P-value not provided?!

[Manar Serageldin]

Hello,

I was wondering why does my stata output for chi2 test doesn't give any p-value? I'm comparing two groups with identical proportions of the outcome, I thought I would have a p= 1.000 as in the second chi2 test outcome in the photo attached.

[Maarten Buis]

In the first table there is no variation in the independent variable, so there is nothing Stata can say about any association; there is just no empirical information in your data.

[Hemanshu Kumar]

Comment deleted; irrelevant.

[Manar Serageldin]

Thank you so much Dr. Maarten for your reply.

So what shall I write under p-value heading in the outcome table? would it be correct to write p-value= 1? or shall I leave it empty?

[Maarten Buis]

I would leave it empty. Association is about comparing groups: you only have one group, so there is nothing to compare...

[Clyde Schechter]

I would go a step farther than Maarten Buis has recommended. I would put "N/A" in that cell of the table.

[Manar Serageldin]

Thank you Dr. Maarten and Dr. Clyde. I appreciate your help.