Exact logistic regression

[_Rose_]

Hi all,

I have a problem in interpreting the result of my exact logistic regression.

Here is my sas program:

PROC LOGISTIC EXACTONLY DATA=COMP_SER1 DESCENDING;
CLASS CL_inj(ref="1")/PARAM=ref;
MODEL SERO_HCV= CL_inj ;
EXACT CL_inj/joint estimate=both;
RUN;

Find attached my output

In the part: "Exact Conditional  tests" I can see that my variable: Cinj that the effect of variable Cinj is significant with all the test.

But when I look at the part: "Exact parameter estimates" I can see that all the parameter of the variable are not significant. 

How can I interprete this?am I wrong with the interpretation of this two part?

How do you interprete this two part?

Thanks for your help!!

Rose

[Kurt_Bremser]

Proc logistic is part of SAS/STAT, so I moved your question here.

[_Rose_]

Thanks!!!

[Rick_SAS]

The parameter estimates show the difference in the effect of each nonreference level compared to the effect of the reference level. So the effect is important in the model, but the levels '2' and '3' are not significantly different than the reference level '1'.

[_Rose_]

Thanks a lot Rick!

[StatDave · Accepted solution]

Following up on Rick's comment... If you just change the reference level of your predictor, then one of the parameters will compare levels 2 and 3 and probably will be significant:

CLASS CL_inj(ref="3")/PARAM=ref;

[_Rose_]

That's right!

Thanks