@article {yi_simultaneous_2011, title = {Simultaneous Inference and Bias Analysis for Longitudinal Data with Covariate Measurement Error and Missing Responses}, journal = {Biometrics}, volume = {67}, number = {1}, year = {2011}, month = {mar}, pages = {67{\textendash}75}, abstract = {Summary Longitudinal data arise frequently in medical studies and it is common practice to analyze such data with generalized linear mixed models. Such models enable us to account for various types of heterogeneity, including between- and within-subjects ones. Inferential procedures complicate dramatically when missing observations or measurement error arise. In the literature, there has been considerable interest in accommodating either incompleteness or covariate measurement error under random effects models. However, there is relatively little work concerning both features simultaneously. There is a need to fill up this gap as longitudinal data do often have both characteristics. In this article, our objectives are to study simultaneous impact of missingness and covariate measurement error on inferential procedures and to develop a valid method that is both computationally feasible and theoretically valid. Simulation studies are conducted to assess the performance of the proposed method, and a real example is analyzed with the proposed method.}, keywords = {Bias analysis, Longitudinal data, Measurement error, missing data, Monte Carlo EM algorithm, Random effects models}, issn = {1541-0420}, doi = {10.1111/j.1541-0420.2010.01437.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1541-0420.2010.01437.x/abstract}, author = {Yi, G. Y. and Liu, W. and WU, LANG} } @article {liu_simultaneous_2007, title = {Simultaneous Inference for Semiparametric Nonlinear Mixed-Effects Models with Covariate Measurement Errors and Missing Responses}, journal = {Biometrics}, volume = {63}, number = {2}, year = {2007}, month = {jun}, pages = {342{\textendash}350}, abstract = {Summary Semiparametric nonlinear mixed-effects (NLME) models are flexible for modeling complex longitudinal data. Covariates are usually introduced in the models to partially explain interindividual variations. Some covariates, however, may be measured with substantial errors. Moreover, the responses may be missing and the missingness may be nonignorable. We propose two approximate likelihood methods for semiparametric NLME models with covariate measurement errors and nonignorable missing responses. The methods are illustrated in a real data example. Simulation results show that both methods perform well and are much better than the commonly used naive method.}, keywords = {Cubic spline basis, Longitudinal data, Monte Carlo EM algorithm, Random-effects model}, issn = {1541-0420}, doi = {10.1111/j.1541-0420.2006.00687.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1541-0420.2006.00687.x/abstract}, author = {Liu, Wei and WU, LANG} }