National Health Insurance Service Claims Research Articles

Epidemiology of autoimmune liver disease in Korea: evidence from a nationwide real-world database

BackgroundAutoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are all immune-mediated chronic inflammatory liver diseases. Autoimmune liver diseases are rare, making identification and treatment difficult. To improve clinical outcomes and enhance patient quality of life, we performed an epidemiological study of autoimmune liver diseases based on real-world comprehensive data.ResultsWe used National Health Insurance Service claims data in Korea from 2005 to 2019. Patients were identified using the International Classification of Disease 10th Revision code, and rare intractable disease codes assigned according to the strict diagnostic criteria. In the AIH cohort, 8,572 (83.9%) were females and the mean age at diagnosis was 56.3 ± 14.3 years. PBC also showed female dominance (83.3%) and the mean age was 57.8 ± 12.6 years. Patients with PSC showed no sex predominance and had a mean age of 57.8 ± 21.5 years. During the study period, there were 10,212, 6,784, and 888 AIH, PBC, and PSC patients, respectively. The prevalence of AIH, PBC, and PSC in 2019 were 18.4, 11.8, and 1.5 per 100,000 population, while the corresponding incidences were 2.3, 1.4, and 0.3 per 100,000 population, respectively. Analysis of sex-age-standardized data showed that the annual prevalence of these diseases is increasing. The 10-year survival rates were 89.8%, 74.9%, and 73.4% for AIH, PBC, and PSC, respectively.ConclusionsThe number of patients with autoimmune liver disease in South Korea is increasing over time. Further research on autoimmune liver disease is needed to fulfill unmet clinical needs.

Increased Risk of Fragility Fractures in Patients with Primary Biliary Cholangitis

Abstract Large-scale studies on the risk of fragility fractures in patients with primary biliary cholangitis (PBC) are limited due to low incidence. We aimed to investigate whether PBC is associated with fragility fractures using real-world nationwide data. The Korean National Health Insurance Service claims data from 2007 to 2020 were analyzed in this population-based cohort study. Patients with PBC (n = 4951) were matched with controls (n = 19 793) using a 1:4 ratio based on age, sex, and follow-up duration. The primary outcome was fragility fracture, which comprised fractures of the vertebra, hip, distal radius, and proximal humerus. The incidence rates (IRs) and hazard ratios (HRs) were determined to assess the impact of PBC on fragility fractures. During the median follow-up period of 5.37 years, 524 patients in the PBC group had fragility fractures (IR, 18.59/1000 person-years [PYs]). After adjusting for covariates, PBC increased the risk of fragility fractures by 1.63-fold (95% confidence interval, 1.20–2.22; P = 0.002). The vertebra and hip were particularly susceptible to fracture in patients with PBC, with adjusted HRs of 1.77 and 2.23, respectively. In the subgroup analysis, the risk of fragility fracture was 2.53-fold higher in men and 1.59-fold higher in women with PBC than that in the respective matched control groups. Considering the morbidity and mortality related to fragility fractures, increasing awareness of fragility fracture risk and implementing appropriate preventive measures in patients with PBC are imperative.

Mortality Trends in Chest-Abdominal Trauma Patients Before and After the Establishment of Trauma Centers in South Korea

Purpose: We sought to assess mortality trends in chest-abdominal trauma patients, before and after the implementation of the Project Supporting Establishment of Trauma Centers (PSETC) in the Republic of Korea.Methods: Data from the National Health Insurance Service claims database between 2009 to 2017 were analyzed. Patients with chest-abdominal trauma were defined as those with relevant main diagnosis codes and claims for emergency medical management fees. Mortality and cumulative data were analyzed for each year to compare mortality before and after the establishment of regional trauma centers across Korea (2014).Results: In total, 29,127 patients were included in the analysis. While the annual incidence of trauma-related chest-abdominal injuries increased, mortalities decreased. In particular, the trauma incidence rate among patients over 50 years increased during the study period. Mortalities at trauma centers did not change year by year after the PSETC. Before and after 2014, when trauma centers operated under the PSETC, mortalities decreased [trauma cases before the PSETC; <i>n</i> = 14,321 (mortality 5.61), after the PSETC; <i>n</i> = 14,806 (mortality 4.96)].Conclusion: The number of patients treated for chest-abdominal injuries increased from 2009 to 2017 in Korea, whereas mortalities decreased over the same period.

Developing a national surveillance system for stroke and acute myocardial infarction using claims data in the Republic of Korea: a retrospective study.

Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data. We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the corresponding sampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic of Korea were estimated by applying the algorithms and weighted PPV and NPV to the 2018 National Health Insurance Service claims data. In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018. This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

Explainable artificial intelligence for predicting red blood cell transfusion in geriatric patients undergoing hip arthroplasty: Machine learning analysis using national health insurance data.

This study uses machine learning and population data to analyze major determinants of blood transfusion among patients with hip arthroplasty. Retrospective cohort data came from Korea National Health Insurance Service claims data for 19,110 patients aged 65 years or more with hip arthroplasty in 2019. The dependent variable was blood transfusion (yes vs no) in 2019 and its 31 predictors were included. Random forest variable importance and Shapley Additive Explanations were used for identifying major predictors and the directions of their associations with blood transfusion. The random forest registered the area under the curve of 73.6%. Based on random forest variable importance, the top-10 predictors were anemia (0.25), tranexamic acid (0.17), age (0.16), socioeconomic status (0.05), spinal anesthesia (0.05), general anesthesia (0.04), sex (female) (0.04), dementia (0.03), iron (0.02), and congestive heart failure (0.02). These predictors were followed by their top-20 counterparts including cardiovascular disease, statin, chronic obstructive pulmonary disease, diabetes mellitus, chronic kidney disease, peripheral vascular disease, liver disease, solid tumor, myocardial infarction and hypertension. In terms of max Shapley Additive Explanations values, these associations were positive, e.g., anemia (0.09), tranexamic acid (0.07), age (0.09), socioeconomic status (0.05), spinal anesthesia (0.05), general anesthesia (0.04), sex (female) (0.02), dementia (0.03), iron (0.04), and congestive heart failure (0.03). For example, the inclusion of anemia, age, tranexamic acid or spinal anesthesia into the random forest will increase the probability of blood transfusion among patients with hip arthroplasty by 9%, 7%, 9% or 5%. Machine learning is an effective prediction model for blood transfusion among patients with hip arthroplasty. The high-risk group with anemia, age and comorbid conditions need to be treated with tranexamic acid, iron and/or other appropriate interventions.

Incidence, prevalence, and pattern of medical service utilization of children's rare lung diseases in South Korea.

Children's rare lung diseases are a heterogeneous group of rare lung diseases with significant morbidity and mortality. There is very limited information on the incidence and prevalence of children's rare lung diseases in Asia. We investigated the nationwide incidence, prevalence, and pattern of medical service utilization of children's rare lung diseases in Korea. We studied patients who were diagnosed with rare lung diseases coded per International Statistical Classification of Diseases and Related Health Problems, 10th Edition and registered in the national rare diseases database of confirmed patients. Data was extracted from the Korean National Health Insurance Service Claims database over 2019-2021. Average incidence rate was 12.9 new cases per million children per year, and average prevalence rate was 60.2 cases per million children during the study period of 2019-2021. We found that more than 65% of new cases were diagnosed before 2 years of age. ChILD, primary ciliary dyskinesia, and cystic fibrosis were usually diagnosed after 6 years of age. Congenital airway and lung anomalies were often diagnosed before 2 years of age. Busan and Gyeongsangnam-do residents tended to visit hospitals near their place of residence, while residents of other areas tended to visit hospitals in Seoul regardless of their area of residence. We examined the epidemiology of rare lung diseases in children in South Korea. Our estimation of the incidence and prevalence could be used for sustainable health care and equitable distribution of health care resources.

Comparison of Surgical Resection and Radiofrequency Ablation in Elderly Patients with Hepatocellular Carcinoma.

The aim of this study was to examine whether the efficacy of radiofrequency ablation (RFA) and surgical resection (SR) are comparable for hepatocellular carcinoma (HCC) less than 3cm in elderly individuals aged 65years or older. We used the National Health Insurance Service claims data in Korea, which was linked with liver cancer stage data from the Central Cancer Registry of the National Cancer Center, as well as death data from the National Statistical Office. Out of the 9213 registrants, we focused on 141 patients who underwent SR and 225 patients who underwent RFA when they were 65years or older. To ensure comparability, a 1:1 propensity score (PS) matching was conducted. The SR group had lower performance status and better liver function compared to the RFA group. Tumor diameter was larger in the SR group than in the RFA group (2.1cm vs. 1.7cm), and the proportion of stage II cases was higher (62.4% vs. 33.8%). After PS matching, the mortality rate in the RFA group did not significantly differ from the SR group (HR 1.33, 95% CI 0.86-2.06, P = 0.19). Also, liver related mortality was similar between the SR and RFA group after matching (log rank P = 0.13). However, recurrence free survival was significantly longer in the SR group than RFA group before and after matching (log rank P = 0.03). In patients aged 65years or older with resectable HCC, RFA demonstrates a therapeutic effect comparable to SR.

Trend in the Incidence of Severe Partial Edentulism among Adults Using the Korean National Health Insurance Service Claim Data, 2014-2018.

Missing teeth is one of the most important indicators of oral health behavior and the result of dental caries, periodontal disease, and injuries. This study examined a trend in the incidence of severe partial edentulism (SPE) using the Korean National Health Insurance Service (KNHIS) data. Data of adults aged ≥20 years were obtained from the KNHIS for the 2014-2018 period. SPE was defined in dental information within a population with a treatment history of dental scaling as having 1 to 8 natural teeth. Crude incidence rates (CIRs) and age-standardized incidence rates (AIRs) with 95% confidence interval were calculated per 100000 persons. The Cochran Armitage trend (CAT) test and average annual percentage change were used to analyze SPE trends. The CIRs among Korean adults were from 346.29 to 391.11 in 2014-2016 and from 391.11 to 354.09 in 2016-2018. The AIRs trend statistically increased by 4.31% from 346.29 to 376.80 and decreased by 4.72% from 376.80 to 342.10. The AIRs in men increased by 4.00% and decreased by 3.01%. The AIRs in women decreased by 2.18% and increased by 2.11% (CAT; p<0.01). The AIRs by region and income also showed trends of increase and decrease. The study showed that the incidence trend of SPE increased and decreased from 2014 to 2018. This result would be able to aid in the planning of public oral health, and may also serve as fundamental data for verifying the impact of the public oral health policies implemented.

Reduced risk of gastrointestinal bleeding associated with eupatilin in aspirin plus acid suppressant users: nationwide population-based study.

Mucoprotective agents, such as eupatilin, are often prescribed to prevent gastrointestinal (GI) bleeding in addition to an acid suppressant despite the absence of a large-scale study. We evaluated the additional effect of eupatilin on the prevention of GI bleeding in both the upper and lower GI tract in concomitant aspirin and acid suppressant users using the nationwide database of national claims data from the Korean National Health Insurance Service (NHIS). An aspirin cohort was constructed using the NHIS claims data from 2013 to 2020. Patients who manifested with hematemesis, melena, or hematochezia were considered to have GI bleeding. A Cox proportional hazards regression model was used to determine the risk factors for GI bleeding associated with the concomitant use of GI drugs and other covariates among aspirin users. Overall, a total of 432,208 aspirin users were included. The concurrent use of an acid suppressant and eupatilin (hazard ratio [HR] = 0.85, p = 0.016, vs. acid suppressant only) was a statistically significant preventive factor for GI bleeding. Moreover, a more than 3-month duration (HR = 0.88, p = 0.030) of acid suppressant and eupatilin prescription (vs. acid suppressant only) was a statistically significant preventive factor for GI bleeding. Eupatilin administration for ≥ 3 months showed additional preventive effect on GI bleeding in concomitant aspirin and acid suppressant users. Thus, cotreatment with eupatilin with a duration of 3 months or longer is recommended for reducing GI bleeding among aspirin plus acid suppressant users.

The impact of physical disability on the risk of gastric cancer incidence in elderly patients with diabetes: a focus on regional disparity.

Elderly patients with type 2 diabetes mellitus (T2DM) may have a higher risk of physical disability. This study investigated the incidence of gastric cancer according to physical disability status in elderly patients with T2DM. The National Health Insurance Service claims data were used. A total of 76,162 participants aged 60 years or above, diagnosed with T2DM, were included. The association between physical disability status and gastric cancer incidence was evaluated using the Cox regression analysis. Additionally, subgroup analysis was performed according to region. A total of 9,154 (12.0%) individuals had physical disability. Gastric cancer incidence was more common in participants with physical disability (3.3%) than those without (2.4%). A higher risk of gastric cancer incidence was found in elderly T2DM patients with physical disability (Hazard Ratio (HR) 1.18, 95% Confidence Interval (95% CI) 1.04-1.34). Such tendencies were maintained regardless of region, although the effect of physical disability status on gastric cancer incidence was particularly significant in individuals residing in non-metropolitan areas (HR: 1.19, 95% CI: 1.01-1.40). Elderly patients with T2DM who had physical disability showed a higher risk of gastric cancer incidence. The findings suggest a need to monitor elderly T2DM patients with disability as they may be susceptible to difficulties in accessing cancer-related healthcare.

Early rhythm control on diabetes-related complications and mortality in patients with type 2 diabetes mellitus and atrial fibrillation

AimsWe evaluated the impact of early rhythm control (ERC) on diabetes-related complications and mortality in subjects with type 2 diabetes mellitus (T2DM) and atrial fibrillation (AF). MethodsThis observational cohort study based on the Korean National Health Insurance Service claims database from 2009 to 2016, divided newly diagnosed AF patients with T2DM into ERC or usual care groups based on receiving rhythm control treatment within 1 year of AF diagnosis. The primary outcome was ischemic stroke, and the secondary outcomes were macro/microvascular complications, and all-cause death. ResultsAmong 47,509 subjects (mean age 66.7 ± 10.5 years; 61.8 % men; mean CHA2DS2-VASc score 4.6 ± 1.8; mean follow-up 4.3 ± 2.3 years; mean DM duration 5.6 ± 4.7 years), 23.1 % received ERC, and 76.9 % did not (usual care group). ERC was associated with lower risks of ischemic stroke, macrovascular and microvascular complications, and all-cause death compared to usual care (adjusted hazard ratios [95 % confidence interval]: 0.77 [0.70–0.85], 0.79 [0.73–0.86], 0.86 [0.82–0.90], and 0.92 [0.87–0.98], p < 0.001, <0.001, <0.001, and 0.012, respectively). ConclusionsEarly rhythm control was associated with reduced risks of diabetes-related complications and mortality in subjects with T2DM and AF. Rhythm control within 1 year of AF diagnosis with proper anticoagulation should be considered to prevent adverse outcomes.

Regular laboratory testing and patient survival among patients undergoing maintenance hemodialysis: a Korean nationwide cohort study

Routine laboratory tests are regularly performed in patients undergoing maintenance hemodialysis (HD) to detect anemia, chronic kidney disease-mineral bone disorders, and cardiovascular disease. More frequent laboratory tests may be associated with better outcomes. However, there is little evidence supporting a specific monitoring interval. This study evaluated the impact of regular laboratory testing on mortality in Korean patients undergoing maintenance HD. We used HD quality assessments, and National Health Insurance Service claims data from October to December 2015. In HD quality assessment, 22 tests are recommended every 1–6 months. A total of 34,950 patients were divided into two groups based on the regularity of laboratory testing. A Cox proportional hazards model was used to assess the effects of regular laboratory tests on patient mortality during a mean follow-up duration of 53.7 months. The proportion of patients with and without regular laboratory testing was 85.6% (n = 29,914) and 14.4% (n = 5036), respectively. Patients who underwent regular laboratory testing had a longer dialysis duration, lower serum phosphorus levels and diastolic blood pressure, and higher hemoglobin and single-pool Kt/V levels than those who did not. After adjusting for demographic and clinical parameters, regular laboratory testing independently reduced mortality risk (hazard ratio, 0.90; 95% confidence interval 0.85–0.95; P < 0.001). Regular laboratory testing was associated with a decreased mortality risk among patients undergoing HD. Management of end-stage kidney disease-related complications based on laboratory tests can improve survival.

Prevalence and Medical Costs of Intellectual Disabilities and Pervasive Developmental Disorder in Korea: Based on National Health Insurance Service Claims Data from 2007 to 2019.

We aimed to investigate the annual prevalence of intellectual disabilities (ID) and autism spectrum disorder employing claims data registered in Korean National Health Insurance Service. We also estimated the annual average of medical costs incurred from these disorders using same datasets. In order to obtain the prevalence, we selected patients diagnosed with ID and pervasive and specific developmental disorders (PDD) from 2007 to 2019. The ensuing annual average of medical costs was also estimated from these patients. The annual prevalence of ID and PDD (per 100,000) between 2007 and 2019 ranged from 56.7 to 78.6 and from 22.0 to 44.6 respectively. Regarding the annual average of total medical expenditure per a patient, the expenditure of the ID group was higher than that of PDD throughout the years, as shown that the ID expenditure ranged from 769.7 to 1,501.2 US dollars as opposed to the PDD expenditure in the range of 312.5 to 570.7 US dollars. The further comparison in relation to income levels elaborated that the medical aid beneficiary group constitutes the highest one and the difference of the expenditure across the remaining income groups was not prominent although the very low group generally ranked the highest over the years. The prevalence of ID and PDD constantly increased and the same trend was displayed in ensuing health expenditures throughout the period. This implies that increasing needs exist across these patients with regards to therapeutic interventions, thereby contributing to prioritizing medical policies on national perspectives.

Long-Term Survival Prediction Model for Elderly Community Members Using a Deep Learning Method.

In an aging society, maintaining healthy aging, preventing death, and enabling a continuation of economic activities are crucial. This study sought to develop a model for predicting survival times among community-dwelling older individuals using a deep learning method, and to identify the level of influence of various risk factors on the survival period, so that older individuals can manage their own health. This study used the Korean National Health Insurance Service claims data. We observed community-dwelling older people, aged 66 years, for 11 years and developed a survival time prediction model. Of the 189,697 individuals enrolled at baseline, 180,235 (95.0%) survived from 2009 to 2019, while 9462 (5.0%) died. Using deep-learning-based models (C statistics = 0.7011), we identified various factors impacting survival: Charlson's comorbidity index; the frailty index; long-term care benefit grade; disability grade; income level; a combination of diabetes mellitus, hypertension, and dyslipidemia; sex; smoking status; and alcohol consumption habits. In particular, Charlson's comorbidity index (SHAP value: 0.0445) and frailty index (SHAP value: 0.0443) were strong predictors of survival time. Prediction models may help researchers to identify potentially modifiable risk factors that may affect survival.

The effect of the introduction of the national lung cancer screening program on short-term mortality in Korea

BackgroundSouth Korea introduced the National Lung Cancer Screening Program (NLCSP) in 2019. This study investigated the effect of the NLCSP on one-year mortality in individuals with a history of lung cancer. MethodsThis study used the 2018–2020 National Health Insurance Service claims data. The difference-in-differences approach was used to investigate the effect of participating in the NLCSP between the case and control groups before and after the intervention period. The case group included individuals aged between 54 and 74 years with a smoking history of ≥ 30 pack-years and the control group those aged between 54 and 74 years with a history of smoking of <30 pack-years and non-smokers. The pre-intervention period was from January 2018 to June 2019 and the post-intervention period from July 2019 to December 2020. ResultsThe introduction of the NLCSP was related to an overall decrease in one-year mortality (−3.21 % points, 95 % Confidence Interval (CI) −4.84 to −1.58). Specifically, this reduction was significant for lung cancer related mortality (lung cancer: −2.69 % points, 95 % CI −4.24 to −1.13). Furthermore, stronger associations were found in individuals of older age, residing in non-metropolitan areas, and who visited healthcare institutions in non-metropolitan areas. ConclusionThe findings confirm a relationship between implementation of the NLCSP and one-year mortality in eligible individuals with a history of lung cancer, which is noteworthy considering that Korea is one of the first countries to include lung cancer into the national cancer screening program.

Does Perioperative use of Bisphosphonate Affect Implant Revision Rate of Total Ankle Arthroplasty?

Category: Ankle Arthritis; Other Introduction/Purpose: It is unknown whether perioperative bisphosphonate (BP) use reduces revision rates in total ankle replacement arthroplasty (TAR) although its effect has been demonstrated to be effective in reducing revision rates in total knee or hip replacement arthroplasty. Therefore, the purpose of this study was 1) to investigate whether there is a relationship between the use of BP and the revision rate of TAR, and (2) to determine the effect of BP medication period on the revision rate of TAR. Our hypothesis was that the use of BP would lower the revision rate of TAR. Methods: We reviewed National Health Insurance Service data based on national health insurance service claim data and health care utilization, health screening, socio-demographic variables, medication history, operation codes, and mortality data for 50 million Koreans. From 2002 to 2014, 6391 of 7300 patients who underwent TAR were BP non-users, while 909 patients were BP users. The revision rate according to BP medication and co-morbidities was investigated. The Kaplan-Meier estimate and extended Cox proportional hazard model were also used. Results: The revision rate of TAR was 7.9% for BP users and 9.5% for BP non-users, which showed no significant difference (p=0.251). Implant survival over time decreased constantly. Adjusted hazard ratio for hypertension was 1.242 (p=0.017), while other co-morbidities such as diabetes had no effect on revision rate of TAR. Conclusion: We found that the perioperative BP use do not reduce the revision rate of TAR. Co-morbidities except hypertension did not affect the revision rate of TAR. More research regarding various factor affecting revision of TAR could be warranted.

Trends and Clinical Characteristics of Next-Generation Sequencing-Based Genetic Panel Tests: An Analysis of Korean Nationwide Claims Data.

In the modern era of precision medicine, next-generation sequencing (NGS) is employed for a variety of clinical purposes. The aim of this study was to investigate the trends and clinical characteristics of NGS testing in South Korea. This nationwide, population-based, retrospective cohort study examined National Health Insurance Service claims data from 2017 to 2021 for NGS and from 2008 to 2021 for gene-targeted anticancer drugs. Among the total 98,748 claims, there were 51,407 (52.1%) solid cancer panels, 30,173 (30.5%) hereditary disease panels, and 17,168 (17.4%) hematolymphoid cancer panels. The number of annual claims showed a persistent upward trend, exhibiting a 5.4-fold increase, from 5,436 in 2017 to 29,557 in 2021. In the solid cancer panel, colorectal cancer was the most common (19.2%), followed by lung cancer (18.8%). The annual claims for targeted cancer drugs have increased 25.7-fold, from 3,932 in 2008 to 101,211 in 2020. Drugs for the treatment of lung cancer accounted for 488,819 (71.9%) claims. The number of patients who received non-hereditary NGS testing has substantially increased, and among them, the count of patients prescribed targeted anticancer drugs consistently rose from 508 (13.9%) in 2017 to 2,245 (12.3%) in 2020. This study highlights the rising nationwide demand for comprehensive genetic testing for disease diagnosis and treatment following NGS reimbursement by the National Health Insurance in South Korea, in addition to the need for greater utilization of targeted anticancer drugs.

Active surveillance for adverse events of influenza vaccine safety in elderly cancer patients using self-controlled tree-temporal scan statistic analysis

Both cancer patients and the elderly are at high risk of developing flu complications, so influenza vaccination is recommended. We aimed to evaluate potential adverse events (AEs) following influenza vaccination in elderly cancer patients using the self-controlled tree-temporal scan statistic method. From a large linked database of Korea Disease Control and Prevention Agency vaccination data and the National Health Insurance Service claims data, we identified cancer patients aged over 65 who received flu vaccines during the 2016/2017 and 2017/2018 seasons. We included all the outcomes occurring on 1–84 days post-vaccination and evaluated all temporal risk windows, which started 1–28 days and ended 2–42 days. Patients who were diagnosed with the same disease during a year prior to vaccination were excluded. We used the hierarchy of ICD-10 to identify statistically significant clustering. This study included 431,276 doses of flu vaccine. We detected signals for 1 set: other dorsopathies on 1–15 days (attributable risk 16.5 per 100,000, P = 0.017). Dorsopathy is a known AE of influenza vaccine. No statistically significant clusters were found when analyzed by flu season. Therefore, influenza vaccination is more recommended for elderly patients with cancer and weakened immune systems.

Association between early preterm birth and maternal exposure to fine particular matter (PM10): A nation-wide population-based cohort study using machine learning.

Although preterm birth (PTB), a birth before 34 weeks of gestation accounts for only less than 3% of total births, it is a critical cause of various perinatal morbidity and mortality. Several studies have been conducted on the association between maternal exposure to PM and PTB, but the results were inconsistent. Moreover, no study has analyzed the risk of PM on PTB among women with cardiovascular diseases, even though those were thought to be highly susceptible to PM considering the cardiovascular effect of PM. Therefore, we aimed to evaluate the effect of PM10 on early PTB according to the period of exposure, using machine learning with data from Korea National Health Insurance Service (KNHI) claims. Furthermore, we conducted subgroup analysis to compare the risk of PM on early PTB among pregnant women with cardiovascular diseases and those without. A total of 149,643 primiparous singleton women aged 25 to 40 years who delivered babies in 2017 were included. Random forest feature importance and SHAP (Shapley additive explanations) value were used to identify the effect of PM10 on early PTB in comparison with other well-known contributing factors of PTB. AUC and accuracy of PTB prediction model using random forest were 0.9988 and 0.9984, respectively. Maternal exposure to PM10 was one of the major predictors of early PTB. PM10 concentration of 5 to 7 months before delivery, the first and early second trimester of pregnancy, ranked high in feature importance. SHAP value showed that higher PM10 concentrations before 5 to 7 months before delivery were associated with an increased risk of early PTB. The probability of early PTB was increased by 7.73%, 10.58%, or 11.11% if a variable PM10 concentration of 5, 6, or 7 months before delivery was included to the prediction model. Furthermore, women with cardiovascular diseases were more susceptible to PM10 concentration in terms of risk for early PTB than those without cardiovascular diseases. Maternal exposure to PM10 has a strong association with early PTB. In addition, in the context of PTB, pregnant women with cardiovascular diseases are a high-risk group of PM10 and the first and early second trimester is a high-risk period of PM10.

1341-P: The Improvement in Age at Mortality in Individuals with Peritoneal Dialysis Was Less Prominent in Persons with Diabetes in Korea

Backgrounds: The most prevalent underlying cause of end-stage kidney disease (ESKD) is diabetes mellitus (DM). If kidney transplantation is not possible, people with ESKD must undergo hemodialysis (HD) or peritoneal dialysis (PD). This study investigated whether the prognosis of individuals with diabetes who received PD improved recently. In addition, we analyzed the age of death and the cause of mortality to determine if there was a difference based on DM or gender from 2006 to 2018. Methods: We Used data from the National National Health Insurance database maintained by the Korean National Health Insurance Service (NHIS) and mortality records from the National Statistical Information Service (NSIS). The NHIS claims data was merged with NSIS death records from 2006 to 2018 and then analyzed. We excluded those who underwent HD or transplanting from the 93,487 cases of ESKD-related death to include only those who underwent PD. Results: A total of 11,174 deaths were documented (4,818 individuals with DM and 6,356 individuals without DM). Age at death increased by 0.11 and 0.44 years/year in persons with and without DM, respectively. Changes in mortality age were the biggest in females without DM (0.47 years/year) and lowest among men with DM (0.10 years/year). DM itself, cardio-cerebrovascular diseases, and cancer were the leading causes of death among people with DM receiving PD. Conclusions: In conclusion, this study, which utilized the entire Korean population, revealed that the death age of individuals with DM receiving PD increased marginally over 12 years, but the change was much smaller than in persons without DM. Based on these results, efforts should be made to improve the prognosis of the person with DM who underwent PD. In addition, identifying the precise cause of death and the optimal management strategy in this population would be important. Disclosure H.Kim: None. K.Son: None. S.Song: None.