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Double Poisson-Tweedie Regression Models.
Petterle, Ricardo R; Bonat, Wagner H; Kokonendji, Célestin C; Seganfredo, Juliane C; Moraes, Atamai; da Silva, Monica G.
Afiliação
  • Petterle RR; Sector of Health Sciences, Medical School, Paraná Federal University, Curitiba, Brazil.
  • Bonat WH; Department of Statistics, Paraná Federal University, Curitiba, Brazil.
  • Kokonendji CC; Laboratoire de Mathématiques de Besançon, Bourgogne Franche-Comté University, Besançon, France.
  • Seganfredo JC; Departamento de Saúde Comunitária, Paraná Federal University, Curitiba, Brazil.
  • Moraes A; Departamento de Saúde Comunitária, Paraná Federal University, Curitiba, Brazil.
  • da Silva MG; Departamento de Saúde Comunitária, Paraná Federal University, Curitiba, Brazil.
Int J Biostat ; 15(1)2019 04 18.
Article em En | MEDLINE | ID: mdl-30998501
In this paper, we further extend the recently proposed Poisson-Tweedie regression models to include a linear predictor for the dispersion as well as for the expectation of the count response variable. The family of the considered models is specified using only second-moments assumptions, where the variance of the count response has the form µ+ϕµp $\mu + \phi \mu^p$, where µ is the expectation, ϕ and p are the dispersion and power parameters, respectively. Parameter estimations are carried out using an estimating function approach obtained by combining the quasi-score and Pearson estimating functions. The performance of the fitting algorithm is investigated through simulation studies. The results showed that our estimating function approach provides consistent estimators for both mean and dispersion parameters. The class of models is motivated by a data set concerning CD4 counting in HIV-positive pregnant women assisted in a public hospital in Curitiba, Paraná, Brazil. Specifically, we investigate the effects of a set of covariates in both expectation and dispersion structures. Our results showed that women living out of the capital Curitiba, with viral load equal or larger than 1000 copies and with previous diagnostic of HIV infection, present lower levels of CD4 cell count. Furthermore, we detected that the time to initiate the antiretroviral therapy decreases the data dispersion. The data set and R code are available as supplementary materials.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Modelos Lineares / Análise de Regressão / Modelos Estatísticos Tipo de estudo: Diagnostic_studies / Prognostic_studies / Risk_factors_studies Limite: Female / Humans / Pregnancy País/Região como assunto: America do sul / Brasil Idioma: En Revista: Int J Biostat Ano de publicação: 2019 Tipo de documento: Article País de afiliação: Brasil País de publicação: Alemanha
Texto completo
Adicionar na Minha BVS
Imprimir
XML
PubMed Links
Buscar no Google

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Modelos Lineares / Análise de Regressão / Modelos Estatísticos Tipo de estudo: Diagnostic_studies / Prognostic_studies / Risk_factors_studies Limite: Female / Humans / Pregnancy País/Região como assunto: America do sul / Brasil Idioma: En Revista: Int J Biostat Ano de publicação: 2019 Tipo de documento: Article País de afiliação: Brasil País de publicação: Alemanha