I know how to calculate ages such as =YEAR(P327)-YEAR(D327). However, here
is my problem:

I have four columns:
One is the date of birth of the patient
Another is date patient screeded
The next is date patient randomized
The last is age at randomization

Not all patients get randomized. All patients must be screened, but I only
want the age shown if the patient was randomized. If I copy the formula down
the column, it also grabs the blank field in the randomized column and
returns a erroneous age. How can I fix this so that if a randomized field is
blank, the age at randomization cell will also be blank?

Any help is greatly appreciated.

Thanks,
Kathy