Z
Zhongheng Zhang
Researcher at Zhejiang University
Publications - 230
Citations - 9231
Zhongheng Zhang is an academic researcher from Zhejiang University. The author has contributed to research in topics: Intensive care unit & Intensive care. The author has an hindex of 41, co-authored 213 publications receiving 5894 citations. Previous affiliations of Zhongheng Zhang include Sir Run Run Shaw Hospital & Hainan Medical University.
Papers
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Introduction to machine learning: k-nearest neighbors
TL;DR: The article introduces some basic ideas underlying the kNN algorithm, and then focuses on how to perform kNN modeling with R, with a focus on the diagnostic performance of the model.
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Variable selection with stepwise and best subset approaches
TL;DR: Two R functions stepAIC() and bestglm() are well designed for stepwise and best subset regression, respectively.
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Balance diagnostics after propensity score matching
TL;DR: The methods used for assessing balance in covariates after PSM are outlined, which include standardized mean difference (SMD), which is the most commonly used statistic to examine the balance of covariate distribution between treatment groups.
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Multiple imputation with multivariate imputation by chained equation (MICE) package
TL;DR: A step-by-step approach to perform MI by using R multivariate imputation by chained equation (MICE) package and the results obtained from each analysis are combined.
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Time-varying covariates and coefficients in Cox regression models
Zhongheng Zhang,Jaakko Reinikainen,Kazeem Adedayo Adeleke,Marcel E. Pieterse,Catharina G.M. Groothuis-Oudshoorn +4 more
TL;DR: This article aims to illustrate how to carry out statistical analyses in the presence of time-varying covariates or coefficients with R when the proportional hazards assumption of the Cox regression model does not hold.