18 citations · 89 across the 13 of their papers we have counts for
13 papers
Variance for Estimation and Prediction in Linear Mixed Effects Models Under MAR
Yongqiang Tang
In linear mixed effects models (LMM), inference on fixed effects typically relies on either the generalized least squares (GLS) variance estimator obtained by assuming that the var…
Monotone data augmentation algorithm for longitudinal continuous, binary and ordinal outcomes: a unifying approach
Yongqiang Tang
The monotone data augmentation (MDA) algorithm has been widely used to impute missing data for longitudinal continuous outcomes. Compared to a full data augmentation approach, the…
MOVER confidence intervals for a difference or ratio effect parameter under stratified sampling
Yongqiang Tang
Stratification is commonly employed in clinical trials to reduce the chance covariate imbalances and increase the precision of the treatment effect estimate. We propose a general f…
Sample size calculation for the Andersen-Gill model comparing rates of recurrent events
Yongqiang Tang, Ronan Fitzpatrick
Recurrent events arise frequently in biomedical research, where the subject may experience the same type of events more than once. The Andersen-Gill (AG) model has become increasin…
An improved sample size calculation method for score tests in generalized linear models
Yongqiang Tang, Liang Zhu, Jiezhun Gu
Self and Mauritsen (1988) developed a sample size determination procedure for score tests in generalized linear models under contiguous alternatives. Its performance may deteriorat…
Notes on Exact Power Calculations for t Tests and Analysis of Covariance
Yongqiang Tang
Tang derived the exact power formulae for t tests and analysis of covariance (ANCOVA) in superiority, noninferiority and equivalence trials. The power calculation in equivalence tr…
A monotone data augmentation algorithm for longitudinal data analysis via multivariate skew-t, skew-normal or t distributions
Yongqiang Tang
The mixed effects model for repeated measures (MMRM) has been widely used for the analysis of longitudinal clinical data collected at a number of fixed time points. We propose a ro…
A monotone data augmentation algorithm for multivariate nonnormal data: with applications to controlled imputations for longitudinal trials
Yongqiang Tang
An efficient monotone data augmentation (MDA) algorithm is proposed for missing data imputation for incomplete multivariate nonnormal data that may contain variables of different t…
A noniterative sample size procedure for tests based on t distributions
Yongqiang Tang
A noniterative sample size procedure is proposed for a general hypothesis test based on the t distribution by modifying and extending Guenther's (1981) approach for the one sample…
Sample size for comparing negative binomial rates in noninferiority and equivalence trials with unequal follow-up times
Yongqiang Tang
We derive the sample size formulae for comparing two negative binomial rates based on both the relative and absolute rate difference metrics in noninferiority and equivalence trial…
Closed-form REML estimators and sample size determination for mixed effects models for repeated measures under monotone missingness
Yongqiang Tang
We derive the closed-form restricted maximum likelihood (REML) estimator and Kenward-Roger's variance estimator for fixed effects in the mixed effects model for repeated measures (…
An efficient multiple imputation algorithm for control-based and delta-adjusted pattern mixture models using SAS
Yongqiang Tang
In clinical trials, mixed effects models for repeated measures (MMRM) and pattern mixture models (PMM) are often used to analyze longitudinal continuous outcomes. We describe a sim…
Posterior consistency of Dirichlet mixtures of beta densities in estimating positive false discovery rates
Subhashis Ghosal, Anindya Roy, Yongqiang Tang
In recent years, multiple hypothesis testing has come to the forefront of statistical research, ostensibly in relation to applications in genomics and some other emerging fields. T…