Re: st: Stepwise logistic regression with categorical variables

[Thomas Trikalinos (.Mac) <ttrikalin@mac.com>]

try entering eg i.v25 in parentheses. This means that all the v25 dummies are considered together as a group:

xi: sw logistic status v3 i.v5 v6 v17 v18 v19 v21 (i.v25) v26 i.v27 i.v28 i.v29 i.v30 i.v31
Cheers

Tom

On Jun 7, 2004, at 17:37, Rachel Wade wrote:

Hello,

�

I am trying to carry out a stepwise logistic regression (I am aware of its limitations and am using it for exploratory purposes) and have a combination of categorical and continuous variables I wish to potentially include in a model.�

For example the line of code below:

xi: sw logistic status v3 i.v5 v6 v17 v18 v19 v21 i.v25 v26 i.v27 i.v28 i.v29 i.v30 i.v31

�

My question is how can I ensure that if the output contains a categorical variable (for example v25) that it contains the whole variable rather than just one or several of its categories, as this is no use to me.

�

I have looked in the help for xi and sw but find nothing on how to do this, yet I am sure that it must be possible.

�

Any assistance much appreciated,

�

With kind regards,

�

Rachel Wade

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