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1. A hybrid omnibus test for generalized semiparametric single‐index models with high‐dimensional covariate sets

Author:
Carroll, Raymond J.,   et al.   ; Xu, Yangyi; Kim, Inyoung;     Show all 3 Authors
Source:
Biometrics 2019 v.75 no.3 pp. 757-767
ISSN:
0006-341X
Subject:
Bayesian theory; biometry; equations; models; noninsulin-dependent diabetes mellitus; probability; statistical analysis
Abstract:
... Numerous statistical methods have been developed for analyzing high‐dimensional data. These methods often focus on variable selection approaches but are limited for the purpose of testing with high‐dimensional data. They are often required to have explicit‐likelihood functions. In this article, we propose a “hybrid omnibus test” for high‐dicmensional data testing purpose with much weaker requireme ...
DOI:
10.1111/biom.13054
PubMed:
30859553
PubMed Central:
PMC6736718

2. MALMEM: model averaging in linear measurement error models

Author:
Carroll, Raymond J.,   et al.   ; Zhang, Xinyu; Ma, Yanyuan;     Show all 3 Authors
Source:
Journal of the Royal Statistical Society 2019 v.81 no.4 pp. 763-779
ISSN:
1369-7412
Subject:
Bayesian theory; equations; models; regression analysis
Abstract:
... We develop model averaging estimation in the linear regression model where some covariates are subject to measurement error. The absence of the true covariates in this framework makes the calculation of the standard residual‐based loss function impossible. We take advantage of the explicit form of the parameter estimators and construct a weight choice criterion. It is asymptotically equivalent to ...
DOI:
10.1111/rssb.12317

3. Modeling and Prediction of Multiple Correlated Functional Outcomes

Author:
Carroll, Raymond J.,   et al.   ; Cao, Jiguo; Soiaporn, Kunlaya; Ruppert, David;     Show all 4 Authors
Source:
Journal of agricultural, biological, and environmental statistics 2019 v.24 no.1 pp. 112-129
ISSN:
1085-7117
Subject:
algorithms; image analysis; models; patients; prediction; sclerosis
Abstract:
... We propose a copula-based approach for analyzing functional data with correlated multiple functional outcomes exhibiting heterogeneous shape characteristics. To accommodate the possibly large number of parameters due to having several functional outcomes, parameter estimation is performed in two steps: first, the parameters for the marginal distributions are estimated using the skew t family, and ...
DOI:
10.1007/s13253-018-00344-0
PubMed:
30956522
PubMed Central:
PMC6447061

4. Semiparametrically efficient estimation in quantile regression of secondary analysis

Author:
Carroll, Raymond J.,   et al.   ; Liang, Liang; Ma, Yanyuan; Wei, Ying;     Show all 4 Authors
Source:
Journal of the Royal Statistical Society 2018 v.80 no.4 pp. 625-648
ISSN:
1369-7412
Subject:
case-control studies; complement; equations; models; regression analysis; risk
Abstract:
... Analysing secondary outcomes is a common practice for case–control studies. Traditional secondary analysis employs either completely parametric models or conditional mean regression models to link the secondary outcome to covariates. In many situations, quantile regression models complement mean‐based analyses and provide alternative new insights on the associations of interest. For example, biome ...
DOI:
10.1111/rssb.12272
PubMed:
30337833
PubMed Central:
PMC6191046

5. Testing for gene–environment interaction under exposure misspecification

Author:
Carroll, Raymond J.,   et al.   ; Sun, Ryan; Christiani, David C.; Lin, Xihong;     Show all 4 Authors
Source:
Biometrics 2018 v.74 no.2 pp. 653-662
ISSN:
0006-341X
Subject:
biometry; environmental exposure; environmental factors; etiology; genetic factors; genotype-environment interaction; models; regression analysis; variance
Abstract:
... Complex interplay between genetic and environmental factors characterizes the etiology of many diseases. Modeling gene–environment (GxE) interactions is often challenged by the unknown functional form of the environment term in the true data‐generating mechanism. We study the impact of misspecification of the environmental exposure effect on inference for the GxE interaction term in linear and log ...
DOI:
10.1111/biom.12813
PubMed:
29120492
PubMed Central:
PMC5943197

6. Measurement error correction and sensitivity analysis in longitudinal dietary intervention studies using an external validation study

Author:
Carroll, Raymond J.,   et al.   ; Siddique, Juned; Daniels, Michael J.; Raghunathan, Trivellore E.; Stuart, Elizabeth A.; Freedman, Laurence S.;     Show all 6 Authors
Source:
Biometrics 2019 v.75 no.3 pp. 927-937
ISSN:
0006-341X
Subject:
biomarkers; biometry; eating habits; food intake; lifestyle; nutritional intervention; sodium
Abstract:
... In lifestyle intervention trials, where the goal is to change a participant's weight or modify their eating behavior, self‐reported diet is a longitudinal outcome variable that is subject to measurement error. We propose a statistical framework for correcting for measurement error in longitudinal self‐reported dietary data by combining intervention data with auxiliary data from an external biomark ...
DOI:
10.1111/biom.13044

7. Estimating varying coefficients for partial differential equation models

Author:
Carroll, Raymond J.,   et al.   ; Zhang, Xinyu; Cao, Jiguo;     Show all 3 Authors
Source:
Biometrics 2017 v.73 no.3 pp. 949-959
ISSN:
0006-341X
Subject:
biometry; equations; lidar; models
Abstract:
... Partial differential equations (PDEs) are used to model complex dynamical systems in multiple dimensions, and their parameters often have important scientific interpretations. In some applications, PDE parameters are not constant but can change depending on the values of covariates, a feature that we call varying coefficients. We propose a parameter cascading method to estimate varying coefficient ...
DOI:
10.1111/biom.12646
PubMed:
28076654
PubMed Central:
PMC5505821

8. Semiparametric estimation in the secondary analysis of case–control studies

Author:
Carroll, Raymond J.,   et al.   ; Ma, Yanyuan;     Show all 2 Author
Source:
Journal of the Royal Statistical Society 2016 v.78 no.1 pp. 127-151
ISSN:
1369-7412
Subject:
amines; case-control studies; colorectal neoplasms; computer software; heteroskedasticity; meat consumption; models; red meat; risk factors; variance
Abstract:
... We study the regression relationship between covariates in case–control data: an area known as the secondary analysis of case–control studies. The context is such that only the form of the regression mean is specified, so that we allow an arbitrary regression error distribution, which can depend on the covariates and thus can be heteroscedastic. Under mild regularity conditions we establish the th ...
DOI:
10.1111/rssb.12107
PubMed:
26834506
PubMed Central:
PMC4731052

9. A Powerful Bayesian Test for Equality of Means in High Dimensions

Author:
Carroll, Raymond J.,   et al.   ; Zoh, Roger S.; Sarkar, Abhra; Mallick, Bani K.;     Show all 4 Authors
Source:
Journal of the American Statistical Association 2018 v.113 no.524 pp. 1733-1741
ISSN:
1537-274X
Subject:
Bayesian theory; equations; models; variance covariance matrix
Abstract:
... We develop a Bayes factor-based testing procedure for comparing two population means in high-dimensional settings. In ‘large-p-small-n” settings, Bayes factors based on proper priors require eliciting a large and complex p × p covariance matrix, whereas Bayes factors based on Jeffrey’s prior suffer the same impediment as the classical Hotelling T² test statistic as they involve inversion of ill-fo ...
DOI:
10.1080/01621459.2017.1371024
PubMed:
30739967
PubMed Central:
PMC6364997

10. Functional multiple indicators, multiple causes measurement error models

Author:
Carroll, Raymond J.,   et al.   ; Tekwe, Carmen D.; Zoh, Roger S.; Bazer, Fuller W.; Wu, Guoyao;     Show all 5 Authors
Source:
Biometrics 2018 v.74 no.1 pp. 127-134
ISSN:
0006-341X
Subject:
algorithms; biometry; carbon dioxide production; data collection; energy expenditure; heat production; metabolism; models; oxygen consumption; rats; respiratory quotient; variance
Abstract:
... Objective measures of oxygen consumption and carbon dioxide production by mammals are used to predict their energy expenditure. Since energy expenditure is not directly observable, it can be viewed as a latent construct with multiple physical indirect measures such as respiratory quotient, volumetric oxygen consumption, and volumetric carbon dioxide production. Metabolic rate is defined as the rat ...
DOI:
10.1111/biom.12706
PubMed:
28482110
PubMed Central:
PMC5677589

11. Bayesian Semiparametric Multivariate Density Deconvolution

Author:
Carroll, Raymond J.,   et al.   ; Sarkar, Abhra; Pati, Debdeep; Chakraborty, Antik; Mallick, Bani K.;     Show all 5 Authors
Source:
Journal of the American Statistical Association 2018 v.113 no.521 pp. 401-416
ISSN:
1537-274X
Subject:
Bayesian theory; food consumption; food contamination; mathematical theory; models; multivariate analysis
Abstract:
... We consider the problem of multivariate density deconvolution when interest lies in estimating the distribution of a vector valued random variable X but precise measurements on X are not available, observations being contaminated by measurement errors U. The existing sparse literature on the problem assumes the density of the measurement errors to be completely known. We propose robust Bayesian se ...
DOI:
10.1080/01621459.2016.1260467
PubMed:
30078920
PubMed Central:
PMC6075844

12. Linear Model Selection When Covariates Contain Errors

Author:
Carroll, Raymond J.,   et al.   ; Zhang, Xinyu; Wang, Haiying; Ma, Yanyuan;     Show all 4 Authors
Source:
Journal of the American Statistical Association 2017 v.112 no.520 pp. 1553-1561
ISSN:
1537-274X
Subject:
data collection; linear models; model validation; prediction; regression analysis
Abstract:
... Prediction precision is arguably the most relevant criterion of a model in practice and is often a sought after property. A common difficulty with covariates measured with errors is the impossibility of performing prediction evaluation on the data even if a model is completely given without any unknown parameters. We bypass this inherent difficulty by using special properties on moment relations i ...
DOI:
10.1080/01621459.2016.1219262
PubMed:
29416191
PubMed Central:
PMC5798903

13. Best Practices for Dietary Supplement Assessment and Estimation of Total Usual Nutrient Intakes in Population-Level Research and Monitoring

Author:
Carroll, Raymond J,   et al.   ; Bailey, Regan L; Dodd, Kevin W; Gahche, Jaime J; Dwyer, Johanna T; Cowan, Alexandra E; Jun, Shinyoung; Eicher-Miller, Heather A; Guenther, Patricia M; Bhadra, Anindya; Thomas, Paul R; Potischman, Nancy; Tooze, Janet A;     Show all 13 Authors
Source:
TheJournal of nutrition 2019 v.149 no.2 pp. 181-197
ISSN:
1541-6100
Subject:
bioavailability; dietary supplements; energy intake; food intake; food matrix; foods; issues and policy; monitoring; nutrients; nutrition research
Abstract:
... The use of dietary supplements (DS) is pervasive and can provide substantial amounts of micronutrients to those who use them. Therefore when characterizing dietary intakes, describing the prevalence of inadequacy or excess, or assessing relations between nutrients and health outcomes, it is critical to incorporate DS intakes to improve exposure estimates. Unfortunately, little is known about the b ...
DOI:
10.1093/jn/nxy264
PubMed:
30753685
PubMed Central:
PMC6374152

14. The direct integral method for confidence intervals for the ratio of two location parameters

Author:
Carroll, Raymond J.,   et al.   ; Wang, Yanqing; Wang, Suojin;     Show all 3 Authors
Source:
Biometrics 2015 v.71 no.3 pp. 704-713
ISSN:
0006-341X
Subject:
biometry; confidence interval; data collection; men; nutrition; relative risk; risk analysis; women
Abstract:
... In a relative risk analysis of colorectal caner on nutrition intake scores across genders, we show that, surprisingly, when comparing the relative risks for men and women based on the index of a weighted sum of various nutrition scores, the problem reduces to forming a confidence interval for the ratio of two (asymptotically) normal random variables. The latter is an old problem, with a substantia ...
DOI:
10.1111/biom.12318
PubMed:
25939421
PubMed Central:
PMC4575252

15. On the selection of ordinary differential equation models with application to predator‐prey dynamical models

Author:
Carroll, Raymond J.,   et al.   ; Zhang, Xinyu; Cao, Jiguo;     Show all 3 Authors
Source:
Biometrics 2015 v.71 no.1 pp. 131-138
ISSN:
0006-341X
Subject:
Lynx; Monte Carlo method; biometry; confidence interval; dynamic models; equations; hares; least squares; predator-prey relationships
Abstract:
... We consider model selection and estimation in a context where there are competing ordinary differential equation (ODE) models, and all the models are special cases of a “full” model. We propose a computationally inexpensive approach that employs statistical estimation of the full model, followed by a combination of a least squares approximation (LSA) and the adaptive Lasso. We show the resulting m ...
DOI:
10.1111/biom.12243

16. Variance function partially linear single‐index models

Author:
Carroll, Raymond J.,   et al.   ; Lian, Heng; Liang, Hua;     Show all 3 Authors
Source:
Journal of the Royal Statistical Society 2015 v.77 no.1 pp. 171-194
ISSN:
1369-7412
Subject:
heteroskedasticity; models; ozone; regression analysis; variance
Abstract:
... We consider heteroscedastic regression models where the mean function is a partially linear single‐index model and the variance function depends on a generalized partially linear single‐index model. We do not insist that the variance function depends only on the mean function, as happens in the classical generalized partially linear single‐index model. We develop efficient and practical estimation ...
DOI:
10.1111/rssb.12066
PubMed:
25642139
PubMed Central:
PMC4310508

17. A bivariate measurement error model for semicontinuous and continuous variables: Application to nutritional epidemiology

Author:
Carroll, Raymond J.,   et al.   ; Kipnis, Victor; Freedman, Laurence S.; Midthune, Douglas;     Show all 4 Authors
Source:
Biometrics 2016 v.72 no.1 pp. 106-115
ISSN:
0006-341X
Subject:
biometry; energy intake; epidemiology; food frequency questionnaires; food intake; models; risk
Abstract:
... Semicontinuous data in the form of a mixture of a large portion of zero values and continuously distributed positive values frequently arise in many areas of biostatistics. This article is motivated by the analysis of relationships between disease outcomes and intakes of episodically consumed dietary components. An important aspect of studies in nutritional epidemiology is that true diet is unobse ...
DOI:
10.1111/biom.12377
PubMed:
26332011
PubMed Central:
PMC4775438

18. Constrained Maximum Likelihood Estimation for Model Calibration Using Summary-Level Information From External Big Data Sources

Author:
Carroll, Raymond J.,   et al.   ; Chatterjee, Nilanjan; Chen, Yi-Hau; Maas, Paige;     Show all 4 Authors
Source:
Journal of the American Statistical Association 2016 v.111 no.513 pp. 107-117
ISSN:
1537-274X
Subject:
equations; mathematical theory; models; regression analysis; surveys; variance
Abstract:
... Information from various public and private data sources of extremely large sample sizes are now increasingly available for research purposes. Statistical methods are needed for using information from such big data sources while analyzing data from individual studies that may collect more detailed information required for addressing specific hypotheses of interest. In this article, we consider the ...
DOI:
10.1080/01621459.2015.1123157
PubMed:
27570323
PubMed Central:
PMC4994914

19. A Semiparametric Single-Index Risk Score Across Populations

Author:
Carroll, Raymond J.,   et al.   ; Ma, Shujie; Ma, Yanyuan; Wang, Yanqing; Kravitz, Eli S.;     Show all 5 Authors
Source:
Journal of the American Statistical Association 2017 v.112 no.520 pp. 1648-1662
ISSN:
1537-274X
Subject:
epidemiology; health effects assessments; knots; mathematical theory; milk consumption; risk; simulation models; statistical models
Abstract:
... We consider a problem motivated by issues in nutritional epidemiology, across diseases and populations. In this area, it is becoming increasingly common for diseases to be modeled by a single diet score, such as the Healthy Eating Index, the Mediterranean Diet Score, etc. For each disease and for each population, a partially linear single-index model is fit. The partially linear aspect of the prob ...
DOI:
10.1080/01621459.2016.1222944
PubMed:
29520120
PubMed Central:
PMC5839692

20. PLEMT: A Novel Pseudolikelihood-Based EM Test for Homogeneity in Generalized Exponential Tilt Mixture Models

Author:
Carroll, Raymond J.,   et al.   ; Hong, Chuan; Ning, Yang; Wang, Shuang; Wu, Hao; Chen, Yong;     Show all 6 Authors
Source:
Journal of the American Statistical Association 2017 v.112 no.520 pp. 1393-1404
ISSN:
1537-274X
Subject:
DNA methylation; data collection; epigenetics; ovarian neoplasms; statistical models; variance
Abstract:
... Motivated by analyses of DNA methylation data, we propose a semiparametric mixture model, namely, the generalized exponential tilt mixture model, to account for heterogeneity between differentially methylated and nondifferentially methylated subjects in the cancer group, and capture the differences in higher order moments (e.g., mean and variance) between subjects in cancer and normal groups. A pa ...
DOI:
10.1080/01621459.2017.1280405
PubMed:
29416190
PubMed Central:
PMC5798902