Programming the statistical procedures from SAS

Which analysis to choose?

Reply
New Contributor
Posts: 3

Which analysis to choose?

 

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

 

Grand Advisor
Posts: 9,458

Re: Which analysis to choose?

Since you have control group, do you consider to use conditional logistic regression ?

New Contributor
Posts: 3

Re: Which analysis to choose?

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? 

 

Grand Advisor
Posts: 9,458

Re: Which analysis to choose?

There is an example in Documentation about conditional LR.

I remember you should use STRATA statement .

New Contributor
Posts: 3

Re: Which analysis to choose?

Thanks!

Ask a Question
Discussion stats
  • 4 replies
  • 163 views
  • 0 likes
  • 2 in conversation