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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Box-Cox t random intercept model for estimating usual nutrient intake distributions

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Fumes-Ghantous, Giovana [1] ; Ferrari, Silvia L. P. [2] ; Corrente, Jose Eduardo [3]
Total Authors: 3
[1] Univ Sao Paulo, FZEA, Dept Basic Sci, Pirassununga - Brazil
[2] Univ Sao Paulo, Dept Stat, Sao Paulo - Brazil
[3] Univ Sao Paulo State, Dept Biostat, Botucatu, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Statistical Methods and Applications; v. 27, n. 4, p. 715-734, DEC 2018.
Web of Science Citations: 0

The issue of estimating usual nutrient intake distributions and prevalence of inadequate nutrient intakes is of interest in nutrition studies. Box-Cox transformations coupled with the normal distribution are usually employed for modeling nutrient intake data. When the data present highly asymmetric distribution or include outliers, this approach may lead to implausible estimates. Additionally, it does not allow interpretation of the parameters in terms of characteristics of the original data and requires back transformation of the transformed data to the original scale. This paper proposes an alternative approach for estimating usual nutrient intake distributions and prevalence of inadequate nutrient intakes through a Box-Cox t model with random intercept. The proposed model is flexible enough for modeling highly asymmetric data even when outliers are present. Unlike the usual approach, the proposed model does not require a transformation of the data. A simulation study suggests that the Box-Cox t model with random intercept estimates the usual intake distribution satisfactorily, and that it should be preferable to the usual approach particularly in cases of highly asymmetric heavy-tailed data. In applications to data sets on intake of 19 micronutrients, the Box-Cox t models provided better fit than its competitors in most of the cases. (AU)

FAPESP's process: 08/10261-8 - Evaluation of the nutritional adequacy for elderly people
Grantee:José Eduardo Corrente
Support type: Regular Research Grants
FAPESP's process: 12/21788-2 - Regression models and applications
Grantee:Heleno Bolfarine
Support type: Research Projects - Thematic Grants