Testing departure from additivity in Tukey's model using shrinkage: application to a longitudinal setting.

ABSTRACT: While there has been extensive research developing gene-environment interaction (GEI) methods in case-control studies, little attention has been given to sparse and efficient modeling of GEI in longitudinal studies. In a two-way table for GEI with rows and columns as categorical variables, a conventional saturated interaction model involves estimation of a specific parameter for each cell, with constraints ensuring identifiability. The estimates are unbiased but are potentially inefficient because the number of parameters to be estimated can grow quickly with increasing categories of row/column factors. On the other hand, Tukey's one-degree-of-freedom model for non-additivity treats the interaction term as a scaled product of row and column main effects. Because of the parsimonious form of

SUBMITTER: Ko YA 

PROVIDER: S-EPMC4227925 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature