| Full text | |
| Author(s): |
Total Authors: 4
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| Affiliation: | [1] Univ Estadual Campinas, Dept Stat, Campinas, SP - Brazil
[2] Univ Connecticut, Dept Stat, Storrs, CT 06269 - USA
[3] Natl Chung Hsing Univ, Inst Stat, Taichung 402 - Taiwan
[4] China Med Univ, Dept Publ Hlth, Taichung 404 - Taiwan
[5] Pontificia Univ Catolica Chile, Dept Stat, Santiago - Chile
Total Affiliations: 5
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| Document type: | Journal article |
| Source: | TEST; v. 28, n. 3, p. 844-878, SEP 2019. |
| Web of Science Citations: | 0 |
| Abstract | |
Longitudinal HIV-1 RNA viral load measures are often subject to censoring due to upper and lower detection limits depending on the quantification assays. A complication arises when these continuous measures present a heavy-tailed behavior because inference can be seriously affected by the misspecification of their parametric distribution. For such data structures, we propose a robust nonlinear censored regression model based on the scale mixtures of normal distributions. By taking into account the autocorrelation existing among irregularly observed measures, a damped exponential correlation structure is considered. A stochastic approximation of the EM algorithm is developed to obtain the maximum likelihood estimates of the model parameters. The main advantage of this new procedure os to allow estimating the parameters of interest and evaluating the log-likelihood function easily and quickly. Furthermore, the standard errors of the fixed effects and predictions of unobservable values of the response can be obtained as a byproduct. The practical utility of the proposed method is exemplified using both simulated and real data. (AU) | |
| FAPESP's process: | 15/05385-3 - Estimation in mixed-effects models with censored response using scale mixtures of normal distributions |
| Grantee: | Larissa Avila Matos |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |
| FAPESP's process: | 18/05013-7 - Semiparametric mixed effects models with multiple censored response using scale mixtures of normal distributions |
| Grantee: | Larissa Avila Matos |
| Support Opportunities: | Research Grants - Visiting Researcher Grant - International |
| FAPESP's process: | 14/02938-9 - Estimation and diagnostics for censored mixed effects models using scale mixtures of skew-normal distributions |
| Grantee: | Víctor Hugo Lachos Dávila |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 11/22063-9 - APPLICATIONS OF THE SCALE MIXTURES OF SKEW-NORMAL DISTRIBUTIONS IN FACTOR ANALYSIS MODELS |
| Grantee: | Larissa Avila Matos |
| Support Opportunities: | Scholarships in Brazil - Doctorate |