LC : Factors Associated with Significant Liver Stiffness Diagnosed by Transient Elastography in Apparently Healthy Subjects

( Seng Chan You ),( Kwang Joon Kim ),( Seung Up Kim ),( Beom Kyung Kim ),( Jun Yong Park ),( Do Young Kim ),( Sang Hoon Ahn ),( Kwang Hyub Han ) 대한간학회 2013 춘·추계 학술대회 (KASL) Vol.2013 No.1

Background: Transient elastography(TE) has emerged as a promising non-invasive tool for assessing degree of fibrosis by scoring liver stiffness(LS) in chronic liver disease. However, Studies on the prevalence of significant liver fibrosis and its predictors in apparently healthy subjects have been rarely investigated. The aim of this study was to identify factors related to the presence of significant liver fibrosis defined using TE in apparently healthy subjects. Methods: A total of 159 subjects who underwent medical healthy check-up between January 2012 and July 2012 were prospectively recruited. Subjects with chronic viral hepatitis were excluded. Significant liver fibrosis was defined as LS value >7 kPa. Results: The mean age of the study population(87 men) was 56.0 year. Mean body mass index (BMI) was 24.3kg/m2. Among the study subjects, 11(8.0%) showed significant fibrosis. BMI, alanine aminotransferase(ALT), homeostasis model assessment of insulin resistance(HOMA-IR), intimal media thickness(IMT), number of calcified carotid plaques, and visceral fat area on computed tomography were significantly higher in subjects with significant fibrosis(24.1 vs. 27.5kg/m2, 22.2 vs. 32.3IU/L, 1.7 vs. 2.9, 0.7 vs. 1.4mm, 0.4 vs. 1.5, and 107.2 vs. 171.5cm2, respectively; all P<0.05). After adjusting these variables, BMI (Odd ratio[OR] 1.487; 95% confidence interval[CI] 1.009-2.193, P=0.045), ALT(OR 1.078, 95% CI 1.015-1.145, P=0.014), IMT(OR 3.244, 95% CI 1.140-9.234, P=0.027), and the number of calcified carotid plaques(OR 1.787, 95% CI 1.055-3.026, P=0.031) were selected as independent predictors of the presence of significant fibrosis. Conclusions: Despite no evidences of chronic liver disease, the prevalence of significant liver fibrosis was quite high in apparently healthy subjects, when assessed using TE. Higher BMI and ALT level, thicker IMT, and higher number of calcified carotid plaques were independently associated with the presence of significant fibrosis. Our results can be helpful to identify the subjects who are at risk of the presence of asymptomatic significant liver fibrosis.

Comparison of First-Line Dual Combination Treatments in Hypertension: Real-World Evidence from Multinational Heterogeneous Cohorts

Seng Chan You,Sungjae Jung,Joel N. Swerdel,Patrick B. Ryan,Martijn J. Schuemie,Marc A. Suchard,Seongwon Lee,Jaehyeong Cho,George Hripcsak,Rae Woong Park,Sungha Park 대한심장학회 2020 Korean Circulation Journal Vol.50 No.1

Background and Objectives: 2018 ESC/ESH Hypertension guideline recommends 2-drug combination as initial anti-hypertensive therapy. However, real-world evidence for effectiveness of recommended regimens remains limited. We aimed to compare the effectiveness of first-line anti-hypertensive treatment combining 2 out of the following classes: angiotensin-converting enzyme (ACE) inhibitors/angiotensin-receptor blocker (A), calcium channel blocker (C), and thiazide-type diuretics (D). Methods: Treatment-naïve hypertensive adults without cardiovascular disease (CVD) who initiated dual anti-hypertensive medications were identified in 5 databases from US and Korea. The patients were matched for each comparison set by large-scale propensity score matching. Primary endpoint was all-cause mortality. Myocardial infarction, heart failure, stroke, and major adverse cardiac and cerebrovascular events as a composite outcome comprised the secondary measure. Results: A total of 987,983 patients met the eligibility criteria. After matching, 222,686, 32,344, and 38,513 patients were allocated to A+C vs. A+D, C+D vs. A+C, and C+D vs. A+D comparison, respectively. There was no significant difference in the mortality during total of 1,806,077 person-years: A+C vs. A+D (hazard ratio [HR], 1.08; 95% confidence interval [CI], 0.97−1.20; p=0.127), C+D vs. A+C (HR, 0.93; 95% CI, 0.87−1.01; p=0.067), and C+D vs. A+D (HR, 1.18; 95% CI, 0.95−1.47; p=0.104). A+C was associated with a slightly higher risk of heart failure (HR, 1.09; 95% CI, 1.01−1.18; p=0.040) and stroke (HR, 1.08; 95% CI, 1.01−1.17; p=0.040) than A+D. Conclusions: There was no significant difference in mortality among A+C, A+D, and C+D combination treatment in patients without previous CVD. This finding was consistent across multi-national heterogeneous cohorts in real-world practice.

Establishment of an International Evidence Sharing Network Through Common Data Model for Cardiovascular Research

Seng Chan You,Seongwon Lee,Byungjin Choi,Rae Woong Park 대한심장학회 2022 Korean Circulation Journal Vol.52 No.12

A retrospective observational study is one of the most widely used research methods in medicine. However, evidence postulated from a single data source likely contains biases such as selection bias, information bias, and confounding bias. Acquiring enough data from multiple institutions is one of the most effective methods to overcome the limitations. However, acquiring data from multiple institutions from many countries requires enormous effort because of financial, technical, ethical, and legal issues as well as standardization of data structure and semantics. The Observational Health Data Sciences and Informatics (OHDSI) research network standardized 928 million unique records or 12% of the world’s population into a common structure and meaning and established a research network of 453 data partners from 41 countries around the world. OHDSI is a distributed research network wherein researchers do not own or directly share data but only analyzed results. However, sharing evidence without sharing data is difficult to understand. In this review, we will look at the basic principles of OHDSI, common data model, distributed research networks, and some representative studies in the cardiovascular field using the network. This paper also briefly introduces a Korean distributed research network named FeederNet.

Degree of Hepatic Fibrosis Assessed Using Transient Elastography is Independently Related with Coronary Artery Calcification in Nonalcoholic Liver Disease

Seng Chan You,Kwang Joon Kim,Seung Up Kim,Beom Kyung Kim,Jun Yong Park,Do Young Kim,Sang Hoon Ahn,Kwang-Hyub Han 한국간담췌외과학회 2014 한국간담췌외과학회 학술대회지 Vol.2014 No.4

Observational Research Based on Common Data Model Network

( Seng Chan You ) 대한결핵 및 호흡기학회 2023 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.136 No.0

Poster Session:PS 0221 ; Gastroenterology : Degree of Hepatic Fibrosis Assessed Using Transient Elastography is Independently Related with Coronary Artery Calcifi cation in Nonalcoholic Liver Disease

( Seng Chan You ),( Kwang Joon Kim ),( Seung Up Kim ),( Beom Kyung Kim ),( Jun Yong Park ),( Do Young Kim ),( Sang Hoon Ahn ),( Kwang Hyub Han ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Nonalcoholic fatty liver disease (NAFLD) has a close relationship with coronary atherosclerosis. This study aimed to investigate factors infl uencing on coronary artery calcifi cation (CAC) in patients with NAFLD. Methods: Between January 2012 and March 2014, a total of 285 asymptomatic subjects without chronic viral hepatitis, excessive alcohol consumption, and known liver or ischemic heart disease who underwent comprehensive medical health checkup including Doppler echocardiography, transient elastography (TE), carotid Doppler ultrasound, fat computed tomography (CT), and coronary CT were recruited. Of these, 144 subjects had NAFLD which was defi ned as controlled attenuation parameter (CAP) value of TE = 250 dB/m. Results: The median age of study population with NAFLD (men 94 and women 50) was 57 (interquartile [IQR], 51-64) years. 143 (49.7%) had NAFLD. Obesity, hypertriglyceridemia and higher visceral fat area on CT were independent predictors for presence of NAFLD. In NAFLD, CAC score was independently correlated with older age (ß=0.187: P=0.020), male gender (ß=0.230: P=0.005), higher liver stiffness (LS) values (ß=0.274: P<0.001), elevated ESR (ß=0.220: P=0.007), and reduced estimated glomerular fi ltration rate (eGFR) (ß=-0.220: P=0.004). Conclusions: This is the fi rst study which analyzed comprehensive metabolic and cardiovascular parameters to identify factors infl uencing CAC score in patients with NAFLD and found that higher LS values by TE, along with older age, male gender, elevated ESR, and reduced eGFR were independently correlated with CAC score in these patients. However, it should be further investigated whether TE can be incorporated into a screening strategy to identify the risk of coronary heart disease in patients with NAFLD.

Real-world incidence of endopthalmitis after intravitreal anti-VEGF injections in Korea: findings from the Common Data Model in ophthalmology

Yongseok Mun,Seng Chan You,Da Yun Lee,Seok Kim,Yoo-Ri Chung,Kihwang Lee,Ji Hun Song,Young Gun Park,Young Hoon Park,Young-Jung Roh,Se Joon Woo,Kyu Hyung Park,Rae Woong Park,Sooyoung Yoo,Dong-Jin Chang 한국역학회 2021 Epidemiology and Health Vol.43 No.-

OBJECTIVES: The aim of this study was to evaluate the real-world incidence of endophthalmitis after intravitreal anti-vascular endothelial growth factor (VEGF) injections using data from the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM). METHODS: Patients with endophthalmitis that developed within 6 weeks after intravitreal anti-VEGF injections were identified in 3 large OMOP CDM databases. RESULTS: We identified 23,490 patients who received 128,123 intravitreal anti-VEGF injections. The incidence rates of endophthalmitis were 15.75 per 10,000 patients and 2.97 per 10,000 injections. The incidence rates of endophthalmitis for bevacizumab, ranibizumab, and aflibercept (per 10,000 injections) were 3.64, 1.39, and 0.76, respectively. The annual incidence has remained below 5.00 per 10,000 injections since 2011 despite the increasing number of intravitreal anti-VEGF injections. Bevacizumab presented a higher incidence rate for endophthalmitis than ranibizumab and aflibercept (incidence rate ratio, 3.17; p=0.021). CONCLUSIONS: The incidence of endophthalmitis after intravitreal anti-VEGF injections has stabilized since 2011 despite the explosive increase in anti-VEGF injections. The off-label use of bevacizumab accounted for its disproportionately high incidence of endophthalmitis. The OMOP CDM, which includes off-label uses, laboratory data, and a scalable standardized database, could provide a novel strategy to reveal real-world evidence, especially in ophthalmology.

Genomic Common Data Model for Seamless Interoperation of Biomedical Data in Clinical Practice: Retrospective Study

Shin, Seo Jeong,You, Seng Chan,Park, Yu Rang,Roh, Jin,Kim, Jang-Hee,Haam, Seokjin,Reich, Christian G,Blacketer, Clair,Son, Dae-Soon,Oh, Seungbin,Park, Rae Woong JMIR Publications 2019 Journal of medical Internet research Vol.21 No.3

<P><B>Background</B></P><P>Clinical sequencing data should be shared in order to achieve the sufficient scale and diversity required to provide strong evidence for improving patient care. A distributed research network allows researchers to share this evidence rather than the patient-level data across centers, thereby avoiding privacy issues. The Observational Medical Outcomes Partnership (OMOP) common data model (CDM) used in distributed research networks has low coverage of sequencing data and does not reflect the latest trends of precision medicine.</P><P><B>Objective</B></P><P>The aim of this study was to develop and evaluate the feasibility of a genomic CDM (G-CDM), as an extension of the OMOP-CDM, for application of genomic data in clinical practice.</P><P><B>Methods</B></P><P>Existing genomic data models and sequencing reports were reviewed to extend the OMOP-CDM to cover genomic data. The Human Genome Organisation Gene Nomenclature Committee and Human Genome Variation Society nomenclature were adopted to standardize the terminology in the model. Sequencing data of 114 and 1060 patients with lung cancer were obtained from the Ajou University School of Medicine database of Ajou University Hospital and The Cancer Genome Atlas, respectively, which were transformed to a format appropriate for the G-CDM. The data were compared with respect to gene name, variant type, and actionable mutations.</P><P><B>Results</B></P><P>The G-CDM was extended into four tables linked to tables of the OMOP-CDM. Upon comparison with The Cancer Genome Atlas data, a clinically actionable mutation, p.Leu858Arg, in the <I>EGFR</I> gene was 6.64 times more frequent in the Ajou University School of Medicine database, while the p.Gly12Xaa mutation in the <I>KRAS</I> gene was 2.02 times more frequent in The Cancer Genome Atlas dataset. The data-exploring tool GeneProfiler was further developed to conduct descriptive analyses automatically using the G-CDM, which provides the proportions of genes, variant types, and actionable mutations. GeneProfiler also allows for querying the specific gene name and Human Genome Variation Society nomenclature to calculate the proportion of patients with a given mutation.</P><P><B>Conclusions</B></P><P>We developed the G-CDM for effective integration of genomic data with standardized clinical data, allowing for data sharing across institutes. The feasibility of the G-CDM was validated by assessing the differences in data characteristics between two different genomic databases through the proposed data-exploring tool GeneProfiler. The G-CDM may facilitate analyses of interoperating clinical and genomic datasets across multiple institutions, minimizing privacy issues and enabling researchers to better understand the characteristics of patients and promote personalized medicine in clinical practice.</P>

Perceived Risk of Re-Identification in OMOP-CDM Database: A Cross-Sectional Survey

Tak Yae Won,You Seng Chan,Han Jeong Hyun,Kim Soon-Seok,Kim Gi-Tae,Lee Yura 대한의학회 2022 Journal of Korean medical science Vol.37 No.26

Background: The advancement of information technology has immensely increased the quality and volume of health data. This has led to an increase in observational study, as well as to the threat of privacy invasion. Recently, a distributed research network based on the common data model (CDM) has emerged, enabling collaborative international medical research without sharing patient-level data. Although the CDM database for each institution is built inside a firewall, the risk of re-identification requires management. Hence, this study aims to elucidate the perceptions CDM users have towards CDM and risk management for re-identification. Methods: The survey, targeted to answer specific in-depth questions on CDM, was conducted from October to November 2020. We targeted well-experienced researchers who actively use CDM. Basic statistics (total number and percent) were computed for all covariates. Results: There were 33 valid respondents. Of these, 43.8% suggested additional anonymization was unnecessary beyond, “minimum cell count” policy, which obscures a cell with a value lower than certain number (usually 5) in shared results to minimize the liability of re-identification due to rare conditions. During extract-transform-load processes, 81.8% of respondents assumed structured data is under control from the risk of re-identification. However, respondents noted that date of birth and death were highly re-identifiable information. The majority of respondents (n = 22, 66.7%) conceded the possibility of identifier-contained unstructured data in the NOTE table. Conclusion: Overall, CDM users generally attributed high reliability for privacy protection to the intrinsic nature of CDM. There was little demand for additional de-identification methods. However, unstructured data in the CDM were suspected to have risks. The necessity for a coordinating consortium to define and manage the re-identification risk of CDM was urged.

Transvascular Implantation of an Implantable Cardioverter-Defibrillator in a Patient Who has Undergone One-and-a-Half Ventricle Repair

양필성,박제욱,이영준,김동준,Seng Chan You,박동혁,엄재선,김남균 대한심장학회 2015 Korean Circulation Journal Vol.45 No.4

Implantable cardioverter-defibrillator (ICD) therapy is acknowledged as a valid treatment method for the effective prevention of sudden cardiac death, which is a major cause of mortality in adult congenital heart disease patients. But ICD implantation by the conventional transvascular approach is not always possible in patients who have undergone palliative surgery due to congenital and structural heart disease. Here, we report a case in which an ICD was transvascularly implanted in an arrhythmogenic right ventricular cardiomyopathy patient who had undergone a one-and-a-half ventricle repair.