Article
Health Care Sciences & Services
Takeshi Emura, Marc Ditzhaus, Dennis Dobler, Kenta Murotani
Summary: Factorial analyses are a powerful nonparametric method to detect effects among multiple treatments. In this article, new methods for factorial survival analyses are developed under dependent censoring regimes. By combining existing methods with survival copula models, an appealing F-test with good performance is presented.
STATISTICAL METHODS IN MEDICAL RESEARCH
(2023)
Article
Biology
C. Czado, I Van Keilegom
Summary: We propose a new model that considers the stochastic dependence between survival time T and censoring time C, taking into account the parametric copula and marginal distributions for T and C. We provide sufficient conditions for identifying the bivariate distribution of (T, C) and check them for common copulas and marginals. We also study the estimation of the model and illustrate it with extensive simulations and analysis on a pancreatic cancer dataset.
Article
Biochemistry & Molecular Biology
Chih-Tung Yeh, Gen-Yih Liao, Takeshi Emura
Summary: This article proposes a sensitivity analysis method using the copula-graphic estimator to assess the impact of dependent censoring on a multi-gene predictor. The method is implemented in the R package compound.Cox and a web application is developed for practical use. The lung cancer dataset is used as an example.
Article
Mathematics
Mengyue Zhang, Shishun Zhao, Tao Hu, Da Xu, Jianguo Sun
Summary: This paper examines the regression analysis of current status data with informative censoring times and left truncation. An inference approach based on sieve maximum likelihood estimation (SMLE) is proposed. A copula-based approach is used to describe the relationship between the failure time of interest and the censoring time. Simulation studies suggest that the developed procedure works well in practice, and the method is applied to a real dataset derived from an AIDS cohort research.
Article
Biology
N. W. Deresa, I Van Keilegom
Summary: This paper introduces a semiparametric normal transformation model to address the potential conditional dependencies in survival data, showing the identifiability and consistency of estimators using nonparametric monotone transformation and a linear model. The proposed method is evaluated against an estimation method under a fully parametric model to assess its finite-sample performance.
Article
Mathematics
Zhiwei Bai, Hongkui Wei, Yingying Xiao, Shufang Song, Sergei Kucherenko
Summary: By using Vine copula, the joint probability density function of multidimensional variables can be decomposed into the product of marginal PDF and bivariate copula functions, transforming multidimensional dependent problems into two-dimensional dependent problems. A novel Vine copula-based approach is proposed for analyzing variance-based sensitivity measures, accurately estimating the main and total sensitivity indices of dependent input variables. Test cases and engineering examples demonstrate the accuracy and applicability of the proposed methods.
Article
Engineering, Mechanical
Pan Wang, Haihe Li, Xiaoyu Huang, Zheng Zhang, Sinan Xiao
Summary: By introducing copula functions to describe the joint probability distribution of dependent input variables, reliability-oriented sensitivity analysis can be decomposed into independent and dependent sensitivity, with a preference for bivariate copulas in practice. The vine copula model is employed to transform multivariate PDF into multiple bivariate copulas, allowing for computation of sensitivity using score functions. Numerical examples and engineering applications validate the proposed method's rationality.
JOURNAL OF MECHANICAL DESIGN
(2021)
Article
Mathematics
A. A. Abdushukurov, R. S. Muradov
Summary: The problem addressed in this article is the estimation of the conditional joint survival function using right random censored observations in the presence of covariate. Two estimators of the conditional joint survival function are proposed, and their large sample properties are studied. The authors demonstrate the asymptotic equivalence of the estimators and derive almost sure representation results. Additionally, the article presents results of asymptotic normality with convergence to the same limiting Gaussian process.
LOBACHEVSKII JOURNAL OF MATHEMATICS
(2022)
Article
Statistics & Probability
David M. Ruth, Nicholas L. Wood, Douglas N. VanDerwerken
Summary: This paper investigates the nonparametric estimation of survival function in the presence of informative right censoring and time-dependent covariates. A novel method is introduced to incorporate multiple observations per subject when estimating the survival function at different covariate values, and several competing methods are compared through simulation. The proposed method is applied to survival data from people awaiting liver transplant.
JOURNAL OF APPLIED STATISTICS
(2023)
Article
Computer Science, Artificial Intelligence
Ahmed H. Shahin, An Zhao, Alexander C. Whitehead, Daniel C. Alexander, Joseph Jacob, David Barber
Summary: Survival analysis is a valuable tool in healthcare for predicting the time to specific events. This paper introduces CenTime, a novel approach that directly estimates the time to event. The method performs well with censored data and can be easily integrated with deep learning models. Compared to standard methods, CenTime offers superior performance in predicting event time while maintaining comparable ranking performance.
MEDICAL IMAGE ANALYSIS
(2024)
Article
Statistics & Probability
Simon M. S. Lo, Ralf A. Wilke
Summary: A model without restrictions is introduced in this article for survival analysis situations where there is only interest in one risk and no information about risk dependence is available. An application to employment duration demonstrates that this model avoids sizable bias in the estimated gender effect.
JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES C-APPLIED STATISTICS
(2023)
Article
Multidisciplinary Sciences
Luis A. A. Souto Arias, Pasquale Cirillo, Cornelis W. W. Oosterlee
Summary: We propose a non-parametric estimator that combines the expectation-maximization algorithm and the reinforced urn process for bivariate left-truncated and right-censored observations. The resulting expectation-reinforcement algorithm allows for the inclusion of prior distribution, making it a Bayesian model. This new approach recovers the distribution of the truncation variables, providing further insights into biases in the sampling process, especially in prevalent cohort studies. Numerical tests using artificial and empirical datasets compare the estimators with copula models and the Kaplan-Meier estimator.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Mathematical & Computational Biology
Busola Sanusi, Jianwen Cai, Michael G. Hudgens
Summary: This paper considers the nonparametric estimation of the joint distribution of a survival time and a mark variable, where the survival time is subject to right censoring and the mark variable is only observed when the survival time is not censored. Dependent censoring is allowed for by using inverse probability of censoring weights. The proposed estimator is shown to be consistent and asymptotically normal. The finite sample behavior of the proposed methods is investigated through simulation study. Finally, the nonparametric estimator is illustrated using a recent HIV vaccine efficacy trial.
STATISTICS IN MEDICINE
(2023)
Article
Computer Science, Interdisciplinary Applications
Jingwen Song, Yifei Zhang, Yifan Cui, Ting Yue, Yan Dang
Summary: This article proposes a robust and efficient sensitivity analysis approach using Bayesian active learning technology. The AL-CDF algorithm is introduced to obtain an accurate CDF of model output with a small group of training data. The method allows for Bayesian inference and derivation of posterior variations of moment-independent sensitivity indices. The effectiveness of the approach is demonstrated through numerical examples and practical applications.
ENGINEERING WITH COMPUTERS
(2023)
Article
Engineering, Industrial
Omer Altindag, Halil Aydogdu
Summary: Renewal function and its variance function estimation problem under progressively censored data are investigated in this study. Parametric plug-in estimators are proposed with established statistical properties of consistency and asymptotic unbiasedness. The possible applications of the estimators in maintenance, warranty, and spare parts analyzes are discussed, and numerical procedures are provided for computation.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2021)
Article
Gastroenterology & Hepatology
Se Woo Park, Kyong Joo Lee, Moon Jae Chung, Jung Hyun Jo, Hee Seung Lee, Jeong Youp Park, Seung Woo Park, Si Young Song, Huapyong Kang, Eui Joo Kim, Yeon Suk Kim, Jae Hee Cho, Seungmin Bang
Summary: This study compared the clinical outcomes of UCDBS and PCDBS for distal MBO. The results showed that PCDBS had a longer stent patency, but there were no significant differences between the two groups in overall survival and stent dysfunction.
GASTROINTESTINAL ENDOSCOPY
(2023)
Article
Endocrinology & Metabolism
Hee Seung Lee, Wonjeong Chae, Min Je Sung, Jiyoung Keum, Jung Hyun Jo, Moon Jae Chung, Jeong Youp Park, Seung Woo Park, Si Young Song, Eun-Cheol Park, Chung Mo Nam, Sung-In Jang, Seungmin Bang
Summary: This study aimed to investigate the differences in incidence of pancreatic cancer between new-onset diabetes mellitus (NODM) and long-standing DM (LSDM). The results showed that the risk of pancreatic cancer was higher in the group with diabetes compared to the non-diabetes group, and the risk was higher in the NODM group than in the LSDM group, especially in men and patients in their 50s.
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM
(2023)
Article
Multidisciplinary Sciences
Hee Seung Lee, Dai Hoon Han, Kyungjoo Cho, Soo Been Park, Chanyang Kim, Galam Leem, Dawoon E. Jung, Soon Sung Kwon, Chul Hoon Kim, Jung Hyun Jo, Hye Won Lee, Si Young Song, Jun Yong Park
Summary: The study developed organoids for two ICC subtypes, which revealed distinct transcriptional profiles and potential therapeutic targets.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Joon Ho, Eunhwa Kim, Myeongjee Lee, Inkyung Jung, Young Suk Jo, Jandee Lee
Summary: The increasing prevalence of obesity has led to a rise in obesity-related diseases such as dyslipidemia and non-alcoholic fatty liver disease. This study aimed to determine whether thyroid cancer in patients with these diseases could increase the risk of other cancers.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Mi Ho Jeong, Taehwang Son, Yoo Keung Tae, Chan Hee Park, Hee Seung Lee, Moon Jae Chung, Jeong Youp Park, Cesar M. M. Castro, Ralph Weissleder, Jung Hyun Jo, Seungmin Bang, Hyungsoon Im
Summary: Cholangiocarcinoma (CCA) is a fatal disease often diagnosed at advanced stages. There is a lack of effective diagnostic methods or biomarkers for early detection of CCA. A nanoplasmonic sensing technology called FLEX is developed for sensitive and robust single extracellular vesicle (EV) analysis, which detected a wide heterogeneity of CCA-derived EVs and identified tumor markers in clinical bile samples. The FLEX assay showed better diagnostic performance than current clinical markers, offering a potential tool for early CCA diagnosis.
Article
Multidisciplinary Sciences
Annie Kim, Inkyung Jung
Summary: Class imbalance is a challenge in classification, and resampling is a common solution. However, traditional resampling methods can lead to overgeneralization. This study presents two alternative approaches to mitigate the overgeneralization problem and compares the resampling results in various scenarios.
Article
Medicine, General & Internal
Chan Min Jung, Minkyung Han, Hyung-Ju Cho, Chang-Hoon Kim, Inkyung Jung, Min-Seok Rha
Summary: The implementation of non-pharmaceutical interventions (NPIs) during the COVID-19 pandemic was found to be associated with a reduction in the incidence and treatment of chronic rhinosinusitis (CRS).
JOURNAL OF CLINICAL MEDICINE
(2023)
Article
Multidisciplinary Sciences
Woo Kyung Ryu, Jakyung Lee, Youngmok Park, Inkyung Jung, Young Ae Kang
Summary: This study investigated the incidence of nontuberculous mycobacterial (NTM) infection in patients with depression and found that it did not significantly differ from patients without depression. However, the small number of NTM infections may have underestimated the differences between the two groups.
Article
Rheumatology
H. W. Kim, E. H. Kim, M. Lee, I. Jung, S. S. Ahn
Summary: In a large Asian population, this study compared the safety data of IL-17 and TNF-alpha inhibitors for the management of severe/refractory AS, PsA, and PsO. The results showed comparable risk of cancer and serious infections between the two treatments, while IL-17 inhibitors may be advantageous for TB.
CLINICAL AND EXPERIMENTAL RHEUMATOLOGY
(2023)
Article
Multidisciplinary Sciences
Ja Ho Koo, Myeongjee Lee, Eun Hwa Kim, Hyung Jung Oh, Joon Seok Lim, Woo Jin Hyung, Hong In Yoon, Inkyung Jung, Yong Eun Chung
Summary: This retrospective study investigated the impact of repetitive exposure to intravenous iodinated contrast media on long-term renal function in patients who underwent curative surgery for gastric cancer. The study found that the frequency of CT scans using ICM slightly increased the odds of developing chronic kidney disease.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Joon Ho, Minkyung Han, Inkyung Jung, Young Suk Jo, Jandee Lee
Summary: Thyroid hormone administration has an effect on the risk of second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer, and the dose and duration of treatment are correlated with the risk.
SCIENTIFIC REPORTS
(2023)
Article
Public, Environmental & Occupational Health
Jisu Moon, Minseok Kim, Inkyung Jung
Summary: Our method focuses on improving the performance of the spatial scan statistic by optimizing the MRCS value when using the multinomial model. In public health and disease surveillance, the proposed method can be used to provide more accurate and meaningful spatial cluster detection for multinomial data, such as disease subtypes.
INTERNATIONAL JOURNAL OF HEALTH GEOGRAPHICS
(2023)
