Confused

I have an extensive database of about 4000 names and addresses of patients. I am trying to figure out a way to list all the duplicate addresses on the list- I sometimes see the entire family as patients and don't want to send out mailers to everyone in the same household. I also see a number of pediatric patients. Is there a fast and easy way to both identify these patients and be able to send a letter to the parents, using the parents name? Your assistance would be appreciated.

Hi group. Hope someone can help me with this. I'm designing a layout which has numerous fields, most of which have defined value lists. I'm trying to get it so I can merge them onto a pre-written form letter. They need to be such that there are commas between words and periods after sentences. My fields are such that the user may need to choose more than one value. I've placed the <<merge>> parentheses in the appropriate location, but cannot pre-place commas because the fields may not always have values. Any suggestions on using merged fields more efficiently? Regards, Confused