International Journal of Biostatistics最新文献

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Cell Line Classification Using Electric Cell-Substrate Impedance Sensing (ECIS) 基于Cell- substrate Impedance Sensing (ECIS)的细胞系分类
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2017-10-26 DOI: 10.1515/ijb-2018-0083
Megan L. Gelsinger, Laura L. Tupper, D. Matteson
{"title":"Cell Line Classification Using Electric Cell-Substrate Impedance Sensing (ECIS)","authors":"Megan L. Gelsinger, Laura L. Tupper, D. Matteson","doi":"10.1515/ijb-2018-0083","DOIUrl":"https://doi.org/10.1515/ijb-2018-0083","url":null,"abstract":"Abstract We present new methods for cell line classification using multivariate time series bioimpedance data obtained from electric cell-substrate impedance sensing (ECIS) technology. The ECIS technology, which monitors the attachment and spreading of mammalian cells in real time through the collection of electrical impedance data, has historically been used to study one cell line at a time. However, we show that if applied to data from multiple cell lines, ECIS can be used to classify unknown or potentially mislabeled cells, factors which have previously been associated with the reproducibility crisis in the biological literature. We assess a range of approaches to this new problem, testing different classification methods and deriving a dictionary of 29 features to characterize ECIS data. Most notably, our analysis enriches the current field by making use of simultaneous multi-frequency ECIS data, where previous studies have focused on only one frequency; using classification methods to distinguish multiple cell lines, rather than simple statistical tests that compare only two cell lines; and assessing a range of features derived from ECIS data based on their classification performance. In classification tests on fifteen mammalian cell lines, we obtain very high out-of-sample predictive accuracy. These preliminary findings provide a baseline for future large-scale studies in this field.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":"16 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2017-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2018-0083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49126933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
Combinatorial Mixtures of Multiparameter Distributions: An Application to Bivariate Data 多参数分布的组合混合:在双变量数据中的应用
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2017-02-16 DOI: 10.1515/ijb-2015-0064
V. Edefonti, G. Parmigiani
{"title":"Combinatorial Mixtures of Multiparameter Distributions: An Application to Bivariate Data","authors":"V. Edefonti, G. Parmigiani","doi":"10.1515/ijb-2015-0064","DOIUrl":"https://doi.org/10.1515/ijb-2015-0064","url":null,"abstract":"Abstract: We introduce combinatorial mixtures – a flexible class of models for inference on mixture distributions whose components have multidimensional parameters. The key idea is to allow each element of the component-specific parameter vectors to be shared by a subset of other components. This approach allows for mixtures that range from very flexible to very parsimonious and unifies inference on component-specific parameters with inference on the number of components. We develop Bayesian inference and computational approaches for this class of distributions, and illustrate them in an application. This work was originally motivated by the analysis of cancer subtypes: in terms of biological measures of interest, subtypes may be characterized by differences in location, scale, correlations or any of the combinations. We illustrate our approach using publicly available data on molecular subtypes of lung and prostate cancers.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2017-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2015-0064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44982771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On Stratified Adjusted Tests by Binomial Trials 二项试验的分层校正检验
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2017-02-14 DOI: 10.1515/ijb-2016-0047
Asanao Shimokawa, E. Miyaoka
{"title":"On Stratified Adjusted Tests by Binomial Trials","authors":"Asanao Shimokawa, E. Miyaoka","doi":"10.1515/ijb-2016-0047","DOIUrl":"https://doi.org/10.1515/ijb-2016-0047","url":null,"abstract":"Abstract To estimate or test the treatment effect in randomized clinical trials, it is important to adjust for the potential influence of covariates that are likely to affect the association between the treatment or control group and the response. If these covariates are known at the start of the trial, random assignment of the treatment within each stratum would be considered. On the other hand, if these covariates are not clear at the start of the trial, or if it is difficult to allocate the treatment within each stratum, completely randomized assignment of the treatment would be performed. In both sampling structures, the use of a stratified adjusted test is a useful way to evaluate the significance of the overall treatment effect by reducing the variance and/or bias of the result. If the trial has a binary endpoint, the Cochran and Mantel-Haenszel tests are generally used. These tests are constructed based on the assumption that the number of patients within a stratum is fixed. However, in practice, the stratum sizes are not fixed at the start of the trial in many situations, and are instead allowed to vary. Therefore, there is a risk that using these tests under such situations would result in an error in the estimated variation of the test statistics. To handle the problem, we propose new test statistics under both sampling structures based on multinomial distributions. Our proposed approach is based on the Cochran test, and the difference between the two tests tends to have similar values in the case of a large number of patients. When the total number of patients is small, our approach yields a more conservative result. Through simulation studies, we show that the new approach could correctly maintain the type I error better than the traditional approach.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2017-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2016-0047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44587325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Testing Equality of Treatments under an Incomplete Block Crossover Design with Ordinal Responses 具有顺序响应的不完全块体交叉设计下处理平等性的检验
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2017-02-03 DOI: 10.1515/ijb-2016-0069
K. Lui
{"title":"Testing Equality of Treatments under an Incomplete Block Crossover Design with Ordinal Responses","authors":"K. Lui","doi":"10.1515/ijb-2016-0069","DOIUrl":"https://doi.org/10.1515/ijb-2016-0069","url":null,"abstract":"Abstract The generalized odds ratio (GOR) for paired sample is considered to measure the relative treatment effect on patient responses in ordinal data. Under a three-treatment two-period incomplete block crossover design, both asymptotic and exact procedures are developed for testing equality between treatments with ordinal responses. Monte Carlo simulation is employed to evaluate and compare the finite-sample performance of these test procedures. A discussion on advantages and disadvantages of the proposed test procedures based on the GOR versus those based on Wald’s tests under the normal random effects proportional odds model is provided. The data taken as a part of a crossover trial studying the effects of low and high doses of an analgesic versus a placebo for the relief of pain in primary dysmenorrhea over the first two periods are applied to illustrate the use of these test procedures.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2017-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2016-0069","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44878724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Bayesian Variable Selection Methods for Matched Case-Control Studies 匹配病例对照研究的贝叶斯变量选择方法
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2017-01-31 DOI: 10.1515/ijb-2016-0043
J. Asafu-Adjei, M. Tadesse, B. Coull, R. Balasubramanian, M. Lev, L. Schwamm, R. Betensky
{"title":"Bayesian Variable Selection Methods for Matched Case-Control Studies","authors":"J. Asafu-Adjei, M. Tadesse, B. Coull, R. Balasubramanian, M. Lev, L. Schwamm, R. Betensky","doi":"10.1515/ijb-2016-0043","DOIUrl":"https://doi.org/10.1515/ijb-2016-0043","url":null,"abstract":"Abstract Matched case-control designs are currently used in many biomedical applications. To ensure high efficiency and statistical power in identifying features that best discriminate cases from controls, it is important to account for the use of matched designs. However, in the setting of high dimensional data, few variable selection methods account for matching. Bayesian approaches to variable selection have several advantages, including the fact that such approaches visit a wider range of model subsets. In this paper, we propose a variable selection method to account for case-control matching in a Bayesian context and apply it using simulation studies, a matched brain imaging study conducted at Massachusetts General Hospital, and a matched cardiovascular biomarker study conducted by the High Risk Plaque Initiative.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2017-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2016-0043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46449881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Joint Model for Mortality and Hospitalization 死亡率和住院率联合模型
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2016-11-01 DOI: 10.1515/ijb-2016-0002
Yuqi Chen, Wensheng Guo, P. Kotanko, L. Usvyat, Yuedong Wang
{"title":"Joint Model for Mortality and Hospitalization","authors":"Yuqi Chen, Wensheng Guo, P. Kotanko, L. Usvyat, Yuedong Wang","doi":"10.1515/ijb-2016-0002","DOIUrl":"https://doi.org/10.1515/ijb-2016-0002","url":null,"abstract":"Abstract: Modeling hospitalization is complicated because the follow-up time can be censored due to death. In this paper, we propose a shared frailty joint model for survival time and hospitalization. A random effect semi-parametric proportional hazard model is assumed for the survival time and conditional on the follow-up time, hospital admissions or total length of stay is modeled by a generalized linear model with a nonparametric offset function of the follow-up time. We assume that the hospitalization and the survival time are correlated through a latent subject-specific random frailty. The proposed model can be implemented using existing software such as SAS Proc NLMIXED. We demonstrate the feasibility through simulations. We apply our methods to study hospital admissions and total length of stay in a cohort of patients on hemodialysis. We identify age, albumin, neutrophil to lymphocyte ratio (NLR) and vintage as significant risk factors for mortality, and age, gender, race, albumin, NLR, pre-dialysis systolic blood pressure (preSBP), interdialytic weight gain (IDWG) and equilibrated Kt/V (eKt/V) as significant risk factors for both hospital admissions and total length of stay. In addition, hospitalization admissions is positively associated with vintage.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":"12 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2016-0002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66988069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of Smoothing in Generalized Linear Mixed Models on the Estimation of Covariance Parameters for Longitudinal Data 广义线性混合模型中平滑对纵向数据协方差参数估计的影响
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2016-11-01 DOI: 10.1515/ijb-2015-0026
M. Mullah, A. Benedetti
{"title":"Effect of Smoothing in Generalized Linear Mixed Models on the Estimation of Covariance Parameters for Longitudinal Data","authors":"M. Mullah, A. Benedetti","doi":"10.1515/ijb-2015-0026","DOIUrl":"https://doi.org/10.1515/ijb-2015-0026","url":null,"abstract":"Abstract Besides being mainly used for analyzing clustered or longitudinal data, generalized linear mixed models can also be used for smoothing via restricting changes in the fit at the knots in regression splines. The resulting models are usually called semiparametric mixed models (SPMMs). We investigate the effect of smoothing using SPMMs on the correlation and variance parameter estimates for serially correlated longitudinal normal, Poisson and binary data. Through simulations, we compare the performance of SPMMs to other simpler methods for estimating the nonlinear association such as fractional polynomials, and using a parametric nonlinear function. Simulation results suggest that, in general, the SPMMs recover the true curves very well and yield reasonable estimates of the correlation and variance parameters. However, for binary outcomes, SPMMs produce biased estimates of the variance parameters for high serially correlated data. We apply these methods to a dataset investigating the association between CD4 cell count and time since seroconversion for HIV infected men enrolled in the Multicenter AIDS Cohort Study.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":"59 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2015-0026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66987691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
A Binomial Integer-Valued ARCH Model 二项整数值ARCH模型
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2016-11-01 DOI: 10.1515/ijb-2015-0051
M. Ristić, C. Weiß, Ana D Janjić
{"title":"A Binomial Integer-Valued ARCH Model","authors":"M. Ristić, C. Weiß, Ana D Janjić","doi":"10.1515/ijb-2015-0051","DOIUrl":"https://doi.org/10.1515/ijb-2015-0051","url":null,"abstract":"Abstract We present an integer-valued ARCH model which can be used for modeling time series of counts with under-, equi-, or overdispersion. The introduced model has a conditional binomial distribution, and it is shown to be strictly stationary and ergodic. The unknown parameters are estimated by three methods: conditional maximum likelihood, conditional least squares and maximum likelihood type penalty function estimation. The asymptotic distributions of the estimators are derived. A real application of the novel model to epidemic surveillance is briefly discussed. Finally, a generalization of the introduced model is considered by introducing an integer-valued GARCH model.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":"12 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2015-0051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66987783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 24
Testing Equality in Ordinal Data with Repeated Measurements: A Model-Free Approach 用重复测量检验有序数据的相等性:一种无模型方法
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2016-11-01 DOI: 10.1515/ijb-2015-0075
K. Lui
{"title":"Testing Equality in Ordinal Data with Repeated Measurements: A Model-Free Approach","authors":"K. Lui","doi":"10.1515/ijb-2015-0075","DOIUrl":"https://doi.org/10.1515/ijb-2015-0075","url":null,"abstract":"Abstract In randomized clinical trials, we often encounter ordinal categorical responses with repeated measurements. We propose a model-free approach with using the generalized odds ratio (GOR) to measure the relative treatment effect. We develop procedures for testing equality of treatment effects and derive interval estimators for the GOR. We further develop a simple procedure for testing the treatment-by-period interaction. To illustrate the use of test procedures and interval estimators developed here, we consider two real-life data sets, one studying the gender effect on pain scores on an ordinal scale after hip joint resurfacing surgeries, and the other investigating the effect of an active hypnotic drug in insomnia patients on ordinal categories of time to falling asleep.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":"12 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2015-0075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66988065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
A Comparison of Some Approximate Confidence Intervals for a Single Proportion for Clustered Binary Outcome Data 聚类二值结果数据单比例近似置信区间的比较
IF 1.2 4区 数学
International Journal of Biostatistics Pub Date : 2016-11-01 DOI: 10.1515/ijb-2015-0024
Krishna K. Saha, Daniel Miller, Suojin Wang
{"title":"A Comparison of Some Approximate Confidence Intervals for a Single Proportion for Clustered Binary Outcome Data","authors":"Krishna K. Saha, Daniel Miller, Suojin Wang","doi":"10.1515/ijb-2015-0024","DOIUrl":"https://doi.org/10.1515/ijb-2015-0024","url":null,"abstract":"Abstract Interval estimation of the proportion parameter in the analysis of binary outcome data arising in cluster studies is often an important problem in many biomedical applications. In this paper, we propose two approaches based on the profile likelihood and Wilson score. We compare them with two existing methods recommended for complex survey data and some other methods that are simple extensions of well-known methods such as the likelihood, the generalized estimating equation of Zeger and Liang and the ratio estimator approach of Rao and Scott. An extensive simulation study is conducted for a variety of parameter combinations for the purposes of evaluating and comparing the performance of these methods in terms of coverage and expected lengths. Applications to biomedical data are used to illustrate the proposed methods.","PeriodicalId":50333,"journal":{"name":"International Journal of Biostatistics","volume":"37 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/ijb-2015-0024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66987679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
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