Hi
I´m new to SAS and statistical analyses. I hope I´m posting in the right forum.
I´m trying to perform a logistic regression on my data.
My dataset contains patients with a chronic disease and a controlgroup. They are pooled in no disease=1, light disease=2 and severe disease=3 (90 patients and 250 controls, matched by age groups). I want to investige the relation to impotence, impotent=1, not impotent=2
My statement is as follows:
proc logistic data = controlsandpatients;
class disease (ref = "1") / param=ref ;
model impotent (event = "1") = disease / lackfit ;
run;
I get a quasi-complete separation problem, The maximum likelihood estimate may not exist. I´ve tried to do an exact test, but that doesen´t solve the problem. Is this the right way to analyse this or should i use PROC FREQ?
I hope you can help me
Best regards
Maria
Since you have control group, do you consider to use conditional logistic regression ?
Thanks for your reply.
I am new to sas programming, and have never done a conditional logistic regression - I tried looking in sas support pages but I am not sure how I would set it up?
There is an example in Documentation about conditional LR.
I remember you should use STRATA statement .
Thanks!
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