st: Abnormal logistic results

[Ras Dondo <ras.dondo@yahoo.com>]

Dear Statalist,
 
I run logistic regression on my data and got an abnormal results and I wanted to ask for advice on how to rectify the problem. I have a dataset containing five variables:
1. condition in a child disease (binary 1/0), 2. mother's age (grouped by 5 year intervals), 3. state (12 states), 4. child's year of birth (grouped into 5 levels), and 5. drug X (binary). My objective was to calculate the OR and associated 95% CI interval of the baby having the disease when the it was exposed to drug in X in the womb, adjusting for maternal age, state, and child's year of birth.
 
I use Stata SE 9.0. I used the following command:
 
xi:logistic disease X i.age i.state i.birth
 
and got OR to be 0 and 95% CI to range from 0-0. 
I had a sample size of 6,168 children of which 89 had the disease with 1 child exposed to the drug, and 6,079 children without the disease with also 1 child exposed to the drug in the womb.
 
Could somebody advise as to what might have gone wrong and whether logistic regression was the way to go?
 
Thanks
 
Ras

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