korea: a national health registry-based study

BackgroundFlight attendants face various risk factors in their working environments, particularly occupational exposure to cosmic radiation. This study aimed to assess cancer risk among air transportation industry workers, including flight attendants, in Korea by constructing a cohort using national health registry-based data and analyzing cancer incidence risk.MethodsWe used the Korea National Health Insurance Service database from 2002 to 2021 to construct a cohort of 37,011 workers in the air transportation industry. Cancer incidence was defined using the tenth version of the International Classification of Diseases. We calculated the age- and sex-specific standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) by applying the cancer incidence rate of the general population between 2002 and 2019.ResultsApproximately 5% of the cohort developed cancer. Overall, the cancer incidence in the cohort was similar to or lower than that of the general population, with the SIRs for all cancers being lower. However, significantly higher SIRs were observed for nasopharyngeal cancer (SIR, 3.21; 95% CI, 1.71–5.48) and non-Hodgkin lymphoma (SIR, 1.57; 95% CI, 1.02–2.32) in male workers and breast and genital cancer (SIR, 1.51; 95% CI, 1.34–1.70) and thyroid cancer (SIR, 1.25; 95% CI, 1.05–1.47) in female workers.ConclusionsThe lower overall cancer incidence among air transportation industry workers observed in this study could indicate the “healthy worker effect”; however, the incidences of certain cancers were higher than those in the general population. Given that these workers are exposed to multiple occupational and lifestyle-related risk factors, including cosmic radiation, further studies are necessary to determine radiation-induced cancer risk while considering potential confounding factors.

COVID-19 Vaccination and Ocular Adverse Events: A Self-Controlled Case Series Study From the Entire South Korean Population

This study aimed to assess the risk of ocular adverse events, including retinal artery occlusion (RAO), retinal vein occlusion (RVO), noninfectious uveitis (NIU), noninfectious scleritis (NIS), optic neuritis (ON), ischemic optic neuropathy (ION), and ocular motor cranial nerve palsy (OMCNP), following Coronavirus Disease 2019 (COVID-19) vaccination. Population-based self-controlled case series METHODS: This study utilized nationwide claims and vaccination data provided by the Korea National Health Insurance Service and Korea Disease Control and Prevention Agency. From the entire South Korean population of 52 million individuals, patients with incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP between January 2021 and March 2022 were included. The postvaccination risk period was defined as up to 56 days after COVID-19 vaccination. The relative incidence rate ratios (IRRs) for RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP during the risk periods were measured using conditional Poisson regression. The study included 6,590, 70,120, 137,958, 17,921, 15,492, 2,039, 49,089, and 11,312 cases of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP, respectively. The IRRs (95% confidence interval) during the early risk period (0-28 days) were 0.95 (0.88-1.01), 0.96 (0.94-0.98), 0.93 (0.91-0.94), 0.93 (0.89-0.96), 0.96 (0.92-1.01), 1.04 (0.92-1.18), 0.98 (0.95-1.00), and 0.91 (0.86-0.96), respectively. In the late risk period (29-56 days), the IRRs were 0.96 (0.89-1.03), 0.93 (0.91-0.96), 0.96 (0.95-0.98), 1.00 (0.95-1.04), 0.96 (0.91-1.01), 1.00 (0.87-1.15), 1.01 (0.98-1.04), and 0.95 (0.90-1.01), respectively. COVID-19 vaccination did not increase the risk of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP during the postvaccination period.

Impact of early economic activity loss on all-cause mortality in gastric cancer survivors following curative treatment: a nationwide study in Korea.

The impact of economic engagement on the health of cancer survivors is notable. Our study aims to explore the association between early loss of economic activity (EA) and the risk of all-cause mortality among gastric cancer survivors. This retrospective cohort study utilized data from Korea's National Health Insurance Service, focusing on 30-59-year-old gastric cancer patients who received either surgery or endoscopic procedures from January 2009 to December 2013. The primary outcome measure was all-cause mortality. Early loss of EA was identified when a patient's insurance status shifted to dependent within one year following treatment. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality were estimated using multivariable Cox proportional hazards models, conducting separate analyses for surgical and endoscopic groups. Among 24,159 patients (median follow-up, 9.9years), 2976 (12.3%) experienced all-cause mortality. Specifically, 2835 of these deaths occurred in patients who underwent surgery, while 141 were in the endoscopic procedure group. Early loss of EA was recorded in 14.4% of the surgery group and 7.7% of the endoscopic procedure group. Adjusted HRs (95% CI) for all-cause mortality associated with early loss of EA were 1.39 (1.27-1.54) for the surgery group and 2.27 (1.46-3.52) for the endoscopic procedure group. This study highlights a significant association between the early loss of EA and an increased risk of all-cause mortality in those who have undergone curative treatments for gastric cancer. It underscores the crucial role of sustaining EA in enhancing the health outcomes of these survivors.

Dementia Incidence in Survivors of Multiple Myeloma: A National Case-Control Study Conducted in Korea (The CAREMM-2106 Study)

BackgroundDementia, a growing global health issue, affects older adults and specific groups like long-term cancer survivors. The link between cancer survival and dementia is debated. Multiple myeloma (MM), a common blood cancer in older adults, is often linked with cognitive issues. This study investigated dementia incidence in long-term MM survivors using Korean national data. MethodsA retrospective case-control study used data from the Korea National Health Insurance Service (KNHIS), covering about 50 million Koreans. Patients diagnosed with MM between 2009 and 2020 formed the case cohort, while the control cohort included matched individuals without MM using propensity-score matching. Analyzing baseline characteristics, comorbidities, and socioeconomic status, the primary outcome was dementia incidence identified via ICD-10 codes. Statistical methods included Kaplan-Meier plots, cause-specific and Fine–Gray subdistribution hazard models, and a 3-year landmark analysis for immortal time bias. ResultsThe study included 33,864 patients, with 16,932 in each cohort. The overall cumulative dementia incidence was lower in the MM cohort compared to controls. However, in the first 3 years, MM patients had a higher dementia risk (HR: 1.711, 95% CI, 1.562-1.874) than controls. After 3 years, the risk significantly decreased (HR: 0.625, 95% CI, 0.560-0.696). Age-specific analysis showed a consistent pattern, particularly among MM patients aged 70-79, where dementia risk increased post-3 years. ConclusionThis study reveals a lower long-term dementia risk in MM survivors compared to non-MM individuals. Further prospective studies are needed to confirm these findings and explore the underlying mechanisms.

Dementia incidence varied by anticancer drugs and molecular targeted therapy in a population-based cohort study

Anticancer drugs may affect the incidence of dementia by modulating the common pathophysiology between cancer and dementia. However, there is a paucity of research that focused on anticancer drugs with different mechanisms of action and their associations with subtypes of dementia. Therefore, we aimed to investigate the incidence of dementia according to various groups of anticancer drugs. From the Korea National Health Insurance Service database, our retrospective population-based cohort study enrolled 116,506 cancer patients aged 65 years and older who received anticancer drugs between January 1, 2008 and December 31, 2018. The hazard ratio was determined using Cox proportional hazards regression models, comparing each group of anticancer drugs to all other anticancer drugs, after adjusting for covariates. Antimetabolites (HR = 0.91; 95% CI 0.84–0.97) and molecular targeted therapies (HR = 0.60; 95% CI 0.49–0.74) were associated with a decreased incidence of dementia of the Alzheimer type (DAT), but not with vascular dementia. Among molecular targeted therapies, epidermal growth factor receptor inhibitors (HR = 0.60; 95% CI 0.46–0.79) and multikinase inhibitors (HR = 0.49; 95% CI 0.27–0.89) were associated with a low incidence of DAT only. Our findings highlight the potential for targeted repurposing of anticancer drugs to prevent dementia.

Association of remnant cholesterol with risk of dementia: a nationwide population-based cohort study in South Korea

The association between remnant cholesterol (remnant-C) and cardiovascular disease risk is well established, but its association with dementia remains unclear. We aimed to examine this association using a large-scale population dataset. We did a nationwide, population-based cohort study in which we identified participants aged 40 years and older who underwent the national health examination in 2009 from South Korea's National Health Insurance Service. We excluded people who were younger than 40 years and those with a triglyceride concentration of 400 mg/dL or higher due to concerns regarding the accuracy of calculated low-density lipoprotein cholesterol concentration in individuals with extremely high triglyceride concentrations. People who were previously diagnosed with dementia before the index date, and those who had any missing variables were also excluded. To minimise the influence of possible reverse causation, we excluded individuals who had developed any type of dementia within 1 year of the baseline measurements. We calculated hazard ratios (HRs) for all-cause dementia, Alzheimer's disease, and vascular dementia in each quartile of remnant-C using the Cox proportional hazards model adjusted for age, sex, body-mass index, estimated glomerular filtration rate, income level, smoking status, alcohol consumption, regular exercise, diabetes, hypertension, statin and fibrate use, and total cholesterol concentrations. We also did subgroup analyses to investigate the association between remnant-C and the risk of dementia stratified by age, sex, obesity, glycaemic status (normoglycaemia, impaired fasting glucose, new-onset type 2 diabetes, type 2 diabetes with a duration of less than 5 years, and type 2 diabetes with a duration of 5 years or more), hypertension, chronic kidney disease, and dyslipidaemia, using likelihood ratio tests. 4 234 415 individuals who underwent the national health examination in 2009 were deemed eligible for inclusion. We excluded 1 612 819 individuals on the basis of age, triglyceride concentration, missing variables, or having dementia at baseline. We identified 2 621 596 participants aged 40 years and older (1 305 556 men and 1 316 040 women) who underwent the national health examination and followed them up until the date of any incident of dementia or the end of the study period of Dec 31, 2020. During a median follow-up of 10·3 years (IQR 10·1-10·6), 146 991 (5·6%) participants developed all-cause dementia, 117 739 (4·5%) developed Alzheimer's disease, and 14 536 (0·6%) developed vascular dementia. The risk of dementia increased progressively with higher remnant-C concentrations. Compared with the lowest quartile of remnant-C (quartile 1), HRs in the highest quartile (quartile 4) were 1·11 (95% CI 1·09-1·13) for all-cause dementia, 1·11 (1·08-1·13) for Alzheimer's disease, and 1·15 (1·09-1·21) for vascular dementia. Subgroup analyses revealed that the risk of dementia associated with high remnant-C concentrations was higher in middle-aged people aged 40-59 years than in older people. The risk of dementia associated with high concentrations of remnant-C was notably more pronounced in individuals with diabetes compared with those without diabetes, and the risk increased steeply with a longer duration of diabetes. Results showed that higher remnant-C concentrations were independently associated with increased risks of all-cause dementia, Alzheimer's disease, and vascular dementia. More research is needed to determine the mechanisms underlying this finding. Monitoring and managing higher concentrations of remnant-C might have important implications for reducing the risk of dementia. None.

Cost-effectiveness of hospital-based treatment compared with community treatment centres: an analysis of Korea National Health Insurance claims data

ObjectivesWe compared the cost-effectiveness of hospital-based treatment and that of community treatment centres (CTCs).DesignWe performed statistical analysis to compare the expenses incurred by COVID-19 patients who received hospital care with...

Regular HbA1c examination and health outcomes in adult patients with type 2 diabetes in South Korea: A retrospective cohort study.

Concerns have been raised about the effectiveness of using process-centered indicators to assess the quality of diabetes care in Korea. This study aims to examine the factors influencing the performance of regular HbA1c testing and to explore its association with health outcomes, including hospitalization and mortality. We utilized a retrospective cohort design with a 4-year follow-up period, involving 159,452 adult patients newly diagnosed with type 2 diabetes (E11 in International Classification of Diseases, 10th Edition) in 2011. We established a national population database by merging the Korea National Health Insurance (KNHI) claims database and the KNHI Qualification Database of South Korea. The proportion of diabetic patients who underwent regular HbA1c testing at least once a year in the first 3 years was determined to be 33.8%. In comparison, patients who did not receive regular tests during the same period exhibited significantly increased odds of hospitalization (diabetes/CVD/renal, OR, 1.23, 95% CI, 1.12-1.34; diabetes, OR, 1.36, 95% CI, 1.17-1.57). Additionally, this nonpatient group experienced a higher risk of mortality (OR: 1.56, 95% CI: 1.36-1.80). This study supports the positive impact of regular HbA1c testing on health outcomes for individuals with type 2 diabetes. To increase the current 33% rate of regular HbA1c testing, developing patient-customized management policies is essential. Priority should be given to diabetic patients aged 65 or older, living in rural areas, and those belonging to low-income families (medical aid).

P-754 Association between ovarian hyperstimulation syndrome and adverse obstetric and neonatal outcomes in Korea: a nationwide health insurance database study

Abstract Study question Does OHSS affect maternal and neonatal outcomes in perinatal life? Summary answer OHSS is associated with an increased risk of postpartum hemorrhage, large birth weight, neonatal respiratory distress syndrome, and intraventricular hemorrhage. What is known already Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic condition caused by ovulation induction. Golan et al.(1989)’s clinical staging system categorizes OHSS into mild, moderate, and severe based on the clinical characteristics. Among them, severe OHSS is considered potentially fatal and requires hospitalization. In 2021, a systematic review of 3,303 pregnant patients with OHSS and 89,720 pregnant patients without OHSS, drawn from 13 studies, revealed a notable impact of OHSS on preterm birth. However, owing to the characteristics of spontaneous resolution in the relatively early stages of pregnancy, no large-scale study has confirmed the OHSS and pregnancy outcomes. Study design, size, duration This retrospective study utilized a combined dataset from two primary sources: the Korea National Health Insurance (KNHI) claims database and the National Health Screening Program for Infants and Children (NHSP-IC) database. We identified all women who delivered between January 1, 2012, and December 31, 2020 from KNHI claims database. Pregnancy outcomes including preterm birth and PPH were identified from NHSP-IC database and KNHI claims database, respectively. Participants/materials, setting, methods We enrolled all women who delivered between January 1, 2012, and December 31, 2020 (N = 3,446,520). Women diagnosed with multiple pregnancy or had missing data were excluded (N = 2,565,461). The participants were divided into three groups according to the presence or absence of an ovarian hyperstimulation diagnosis code (ICD-10 code N981) and hospitalization within 3 months before pregnancy: non-OHSS group (N = 2,562,562), mild-to-moderate OHSS group (N = 2,293), severe OHSS group (N = 606). Main results and the role of chance In this study, mothers in the ovarian hyperstimulation group had a younger age and a higher rate incidence of primiparity and cesarean section. In the ovarian hyperstimulation group, a significantly high proportion of patients was diagnosed with pre-pregnancy hypertension or diabetes mellitus and gestational hypertension or gestational diabetes. The risk of postpartum hemorrhage was 38.2% higher in the mild-to-moderate OHSS group than in the non-OHSS group (adjusted odds ratio (aOR): 1.382, 95% confidence interval (CI): 1.223–1.562). No difference was found in the average birth weight of newborns according to the presence or absence of OHSS. However, the risk of macrosomia was elevated by 62.4% in the severe OHSS group (aOR: 1.624, 95% CI: 1.168–2.259) than the non-OHSS group. The mild-to-moderate OHSS group had a 36.8% higher risk of respiratory distress syndrome compared with the non-OHSS group (aOR: 1.368, 95% CI: 1.149–1.629). The mild-to-moderate OHSS group had a 2.697-fold increased risk of intraventricular hemorrhage compared with the non-OHSS group (aOR: 2.697, 95% CI: 1.338–5.437). Limitations, reasons for caution A limitation lies in the unknown details of the controlled ovarian stimulation protocol, type and dose of gonadotrophin used, hormone concentration, and embryo transfer method used due to the data structure. Despite the potential variations in the causes of hospitalization, hospitalized patients were classified into the severe OHSS group. Wider implications of the findings Although OHSS occurs during early pregnancy, further research is required to determine its long-term effects. Especially, if the incidence of IVH is significantly higher in the OHSS group, particularly among uncommon full-term neonates, further studies are warranted. Trial registration number Not Applicable

Attention-deficit/hyperactivity disorder and subsequent diagnoses of major psychiatric disorders: a nationwide population-based study.

We evaluated the risk of being diagnosed with various psychiatric disorders after an attention-deficit/hyperactivity disorder (ADHD) diagnosis using data from South Korea's National Health Insurance Service from 2002 to 2019, which covers approximately 97% of the country's population. ADHD and control groups were selected after propensity score matching was performed for individuals diagnosed with ADHD and their age- and sex-matched counterparts from the general population. Comorbid psychiatric disorders included depressive disorder, bipolar disorder, tic disorder, and schizophrenia. The incidence of newly diagnosed psychiatric disorders was compared between the groups. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated and adjusted for ADHD medication prescription. After matching, 353,898 individuals were assigned to each of the two groups. Compared to the control group, the ADHD group showed a significantly higher risk of being subsequently diagnosed with depressive disorder, bipolar disorder, schizophrenia, and tic disorder. The onset age of depressive disorder, bipolar disorder, and schizophrenia in the ADHD group was 16-17 years, approximately 5 years earlier than that in the control group. The risk for depression was the highest in individuals with high income levels, and that for schizophrenia was the highest among rural patients. The median length of the follow-up time until the diagnosis of each comorbid psychiatric disorder was 7.53, 8.43, 8.53, and 8.34 years for depressive disorder, bipolar disorder, schizophrenia, and tic disorder, respectively. Individuals with ADHD had an overall higher risk of being diagnosed with subsequent psychiatric disorders than did the controls. Hence, they should be carefully screened for other psychiatric symptoms from an early age and followed up for an extended duration, along with appropriate interventions for ADHD symptoms, including psychosocial treatments and educational approaches.

The Impact of Transcatheter Aortic Valve Implantation on Health Care Costs and Clinical Outcomes Based on Frailty Risk: A Nationwide Cohort Analysis

BackgroundTranscatheter aortic valve implantation (TAVI) is preferred for treating severe aortic stenosis in older, frail populations, yet the impact of frailty on economic and clinical outcomes of TAVI is not well studied. MethodsThis retrospective cohort study included 2175 TAVI patients from 2015 to 2019, using Korea's National Health Insurance Service database, stratifying patients into low, intermediate, and high-frailty groups, using the Hospital Frailty Risk Score (HFRS). Health care costs, admissions, and total length of hospitalization were analyzed using Wilcoxon-rank test 12 months pre- and post-TAVI. Composite endpoint of death, stroke, and major bleeding, with individual outcomes, were compared using χ2 tests and Kaplan-Meier analysis. ResultsMean age was 80.2 years, and 47.3% were male; 747 (34.3%) were low frailty, 1159 (53.3%) were moderate frailty, and 269 (12.4%) were high frailty. After TAVI, medical costs decreased in the intermediate- (pre-TAVI: 2,269,000 KRW [$1668 USD], post-TAVI: 1,607,000 KRW [$1181 USD]; P < 0.001) and high-frailty groups (pre-TAVI: 3,949,000 KRW [$2904 USD], post-TAVI: 2,188,000 KRW [$1609 USD]; P < 0.001). All frailty groups had shorter length of hospital stay post-TAVI (26 to 21 days in the low-frailty, 44 to 31 days in the intermediate-frailty, and 65 to 41 days in the high-frailty group; all P <0.001). The composite outcome was higher in the frailer groups (27.8% in the low-frailty vs 31.5% in the intermediate-frailty vs 37.9% in the high-frailty group; P = 0.008). All groups showed comparable rates of cardiovascular death, stroke, or bleeding. ConclusionsTAVI is clinically viable and cost-saving treatment option for frail patients with severe aortic stenosis.

Machine learning analysis with population data for prepregnancy and perinatal risk factors for the neurodevelopmental delay of offspring

Neurodevelopmental disorders (NDD) in offspring are associated with a complex combination of pre-and postnatal factors. This study uses machine learning and population data to evaluate the association between prepregnancy or perinatal risk factors and the NDD of offspring. Population-based retrospective cohort data were obtained from Korea National Health Insurance Service claims data for 209,424 singleton offspring and their mothers who gave birth for the first time in 2007. The dependent variables were motor development disorder (MDD), cognitive development disorder (CDD) and combined overall neurodevelopmental disorder (NDD) from offspring. Seventeen independent variables from 2002 to 2007 were included. Random forest variable importance and Shapley Additive Explanation (SHAP) values were calculated to analyze the directions of its associations with the predictors. The random forest with oversampling registered much higher areas under the receiver-operating-characteristic curves than the logistic regression of interaction and non-linearity terms, 79% versus 50% (MDD), 82% versus 52% (CDD) and 74% versus 50% (NDD). Based on random forest variable importance, low socioeconomic status and age at birth were highly ranked. In SHAP values, there was a positive association between NDD and pre- or perinatal outcomes, especially, fetal male sex with growth restriction associated the development of NDD in offspring.

Cranial Nerve Palsy and Risk of Kidney Cancer: A Nationwide Population-Based Study.

Background and Objective: Understanding whether cranial nerve palsy (CNP) acts as an independent risk factor for kidney cancer could have important implications for patient care, early detection, and potentially the development of preventive strategies for this type of cancer in individuals with CNP. This study aimed to examine the risk of kidney cancer following the onset of ocular motor CNP and assess whether CNP could be considered an independent risk factor for kidney cancer. Materials and Methods: A population-based cohort study was conducted using data from the National Sample Cohort (NSC) database of Korea's National Health Insurance Service which was collected from 2010 to 2017. Follow-up was until kidney cancer development, death, or 31 December 2018. Cox proportional hazard regression analysis was performed to determine hazard ratios (HRs) for kidney cancer according to CNP status. Participants aged 20 years or more diagnosed with CNP from 2010 to 2017 were included. Exclusions comprised individuals with specific pre-existing conditions, inability to match a control group, and missing data, among others. CNP patients were age-sex matched in a 1:5 ratio with control cases. The primary outcome was incidence of kidney cancer during the follow-up period. Results: This study comprised 118,686 participants: 19,781 in the CNP group, and 98,905 in the control group. Compared to the control group, participants with CNP had a higher risk of kidney cancer (adjusted HR in model 4, 1.599 [95% CI, 1.116-2.29]). After a 3-year lag period, the CNP group had a significantly higher risk (adjusted HR in model 4, 1.987 [95% CI, 1.252-3.154]). Conclusions: Ocular motor CNP may be an independent risk factor for kidney cancer, as indicated by a higher incidence of kidney cancer in CNP patients. Further research is needed to elucidate the underlying mechanisms and explore potential preventive measures for kidney cancer in patients with ocular motor CNP.

Aspirin versus clopidogrel as a combination therapy with direct oral anticoagulant after coronary stent implantation in patients with atrial fibrillation

Abstract Background Patients with atrial fibrillation (AF) who undergo percutaneous coronary intervention (PCI) are recommended to receive dual antithrombotic therapy including an antiplatelet agent and direct anticoagulants (DOAC). We compared the effectiveness between aspirin and clopidodgrel for a combination therapy with DOAC in this population. Methods We analyzed patient data from the Korea National Health Insurance Service. A total of 9,157 patients with AF who received dual antithrombotic therapy after PCI were included. Patients were classified into the aspirin group and clopidogrel group, and 1:1 propensity score matching (PSM) was performed. The primary ischemic endpoint was a composite of cardiovascular death, myocardial infarction, stroke, or systemic thromboembolism. A major bleeding event was defined as a bleeding event requiring hospitalization. Results After PSM, there were each 2,882 patients each in the aspirin and clopidogrel group. The incidence of the primary ischemic endpoint was similar in the two groups (22.8% vs. 21.8%, in the aspirin and clopidogrel group, hazard ratio [HR] for clopidogrel group: 0.909, 95% confidence interval [CI] 0.815 – 1.014). The incidence of each component of ischemic endpoint did not differ significantly between the two groups. All-cause mortality was increased in the clopidogrel group (HR 1.301, 95% CI 1.000 – 1.692). There was no significant difference in major bleeding events (HR 0.942, 95% CI 0.789 – 1.126). Conclusions For a dual antithrombotic therapy in patients with AF who had undergone PCI, aspirin and clopidogrel did not differ in terms of ischemic outcomes, but the use of aspirin was associated with slightly lower all-cause mortality.

#2414 Hypertension resolution after kidney transplantation is associated with better kidney transplant outcomes in patients with pre-transplant hypertension

Abstract Background and Aims Hypertension is prevalent in patients with advanced chronic kidney disease (CKD), and kidney transplantation (KT) can potentially improve hypertension. Although hypertension is expected to be resolved after KT in many recipients with pre-transplant hypertension, little is known about the hypertension resolution rate and its prognostic role in KT outcomes. Method We retrospectively identified KT recipients (between 2006 and 2015) who had pre-transplant hypertension using Health Insurance Review &amp; Assessment Service and Korea National Health Insurance System. The recipients were categorized into two groups based on their post-KT hypertension status: “persistent hypertension” and “resolved hypertension”. Cox proportional hazard analyses were performed to assess the risk of death-censored graft failure and all-cause mortality with adjusting various clinical, immunological risk factors, and socioeconomic status. Results Among 11,342 KT recipients with pre-transplant hypertension, 8,233 (73%) remained hypertensive, while 3,109 (27%) experienced hypertension resolution after KT. Recipients with resolved hypertension had lower rates of delayed graft function and major comorbidities, including diabetes mellitus, ischemic heart disease, and stroke compared to recipients who remained hypertensive. After adjusting for multiple covariates, the resolved hypertension group had 0.59-fold (95% confidence interval [CI] 0.49–0.73) lower risk for graft failure and 0.59-fold (95% CI 0.48–0.73) lower risk for all-cause mortality compared to the persistent hypertension group. Subgroup analyses revealed that the protective effect of resolved hypertension on graft survival was more pronounced in females (P for interaction = 0.045), and on overall survival was weaker in recipients with diabetes (P for interaction = 0.033). Conclusion A significant proportion of patients experienced hypertension resolution after KT, which is associated with improved graft survival and overall patient survival. The post-KT hypertension status can be used as a prognostic indicator for predicting better outcomes in KT recipients with pre-transplant hypertension.

Risk of Secondary Malignancies After Multiple Myeloma: A Nationwide Case-Control Cohort Study

IntroductionIn light of improved survival rates among multiple myeloma (MM) survivors, we sought to assess their risk of secondary malignancies compared to the general population. Materials and MethodsThis nationwide population-based case-control cohort study utilized the Korea National Health Insurance Service (KNHIS) database incorporating data from 2009 to 2020. We analyzed a total of 7348 patients diagnosed with MM in the case cohort. We selected a control group of 29,351 individuals from the general population without MM, employing a 1:4 propensity score matching approach. Matching criteria included age, sex, and comorbidities to ensure a balanced and reliable comparison. ResultsThe cumulative incidence of any secondary malignancy was significantly higher in the case cohort than the control cohort (Hazard ratio [HR] 1.576, 95% confidence interval [CI], [1.381-1.798]). Hematologic malignancy risk was notably higher in the case cohort (HR 8.026, 95% CI, [5.402-11.924]), especially therapy-related myeloid neoplasms (t-MN) (HR 12.063, 95% CI, [6.839-21.278]). No significant difference was shown in nonhematologic malignancy incidence. In subgroup analysis, transplant-eligible MM patients had a significantly higher incidence of any secondary malignancy (HR 1.104, 95% CI, [1.003-1.214]) than transplant-ineligible patients. The incidence of secondary malignancy in MM patients in the lenalidomide-available era was not significantly increased compared to the prelenalidomide era. ConclusionWhile hematologic malignancies, particularly t-MN, are significantly elevated in MM patients compared to general population, nonhematologic malignancies do not appear to be significantly elevated.

Secular trends in the incidence and treatment patterns of primary hyperparathyroidism in Korea: a nationwide cohort study.

Data on epidemiology and secular trend in primary hyperparathyroidism (PHPT) in adults are relatively limited in Asian countries. This study aims to provide an overview of the secular trends in incidence, clinical characteristics, and treatment patterns of PHPT in South Korea. We used Korea's National Health Insurance Claim database (2005-2020) to identify newly diagnosed PHPT cases. Individuals with age below 19, fewer than 2 E21.0 diagnoses, fewer than 2 PTH measurements, secondary hyperparathyroidism, undergoing dialysis or kidney transplantation within a year of diagnosis, parathyroidectomy (PTX) within a year prior to the diagnosis code, and diagnosis of multiple endocrine neoplasm or parathyroid carcinoma were excluded from the analysis. A total of 6837 patients with PHPT (PTX, n = 2989; non-surgery, n = 3848) were compared with 1:10 age- and sex-matched controls (n = 68 370). The mean age of patients with PHPT was 56.0years, with 77.4% being women. The annual incidence of PHPT increased from 0.23/100 000 persons in 2005 to 1.75 in 2020, with higher rate in women than in men. Compared with 2005-2010 (n = 675), the number of newly diagnosed PHPT cases increased up to 3.1-fold (n = 2119) in 2011-2015 and 6.0-fold (n = 4043) in 2016-2020 periods. Among all patients with PHPT, 43.7% of patients underwent PTX, with decrement of proportion of bilateral surgery among PTX group across time (11.9% in 2005-2010 to 8.9% in 2016-2020, P for trend .033). Among all patients with PHPT, non-surgery group increased from 41.6% in 2005-2010 to 58.0% in 2016-2020 (P for trend <.001). Patients with PHPT had higher odds of osteoporosis (odds ratio [OR] 7.03), renal stones (OR 10.55), chronic kidney diseases (OR 7.42), and cardiovascular, metabolic, and neurological conditions after adjustment for comorbidity index. In summary, the incidence of PHPT increased from 2005 to 2020 with predominance of non-surgical treatment, which calls for research focus on improving non-surgical management.

Clinical Implications of Polypharmacy for Patients with New-Onset Atrial Fibrillation Based on Real-World Data: Observations from the Korea National Health Insurance Service Data.

Polypharmacy is commonly observed in atrial fibrillation (AF) and is associated with poorer clinical outcomes. Our study aimed to elucidate the polypharmacy prevalence, its associated risk factors, and its relationship with adverse clinical outcomes using a 'real-world' database. This study included 451,368 subjects without prior history of AF (median age, 54 [interquartile range, 48.0-63.0] years; 207,748 [46.0%] female) from the Korea National Health Insurance Service-Health Screening (NHIS-HealS) database between 2002 and 2013. All concomitant medications prescribed were collected, and the intake of five or more concomitant drugs was defined as polypharmacy. During the follow-up, all-cause death, major bleeding events, transient ischemic attack (TIA) or ischemic stroke, and admission due to worsened heart failure were recorded. Based on up to 7.7 (6.8-8.3) years of follow-up and 768,306 person-years, there were 12,241 cases of new-onset AF identified. Among patients with new-onset AF (40.0% females, median age 63.0 [54.0-70.0] years), the polypharmacy prevalence was 30.9% (3784). For newly diagnosed AF, factors, such as advanced age (with each increase of 10 years, odds ratios (OR) 1.32, 95% confidence interval (CI) 1.26-1.40), hypertension (OR 4.00, 95% CI 3.62-4.43), diabetes mellitus (OR 3.25, 95% CI 2.86-3.70), chronic obstructive pulmonary disease (COPD) (OR 3.00, 95% CI 2.51-3.57), TIA/ischemic stroke (OR 2.36, 95% CI 2.03-2.73), dementia history (OR 2.30, 95% CI 1.06-4.98), end-stage renal disease (ESRD) or chronic kidney disease (CKD) (OR 1.97, 95% CI 1.38-2.82), and heart failure (OR 1.95, 95% CI 1.69-2.26), were found to be independently correlated with the incidence of polypharmacy. Polypharmacy significantly increased the incidence and risk of major bleeding (adjusted hazard ratio (aHR) 1.26, 95% CI 1.12-1.41). The study observed a statistically significant increase in the incidence of all-cause mortality, however, the risk for all-cause mortality elevated but did not show significance (aHR 1.11, 95% CI 0.99-1.24). The risk of stroke and admission for heart failure did not change with polypharmacy. In our investigation using data from a nationwide database, polypharmacy was widespread in new-onset AF population and was related to major bleeding events. However, polypharmacy does not serve as an independent risk factor for adverse outcomes, with exception of major bleeding event. For AF patients, ensuring tailored medication for comorbidities as well as reducing polypharmacy are essential considerations.

Risk of urolithiasis associated with allopurinol versus benzbromarone among patients with gout: a population-based cohort study.

To compare the risk of urolithiasis in gout patients initiating allopurinol, a xanthine oxidase inhibitor, vs benzbromarone, a uricosuric. Using the 2011-20 Korea National Health Insurance Service database, we conducted a cohort study on gout patients initiating allopurinol vs benzbromarone as the first-line urate-lowering treatment. The primary outcome was a new onset urinary stone. The secondary outcome was a stone requiring intervention. We estimated hazard ratios (HRs) and 95% CIs using Cox proportional hazard models with a 5:1 ratio propensity-score matching on >80 variables. Subgroup analyses were done by age, sex, thiazide use and cardiovascular risk. 61 300 allopurinol initiators PS-matched on 12 260 benzbromarone initiators were included (mean age 59 years, 79% male). During a mean follow-up of 322 days, 619 urolithiasis cases occurred with an incidence rate of 0.87 per 100 person-years in allopurinol and 1.39 in benzbromarone initiators, showing a HR of 0.64 (95% CI, 0.51-0.80). Approximately 44% of urinary stones required intervention with a HR of 0.61 (95% CI, 0.43-0.88). The lower risk associated with allopurinol compared with benzbromarone persisted across subgroups but was greater in the high than non-high cardiovascular risk subgroup (P for interaction = 0.02). This population-based cohort study found that allopurinol compared with benzbromarone was associated with a substantially lower risk of urolithiasis particularly in the presence of the high cardiovascular risk. This finding provides important safety information for clinicians' decision-making on urate-lowering treatments of different mechanisms of action.