Data/hora: 11/06/2024 02:08:43

Provedor de dados: | 31
País: | United States
Título: | Sample size calculations for main effects and interactions in case–control studies using Stata's nchi2 and npnchi2 functions
Autores: | Saunders,   Catherine L.; Bishop,   D. Timothy; Barrett,   Jennifer H.
Data: | 2011-09-29
Ano: | 2003
Palavras-chave: | Gene–environment interaction; Gene–gene interaction; Power; Sample size; Study design; Non-central chi^2; Research Methods/ Statistical Methods.
Resumo: | The non-central chi-squared distribution can be used to calculate power for tests detecting departure from a null hypothesis. Required sample size can also be calculated because it is proportional to the non-centrality parameter for the distribution. We demonstrate how these calculations can be carried out in Stata using the example of calculating power and sample size for case–control studies of gene–gene and gene–environment interactions. Do-files are available for these calculations.
Tipo: | Journal Article
Idioma: | Inglês

Identificador:

st0032

http://purl.umn.edu/116031

Relação: | Stata Journal&gt;Volume 3, Number 1, 1st Quarter 2003
Formato: | 10