Question
You are using a chi squared test of homogeneity to assess whether an infant’s HIV status is an effect measure modifier of the relationship between food insecurity and diarrheal illness. You stratify your data and calculate a chi squared test of homogeneity using your stratum-specific estimates. If your p-value is lower than your established significance level, based on this evidence is HIV status an effect measure modifier of the relationship between food insecurity and diarrheal illness? Justify your answer.
