tlmec swMATH ID: 11119 Software Authors: Matos, Larissa A.; Prates, Marcos O.; Chen, Ming-Hui; Lachos, Victor H. Description: Likelihood-based inference for mixed-effects models with censored response using the multivariate-t distribution. Mixed-effects models are commonly used to fit longitudinal or repeated measures data. A complication arises when the response is censored, for example, due to limits of quantification of the assay used. Although normal distributions are commonly assumed for random effects and residual errors, such assumptions make inferences vulnerable to outliers. The sensitivity to outliers and the need for heavy tailed distributions for random effects and residual errors motivate us to develop a likelihood-based inference for linear and nonlinear mixed effects models with censored response (NLMEC/LMEC) based on the multivariate Student-t distribution. An ECM algorithm is developed for computing the maximum likelihood estimates for NLMEC/LMEC with the standard errors of the fixed effects and the exact likelihood value as a by-product. The algorithm uses closed-form expressions at the E-step, that rely on formulas for the mean and variance of a truncated multivariate-t distribution. The proposed algorithm is implemented in the R package tlmec. It is applied to analyze longitudinal HIV viral load data in two recent AIDS studies. In addition, a simulation study is conducted to examine the performance of the proposed method and to compare it with the approach of Vaida and Liu (2009). Homepage: http://cran.r-project.org/web/packages/tlmec/index.html Source Code: https://github.com/cran/tlmec Dependencies: R Keywords: censored data; ECM algorithm; HIV viral load; influential observations; mixed-effects models; outliers Related Software: R; lmec; mvtnorm; MomTrunc; CensMixReg; sn; MEMSS; S-PLUS; SASmixed; NLopt; nloptr; SAS; NEWUOA; Mathematica; CensMFM; tlrmvnmvt; bootstrap; QSIMVN; AS 136; mclust Cited in: 19 Publications Standard Articles 1 Publication describing the Software, including 1 Publication in zbMATH Year Likelihood-based inference for mixed-effects models with censored response using the multivariate-\(t\) distribution. Zbl 06202709Matos, Larissa A.; Prates, Marcos O.; Chen, Ming-Hui; Lachos, Victor H. 2013 all top 5 Cited by 32 Authors 13 Lachos Dávila, Víctor Hugo 5 Matos, Larissa A. 5 Prates, Marcos Oliveira 4 Dey, Dipak Kumar 3 Cabral, Celso Rômulo Barbosa 3 Castro, Luis Mauricio 3 Costa, Denise Reis 2 Galarza, Christian E. 2 Lin, Tsung I. 2 Tian, Maozai 2 Tian, Yuzhu 2 Wang, Wan-Lun 1 Arellano-Valle, Reinaldo Boris 1 Azevedo, Caio Lucidius Naberezny 1 Bazán, Jorge Luis 1 Brini, Alberto 1 Chen, Kun 1 Chen, Minghui 1 Haakma, Reinder 1 Li, Erqian 1 Loschi, Rosangela Helena 1 Morales, Christian E. Galarza 1 Moreno, Edgar J. López 1 Nooraee, Nazanin 1 Regis, Marta 1 Rocha, Gustavo H. M. A. 1 Schumacher, Fernanda L. 1 Tang, Manlai 1 van den Heuvel, Edwin R. 1 Wang, Liyong 1 Yang, Fengkai 1 Yuan, Haijing all top 5 Cited in 13 Serials 3 Test 2 Journal of Multivariate Analysis 2 Computational Statistics 2 Communications in Statistics. Simulation and Computation 2 Statistics and Computing 1 Metrika 1 Metron 1 Statistics 1 Journal of Statistical Computation and Simulation 1 Computational Statistics and Data Analysis 1 Statistica Sinica 1 Journal of Statistical Theory and Practice 1 Journal of Computational and Graphical Statistics Cited in 3 Fields 19 Statistics (62-XX) 1 Numerical analysis (65-XX) 1 Biology and other natural sciences (92-XX) Citations by Year