Chunk #16 — Statistical Methods for Testing and Estimating GxE Interactions — Methods for biological interpretation and for testing specific categories of interaction
A classic test proposed in the context of clinical trials [Gail and Simon 1985], can be easily adapted to test for qualitative GxE interaction in observational studies. The statistical methodology for identification of pure interaction, as defined above, is not well developed and further development of methodologies is merited. One option may be to formulate the problem in terms of a model selection problem, comparing the pure interaction model to a more general model allowing for other types of interactions, using model fit measures such as AIC or BIC or a Bayesian model selection approach.
