Multivariate longitudinal data analysis with censored and intermittent missing responses

• Published in: Statistics in medicine Vol. 37; no. 19; pp. 2822 - 2835
• Main Authors: Lin, Tsung‐I, Lachos, Victor H., Wang, Wan‐Lun
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 30.08.2018
• Subjects: censored data; ECM algorithm; Economic models; HIV AIDS study; Missing data; missing‐data imputation; Normal distribution; truncated multivariate normal distribution; missing-data imputation; ECM algorithm; censored data; truncated multivariate normal distribution; HIV AIDS study
• ISSN: 0277-6715; 1097-0258; 1097-0258
• DOI: 10.1002/sim.7692

The multivariate linear mixed model (MLMM) has emerged as an important analytical tool for longitudinal data with multiple outcomes. However, the analysis of multivariate longitudinal data could be complicated by the presence of censored measurements because of a detection limit of the assay in combination with unavoidable missing values arising when subjects miss some of their scheduled visits intermittently. This paper presents a generalization of the MLMM approach, called the MLMM‐CM, for a joint analysis of the multivariate longitudinal data with censored and intermittent missing responses. A computationally feasible expectation maximization–based procedure is developed to carry out maximum likelihood estimation within the MLMM‐CM framework. Moreover, the asymptotic standard errors of fixed effects are explicitly obtained via the information‐based method. We illustrate our methodology by using simulated data and a case study from an AIDS clinical trial. Experimental results reveal that the proposed method is able to provide more satisfactory performance as compared with the traditional MLMM approach.