I am doing logistic regression to assess the influence of a novel parameter on the risk for a certain disease and I have 2 questions:
(1) Is it appropriate to logarithmize one or more independent variables in logistic regression analysis? I want to describe odds ratios per per 1-SD increase, and, as parameter I am investigating is not normally distributed, this would make a 1-SD increase more concrete. Also, the odds ratios look much better if I use the logarithmized parameter an independent variable and then calculate SD-scores, rather than calculating SD scores of the untransformed variable.
(2) How can I describe my reasons for log-transforming the marker in my METHODS section on my paper? Should I simply put that I want to make a one SD increase more concrete?
Much thanks in advance for any answer! Martin