Zsuzsanna Papp
2011-Nov-29 03:45 UTC
[R] How to calculate confidence interval for each level of a binary explanatory variable when there is interaction
I have a logistic regression model with several categorical explanatory variables and one interaction term (between two binary variables, named A and B). I know how to calculate the odds ratios for the different levels of A and B (for A=1, e.g., I need to add the coeff for A to coeff for A*B, then exponentiate), but how do I get a confidence interval for this OR? I can get the confidence interval using "confint" for A (when A=0), and B (when B=0) and A*B, but I would like to get the confidence interval for the OR of level 1 of A and for level 1 of B. Thank you for any advice or question asking for clarification.