I'm looking at the association between one binary dependent variable, and several independent variables. I first did univariate analysis, and then put all variables with p<0.05 into a logistic regression model.
My issue is this: a couple of the variables produced odds ratios <1 on regression analysis, despite univariate analysis demonstrating positive associations between the dependent variable and the independent variables in question (i.e. I would have expected OR>1).
Can this be explained by taking into account the confounding effect of other variables? Or does it mean I have done something wrong?
Thanks
My issue is this: a couple of the variables produced odds ratios <1 on regression analysis, despite univariate analysis demonstrating positive associations between the dependent variable and the independent variables in question (i.e. I would have expected OR>1).
Can this be explained by taking into account the confounding effect of other variables? Or does it mean I have done something wrong?
Thanks