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Your search keyword '"Zhong, Yujie"' showing total 17 results
Start Over Author "Zhong, Yujie" Publisher wiley
17 results on '"Zhong, Yujie"'

6. Discovery and validation of extracellular vesicle‐associated miRNAs as noninvasive detection biomarkers for early‐stage non‐small‐cell lung cancer

Author

Zhong, Yujie, primary, Ding, Xiaoyu, additional, Bian, Yuying, additional, Wang, Jing, additional, Zhou, Wanqing, additional, Wang, Xiangdong, additional, Li, Pumin, additional, Shen, Yi, additional, Wang, Jun‐Jun, additional, Li, Jing, additional, Zhang, Chunni, additional, and Wang, Cheng, additional

Published
2021
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16. Selection models for efficient two-phase design of family studies.

Author

Zhong Y and Cook RJ

Subjects
Humans, Research Design
Abstract

Family studies routinely employ biased sampling schemes in which individuals are randomly chosen from a disease registry and genetic and phenotypic data are obtained from their consenting relatives. We view this as a two-phase study and propose the use of an efficient selection model for the recruitment of families to form a phase II sample subject to budgetary constraints. Simple random sampling, balanced sampling and use of an approximately optimal selection model are considered where the latter is chosen to minimize the variance of parameters of interest. We consider the setting where family members provide current status data with respect to the disease and use copula models to address within-family dependence. The efficiency gains from the use of an optimal selection model over simple random sampling and balanced sampling schemes are investigated as is the robustness of optimal sampling to model misspecification. An application to a family study on psoriatic arthritis is given for illustration., (© 2020 John Wiley & Sons Ltd.)

Published
2021
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17. Sample size and robust marginal methods for cluster-randomized trials with censored event times.

Author

Zhong Y and Cook RJ

Subjects
Bias, Child, Child, Preschool, Computer Simulation, Data Interpretation, Statistical, Female, Humans, Infant, Male, Otitis Media drug therapy, Otitis Media surgery, Prednisone therapeutic use, Treatment Failure, Proportional Hazards Models, Randomized Controlled Trials as Topic methods, Sample Size
Abstract

In cluster-randomized trials, intervention effects are often formulated by specifying marginal models, fitting them under a working independence assumption, and using robust variance estimates to address the association in the responses within clusters. We develop sample size criteria within this framework, with analyses based on semiparametric Cox regression models fitted with event times subject to right censoring. At the design stage, copula models are specified to enable derivation of the asymptotic variance of estimators from a marginal Cox regression model and to compute the number of clusters necessary to satisfy power requirements. Simulation studies demonstrate the validity of the sample size formula in finite samples for a range of cluster sizes, censoring rates, and degrees of within-cluster association among event times. The power and relative efficiency implications of copula misspecification is studied, as well as the effect of within-cluster dependence in the censoring times. Sample size criteria and other design issues are also addressed for the setting where the event status is only ascertained at periodic assessments and times are interval censored., (Copyright © 2014 John Wiley & Sons, Ltd.)

Published
2015
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