I am trying to get an output data set from proc logistic containing the odd
ratio estimates and the confidence intervals for them.
The independent variable of interest has 4 classes so 3 of the classes are
compared with the benchmark class (in my case the lowest category).
According with SAS documentation, I was able to compute the odds-ratios for
the three parameters:
Where exposure3, exposure2, and exposure1 are the coefficients produced by
the logistic regression (my values are identical to the ones in the SAS
However, I do have problems computing the confidence intervals for these
According to SAS documentation, it would be = exp(coeff_j +/_ z*sqrt
(variance_j). And the variance is available in the output when using covout
I tried but I am getting totally different results.
Any help would be more than welcomed.
Thank you very much!
Cornel Lencar, MF
School of Occupational and Environmental Hygiene, UBC
#340-2206 East Mall, Vancouver, BC V6T 1Z4