Modelos inflacionados de zeros: aplicações na análise de um questionário de frequencia alimentar
This study aimed at using zero-inflated models to analyze a food frequency questionnaire (F.F.Q.) applied to elderly individuals from a medium-sized city in inner São P aulo state, investigating the models that can be best fitted to the data according to the percent of zeros found and the factors in...
| Autores: | , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2010 |
| País: | Brasil |
| Recursos: | Universidade Estadual Paulista (UNESP) |
| Repositório: | Repositório Institucional da UNESP |
| Idioma: | português |
| OAI Identifier: | oai:repositorio.unesp.br:11449/140334 |
| Acesso em linha: | http://jaguar.fcav.unesp.br/RME/fasciculos/v28/v28_n1/indice_v28_n1.php http://hdl.handle.net/11449/140334 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Negative binomial distribution Poisson distribution Zero-inflated distribution Food frequency questionnaire Overdispersion Distribuição binomial negativa Distribuição de Poisson |Distribuição inflacionada de zero Questionário de frequência alimentar Superdispersão |
| Resumo: | This study aimed at using zero-inflated models to analyze a food frequency questionnaire (F.F.Q.) applied to elderly individuals from a medium-sized city in inner São P aulo state, investigating the models that can be best fitted to the data according to the percent of zeros found and the factors influencing both intake and non-intake of certain food types. The response variable used was the monthly intake frequency of foods from the F.F.Q., and the associated co-variates were related to socio-demographic characteristics concerning prevention and reported morbidities. The Poisson, Negative Binomial, Zero-Inflated Poisson and Zero-Inflated Negati e Binomial models were used. For a data set with up to 10% of zeros, the usual Negative Binomial model showed to be adequate. Due to data amplitude, the inflated models show ed to b e adequate only at the p ercentage of 1 0 % to 5 0 % of zeros. It was also shown that the probability of consumption of the selected food types was associated with gender, nutritional status, medication use and physical activity practice. The probability of non-consumption was observed in association with gender, bow el functioning and daily water consumption . |
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