# Logistic regression and odds ratio

If the odds ratio is greater than one with an insignificant p value for a variable in logistic regression should the variable be kept in the model?

Can I select the variable with odds close to 1?

Question 2: In the validation and testing dataset do not have same mean how to handle it?

• Please post these questions separately. – russellpierce Jan 27 '13 at 10:39
• See here. – Scortchi Jan 28 '13 at 8:57

What does not have the same mean? If you are using binary logistic regression and are referring to the prevalence of $Y$, this can vary from sample to sample as long as what explains the difference is captured in the covariates. But the bigger problem is that data splitting is a highly inefficient way to validate a logistic model. My course notes present better ways: http://biostat.mc.vanderbilt.edu/rms .